DNA and RNA Overview Quiz
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Questions and Answers

Which enzyme category transfers an amino group between substrates?

  • Ligases
  • Isomerases
  • Transaminases (correct)
  • Hydrolases

    • Which of the following enzymes is classified as a hydrolase?

  • Lipase (correct)
  • Kinasese
  • Transaminases
  • Carboxylases

    • What is the primary function of ligases?

  • Transferring phosphate groups
  • Cleaving chemical bonds using water
  • Catalyzing rearrangements of molecules
  • Joining two substrates with covalent bonds (correct)

    • Which enzyme is responsible for the transfer of a phosphate group?

    <p>Kinase</p> Signup and view all the answers

    Which class of enzymes catalyzes structural rearrangements in a molecule?

    <p>Isomerases</p> Signup and view all the answers

    Which of the following enzymes catalyzes the cleavage of chemical bonds by the addition of water?

    <p>Hydrolase</p> Signup and view all the answers

    What type of reaction is primarily catalyzed by decarboxylases?

    <p>Removing a carboxyl group</p> Signup and view all the answers

    Which enzyme is involved in the hydrolysis of amide linkages in proteins?

    <p>Protease</p> Signup and view all the answers

    Which enzyme catalyzes the removal of COO from pyruvate?

    <p>Pyruvate Decarboxylase</p> Signup and view all the answers

    What type of reaction do oxidoreductases primarily facilitate?

    <p>Oxidation and reduction reactions</p> Signup and view all the answers

    Which of the following enzymes is classified as a transferase?

    <p>Aldolase A</p> Signup and view all the answers

    Which action describes the process of oxidation?

    <p>Loss of electrons</p> Signup and view all the answers

    What product is formed by the action of lactate dehydrogenase?

    <p>Pyruvate</p> Signup and view all the answers

    Which enzyme catalyzes the racemization of alanine?

    <p>Alanine Racemase</p> Signup and view all the answers

    Which of the following best describes isomerases?

    <p>Enzymes that catalyze racemization or transfer of functional groups</p> Signup and view all the answers

    Which enzyme class is responsible for the formation of bonds using ATP?

    <p>Ligases</p> Signup and view all the answers

    What is the primary function of hydrolases?

    <p>Catalyze hydrolysis reactions</p> Signup and view all the answers

    What is a common characteristic of decarboxylases?

    <p>They catalyze the removal of CO2</p> Signup and view all the answers

    What type of reaction do lyases catalyze?

    <p>Cleave C-C, C-O or C-N bonds without hydrolysis or oxidation</p> Signup and view all the answers

    Which enzyme is responsible for the removal of CO2 from a substrate?

    <p>Decarboxylase</p> Signup and view all the answers

    What is the action of hydratases?

    <p>Addition of H2O to a substrate</p> Signup and view all the answers

    Which model describes the interaction where the substrate fits into a rigid active site?

    <p>Lock and key model</p> Signup and view all the answers

    Which type of inhibitor competes with the substrate for binding at the active site?

    <p>Competitive inhibitor</p> Signup and view all the answers

    What effect does competitive inhibition have on Vmax?

    <p>Vmax remains unchanged</p> Signup and view all the answers

    What is the primary role of dehydratases?

    <p>Removal of water from a substrate</p> Signup and view all the answers

    In the induced fit model, what happens to the enzyme upon substrate binding?

    <p>The enzyme undergoes a slight conformational change</p> Signup and view all the answers

    What type of reaction do transferases catalyze?

    <p>Transfer of functional groups</p> Signup and view all the answers

    Which of the following enzymes removes ammonia from a substrate?

    <p>Deaminase</p> Signup and view all the answers

    What defines a holoenzyme?

    <p>An enzyme with a cofactor and an apoenzyme</p> Signup and view all the answers

    What is the primary role of metal ions in enzymes?

    <p>To enhance enzymatic activity by forming metalloenzymes</p> Signup and view all the answers

    Which of the following best describes the function of a catalyst in a chemical reaction?

    <p>It speeds up the reaction without being consumed</p> Signup and view all the answers

    What do the terms low-density lipoproteins (LDLs) and high-density lipoproteins (HDLs) refer to?

    <p>Types of cholesterol transporters in the body</p> Signup and view all the answers

    What type of drug are statins primarily classified as?

    <p>Cholesterol-lowering agents</p> Signup and view all the answers

    What is the primary function of transferases?

    <p>To facilitate group transfer reactions between molecules</p> Signup and view all the answers

    Which of the following describes the function of hydrolases?

    <p>To break down molecules by adding water</p> Signup and view all the answers

    Which enzyme class is responsible for catalyzing the rearrangement of atoms within a molecule?

    <p>Isomerases</p> Signup and view all the answers

    What type of reaction do ligases typically catalyze?

    <p>Formation of larger molecules from smaller ones</p> Signup and view all the answers

    Which of these enzyme types is NOT correctly matched with its function?

    <p>Transferases - catalyze redox reactions</p> Signup and view all the answers

    Decarboxylases are primarily responsible for which type of biochemical reaction?

    <p>Removal of carbon dioxide</p> Signup and view all the answers

    Which of these characteristics is critical to the function of enzymes?

    <p>Enzymes are highly specific for their substrates</p> Signup and view all the answers

    Which enzyme classification includes enzymes that catalyze the breakdown of proteins?

    <p>Hydrolases</p> Signup and view all the answers

    Which option best describes the activity of isomerases?

    <p>They convert one isomer into another.</p> Signup and view all the answers

    What is a common effect of protein denaturation?

    <p>Loss of biological function</p> Signup and view all the answers

    What determines the solubility of fatty acids in water?

    <p>The degree of saturation of the fatty acid</p> Signup and view all the answers

    What effect does the presence of double bonds have on the melting point of fatty acids?

    <p>Decreases the melting point</p> Signup and view all the answers

    How does the solubility of fatty acids generally change with increased carbon chain length?

    <p>Decreases after a certain length</p> Signup and view all the answers

    Which type of fatty acid is more soluble in water?

    <p>Unsaturated fatty acid</p> Signup and view all the answers

    Which statement about even-numbered fatty acids is correct?

    <p>They commonly occur in triglycerides</p> Signup and view all the answers

    What is the characteristic of the negatively charged carboxylate group in fatty acids?

    <p>It enhances water solubility</p> Signup and view all the answers

    Which factor does NOT influence the melting temperature of fatty acids?

    <p>Acidity of the molecule</p> Signup and view all the answers

    What type of fatty acids contain both hydrophilic and hydrophobic groups?

    <p>Amphipathic fatty acids</p> Signup and view all the answers

    Which property decreases with longer hydrocarbon chains in fatty acids?

    <p>Solubility in water</p> Signup and view all the answers

    Which fatty acids are considered sparingly soluble in water?

    <p>Short chain fatty acids</p> Signup and view all the answers

    What effect does the presence of double bonds have on fatty acid solubility?

    <p>Increases solubility</p> Signup and view all the answers

    Which type of fatty acids is typically solid at room temperature?

    <p>Saturated fatty acids</p> Signup and view all the answers

    What characteristic is associated with saturated fatty acids?

    <p>Lead to high low density lipoprotein levels</p> Signup and view all the answers

    What is the relationship between hydrocarbon chain length and water solubility in fatty acids?

    <p>Longer chains are less soluble</p> Signup and view all the answers

    Which fatty acid characteristic tends to decrease as double bond numbers increase?

    <p>Hydrogen saturation</p> Signup and view all the answers

    What type of fatty acids contribute to low density lipoprotein levels in the body?

    <p>Saturated fatty acids</p> Signup and view all the answers

    What is the process called when double bonds in unsaturated fatty acids react with hydrogen gas?

    <p>Hydrogenation</p> Signup and view all the answers

    What roles do antioxidants like vitamin C and vitamin E serve in the context of fatty acids?

    <p>They act as preservatives to prevent oxidation.</p> Signup and view all the answers

    What is the role of a cofactor in enzymatic reactions?

    <p>It is a small molecule that participates in catalysis.</p> Signup and view all the answers

    What is a common characteristic of enzymes regarding their specificity?

    <p>They are highly specific for their substrate.</p> Signup and view all the answers

    What is a primary function of glycolipids in the cell membrane?

    <p>Serving as recognition sites</p> Signup and view all the answers

    Which of the following statements about phospholipids is correct?

    <p>They have a polar head and a nonpolar tail.</p> Signup and view all the answers

    What is the parent structure of phospholipids?

    <p>Phosphatidic acid</p> Signup and view all the answers

    Which compound is formed when sphingosine is combined with a fatty acid?

    <p>Ceramide</p> Signup and view all the answers

    What characterizes the structural role of phospholipids in biological membranes?

    <p>They form lipid bilayers.</p> Signup and view all the answers

    Which of the following is a component of sphingomyelin?

    <p>Ceramide and phosphorylcholine</p> Signup and view all the answers

    What is a defining feature of lipids that are effective in cell membranes?

    <p>They possess both polar and nonpolar portions.</p> Signup and view all the answers

    Which type of lipid is primarily used in the nervous system as part of the myelin sheath?

    <p>Sphingomyelin</p> Signup and view all the answers

    What constitutes a ceramide?

    <p>Sphingosine with a fatty acid</p> Signup and view all the answers

    What is a glycolipid primarily composed of?

    <p>Fatty acid, sphingosine, and a carbohydrate</p> Signup and view all the answers

    What type of linkage connects NANA to the oligosaccharide?

    <p>Alpha linkage</p> Signup and view all the answers

    Which of the following is NOT a component of cerebroside?

    <p>Oligosaccharide</p> Signup and view all the answers

    Which of the following is true about sphingomyelin?

    <p>Primary component in nerve tissue</p> Signup and view all the answers

    What is the primary role of bile acids derived from cholesterol?

    <p>Emulsifier for fatty acids</p> Signup and view all the answers

    Which of the following correctly defines ganglioside?

    <p>Ceramide combined with an oligosaccharide</p> Signup and view all the answers

    What is the characteristic structure of cholesterol?

    <p>Four rings with methyl side chains</p> Signup and view all the answers

    Which component constitutes 25% of all lipids in humans?

    <p>Sphingolipids</p> Signup and view all the answers

    What happens to the double bond at ring B in the formation of bile acids?

    <p>It is lost</p> Signup and view all the answers

    Which of the following best describes the hydrocarbon portion of a phospholipid?

    <p>Hydrophobic and water-hating</p> Signup and view all the answers

    What is the function of cholesterol in the context of cell membranes?

    <p>It provides fluidity to the membrane</p> Signup and view all the answers

    Which bile salt has glycine as its alipathic group at C17?

    <p>Glycocholate</p> Signup and view all the answers

    What is a characteristic of oils compared to fats?

    <p>Oils are predominantly unsaturated.</p> Signup and view all the answers

    What type of reaction is hydrolysis of triacylglycerols considered?

    <p>Reverse of esterification reaction</p> Signup and view all the answers

    Which type of fats is known for being raised during hydrogenation?

    <p>Trans-monounsaturated fats</p> Signup and view all the answers

    Which of the following describes waxes?

    <p>Hydrophobic and water-repellent</p> Signup and view all the answers

    What defines saturated fats compared to oils?

    <p>They are solid or semisolid at room temperature.</p> Signup and view all the answers

    Which omega fatty acids are considered important 'good fats'?

    <p>Omega-3 and Omega-6</p> Signup and view all the answers

    Which amino acid serves as the primary excitatory neurotransmitter in the central nervous system?

    <p>Glutamate</p> Signup and view all the answers

    What is a common property of waxes related to their physical state at room temperature?

    <p>They are solid at room temperature.</p> Signup and view all the answers

    What is the linear sequence of amino acids in a protein known as?

    <p>Primary Structure</p> Signup and view all the answers

    Which amino acid is known to be an inhibitory neurotransmitter in the spinal cord?

    <p>GABA</p> Signup and view all the answers

    What is one of the primary uses of waxes due to their low thermal conductivity?

    <p>As insulators to reduce heat transfer.</p> Signup and view all the answers

    Which neurotransmitter is derived from tryptophan and is involved in mood regulation?

    <p>Serotonin</p> Signup and view all the answers

    Which of the following is an example of a wax produced by a natural secretion?

    <p>Beeswax</p> Signup and view all the answers

    What is the role of enzymes in biochemical reactions?

    <p>Decreases the activation energy required.</p> Signup and view all the answers

    Which of the following neurotransmitters is primarily involved in the fight-or-flight response?

    <p>Epinephrine</p> Signup and view all the answers

    What happens to enzymes during the chemical reaction they catalyze?

    <p>They are regenerated and reused.</p> Signup and view all the answers

    Which of the following compounds may be produced from the oxidation of triacylglycerols?

    <p>Aldehydes or carboxylic acids</p> Signup and view all the answers

    What is a characteristic feature of waxes concerning their chemical stability?

    <p>Relatively chemically stable.</p> Signup and view all the answers

    What is the effect of double bonds in fatty acids on their melting point?

    <p>Decreases their melting point.</p> Signup and view all the answers

    What type of reaction do waxes undergo during saponification?

    <p>Hydrolysis to produce fatty acid salts.</p> Signup and view all the answers

    What type of bond does an uncompetitive inhibitor primarily form with the enzyme?

    <p>Covalent bond</p> Signup and view all the answers

    Which class of inhibitors binds to the enzyme-substrate complex to prevent the reaction?

    <p>Uncompetitive inhibitors</p> Signup and view all the answers

    What is a characteristic effect of suicide inhibitors on enzymes?

    <p>They permanently inactivate the enzyme.</p> Signup and view all the answers

    Which of the following statements is true regarding heavy metal ions as inhibitors?

    <p>They can inhibit enzymes by displacing metal cofactors.</p> Signup and view all the answers

    What is the primary action of organophosphate insecticides on enzymes?

    <p>They permanently inhibit acetylcholinesterase.</p> Signup and view all the answers

    In an enzyme-catalyzed reaction, what is the role of a substrate?

    <p>To bind to the enzyme and undergo a chemical change.</p> Signup and view all the answers

    What is the effect of irreversible inhibitors on enzymes?

    <p>They create a stable, covalent bond with the enzyme.</p> Signup and view all the answers

    Which statement describes how uncompetitive inhibitors affect enzyme kinetics?

    <p>They lower Vmax without changing Km.</p> Signup and view all the answers

    What role does a flexible pocket in enzymes play in substrate binding?

    <p>It accommodates changes in substrate shape during binding.</p> Signup and view all the answers

    What defines a second-order reaction in enzymatic kinetics?

    <p>It depends on the concentration of two reactants.</p> Signup and view all the answers

    Which amino acid is the only one that is not chiral?

    <p>Glycine</p> Signup and view all the answers

    What characteristic do chiral α-carbon atoms possess?

    <p>They have four different groups attached.</p> Signup and view all the answers

    Which of the following amino acids is purely ketogenic?

    <p>Leucine</p> Signup and view all the answers

    What type of amino acid side chain is characterized by being hydrophobic?

    <p>Nonpolar side chain</p> Signup and view all the answers

    Which of the following classifications describes amino acids that can give both glucose and ketone bodies?

    <p>Mixed ketogenic and glucogenic amino acids</p> Signup and view all the answers

    Which amino acid can be classified as having a polar neutral side chain?

    <p>Asparagine</p> Signup and view all the answers

    What is true about stereoisomers in relation to amino acids?

    <p>They have varying arrangements of atoms in space.</p> Signup and view all the answers

    Which statement is accurate concerning the classification of amino acids?

    <p>Amino acids can be categorized based on their side chain properties.</p> Signup and view all the answers

    Which amino acid has a side chain that is classified as polar acidic?

    <p>Aspartic acid</p> Signup and view all the answers

    What indicates that an amino acid has a polar basic side chain?

    <p>It contains a positive charge and an amino group.</p> Signup and view all the answers

    What is the most abundant type of RNA involved in protein synthesis?

    <p>Ribosomal RNA (rRNA)</p> Signup and view all the answers

    What role does transfer RNA (tRNA) play in protein synthesis?

    <p>Carries amino acids to the ribosome</p> Signup and view all the answers

    In the central dogma of molecular biology, which process involves the reading and carrying of genetic messages?

    <p>Transcription</p> Signup and view all the answers

    Which type of RNA associates with ribosomal proteins to form the complete functional ribosome?

    <p>Ribosomal RNA (rRNA)</p> Signup and view all the answers

    What is the primary outcome of the translation process in the central dogma?

    <p>Synthesis of proteins</p> Signup and view all the answers

    Which of the following RNA types is responsible for transporting amino acids during protein synthesis?

    <p>Transfer RNA (tRNA)</p> Signup and view all the answers

    How is ribosomal RNA (rRNA) described in terms of abundance among RNA types?

    <p>Most abundant type of RNA</p> Signup and view all the answers

    What does an uncompetitive inhibitor do in an enzyme-catalyzed reaction?

    <p>Decreases the Vmax without affecting the Km</p> Signup and view all the answers

    Suicide inhibitors permanently alter the enzyme by forming what type of bond?

    <p>Covalent bond</p> Signup and view all the answers

    Which of the following statements accurately describes heavy metal ions as enzyme inhibitors?

    <p>They inhibit enzymes by forming covalent bonds with amino acid residues</p> Signup and view all the answers

    What defines the action of organophosphate insecticides on enzymes?

    <p>They serve as irreversible inhibitors by inactivating the acetylcholinesterase enzyme</p> Signup and view all the answers

    How does the binding of a competitive inhibitor affect enzyme activity?

    <p>It decreases the amount of enzyme available for substrate binding</p> Signup and view all the answers

    What are cerebrosides composed of?

    <p>Ceramide and sugar</p> Signup and view all the answers

    What type of linkage is formed when NANA is attached to an oligosaccharide?

    <p>Alpha linkage</p> Signup and view all the answers

    What is the primary function of sphingomyelin in the human body?

    <p>Insulation in nerve tissue</p> Signup and view all the answers

    Which statement correctly describes cholesterol?

    <p>It is a precursor for bile acids.</p> Signup and view all the answers

    What is the role of bile acids derived from cholesterol?

    <p>Emulsifying fatty acids</p> Signup and view all the answers

    What characteristic is common to the polar sites of phospholipids?

    <p>They are hydrophilic.</p> Signup and view all the answers

    How are oligosaccharides linked to ceramide in gangliosides?

    <p>Beta linkages</p> Signup and view all the answers

    Which enzyme is classified as a mutase?

    <p>Alanine Transaminase</p> Signup and view all the answers

    Which enzyme catalyzes the formation of new bonds between substrates with the participation of ATP?

    <p>Synthetase</p> Signup and view all the answers

    What is the primary composition of cerebrosides when the sugar is glucose?

    <p>Glucocerebroside</p> Signup and view all the answers

    What happens to bile acids when the double bond at ring B is lost?

    <p>They are converted into steroids.</p> Signup and view all the answers

    What reaction do carboxylases typically catalyze?

    <p>Addition of CO2 to a substrate</p> Signup and view all the answers

    Which enzyme is responsible for the hydrolysis of sugar phosphate ester bonds in nucleic acids?

    <p>Nuclease</p> Signup and view all the answers

    Which type of enzymes catalyze the cleavage of high-energy phosphate bonds?

    <p>Hydrolases</p> Signup and view all the answers

    What do transaminases do in biochemical processes?

    <p>Transfer amino groups</p> Signup and view all the answers

    Which enzyme is responsible for catalyzing the condensation of pyruvate and CO2?

    <p>Pyruvate carboxylase</p> Signup and view all the answers

    Which classification of enzymes includes those that catalyze reactions involving structural rearrangements?

    <p>Isomerases</p> Signup and view all the answers

    What type of reaction does a dehydratase catalyze?

    <p>Removal of H2O from a substrate</p> Signup and view all the answers

    In the lock and key model, how does the substrate interact with the enzyme?

    <p>Substrate binds to a site whose shape complements its own</p> Signup and view all the answers

    What does a competitive inhibitor do in enzyme kinetics?

    <p>Competes with the substrate for binding at the active site</p> Signup and view all the answers

    What is the characteristic of non-competitive inhibition?

    <p>It binds to a site other than the active site and changes the enzyme's shape</p> Signup and view all the answers

    Which type of bonds can lyases cleave?

    <p>C-C, C-O, or C-N bonds</p> Signup and view all the answers

    What happens to an enzyme's structure during the induced fit model?

    <p>Enzyme undergoes a slight conformational change</p> Signup and view all the answers

    Which of the following is an example of a non-competitive inhibitor?

    <p>Cyanide</p> Signup and view all the answers

    What is the role of hydratases in biochemical reactions?

    <p>To add H2O to a substrate</p> Signup and view all the answers

    How does the differential effect of competitive inhibition on Km manifest?

    <p>Km increases, indicating decreased affinity</p> Signup and view all the answers

    Which feature is not associated with the lock and key model?

    <p>Flexibility of enzyme structure</p> Signup and view all the answers

    What is the primary source of fats?

    <p>Animal sources</p> Signup and view all the answers

    Which type of fat is considered a 'good fat'?

    <p>Monounsaturated fat</p> Signup and view all the answers

    What is the structure of taurocholate defined by?

    <p>A taurine group</p> Signup and view all the answers

    What is a common property of waxes?

    <p>Water-repellent</p> Signup and view all the answers

    Which reaction describes the breakdown of triacylglycerols?

    <p>Hydrolysis</p> Signup and view all the answers

    What type of fatty acids are omega-3 and omega-6 classified as?

    <p>Polyunsaturated fats</p> Signup and view all the answers

    Which type of fat is predominantly found in oils?

    <p>Unsaturated fat</p> Signup and view all the answers

    Which enzyme class is responsible for forming a new bond between two substrates using ATP?

    <p>Ligases</p> Signup and view all the answers

    Which enzyme reaction involves the transfer of an amino group between substrates?

    <p>Transaminases</p> Signup and view all the answers

    Which of the following enzymes catalyzes the conversion of pyruvate to CO2?

    <p>Carboxylases</p> Signup and view all the answers

    Pyruvate carboxylase encompasses which type of enzymatic activity?

    <p>Condensation of substrates</p> Signup and view all the answers

    What type of reaction do hydrolases typically facilitate?

    <p>Cleavage by addition of water</p> Signup and view all the answers

    What defines the action of kinases in enzymatic reactions?

    <p>Transfer of phosphate groups</p> Signup and view all the answers

    What is the primary role of proteases in biochemical reactions?

    <p>Hydrolysis of amide linkages</p> Signup and view all the answers

    What is the primary consequence of the formation of toxic aggregates in the brain regarding Alzheimer's disease?

    <p>Contributing to the development of the disease</p> Signup and view all the answers

    What type of protein aggregate is associated with Parkinson's disease?

    <p>Lewy bodies</p> Signup and view all the answers

    What is the process called when a protein loses its natural shape and functionality?

    <p>Denaturation</p> Signup and view all the answers

    Which of the following is NOT a factor that affects protein denaturation?

    <p>Light exposure</p> Signup and view all the answers

    What type of bond links amino acids together in proteins?

    <p>Peptide bond</p> Signup and view all the answers

    Which amino acid is unique in not being chiral?

    <p>Glycine</p> Signup and view all the answers

    How many chiral carbons does threonine possess?

    <p>Two</p> Signup and view all the answers

    Which of the following correctly describes nonpolar amino acids?

    <p>They contain uncharged hydrocarbon groups.</p> Signup and view all the answers

    Which group of amino acids is classified as purely ketogenic?

    <p>Lysine and Leucine</p> Signup and view all the answers

    How are stereoisomers defined?

    <p>Compounds with the same molecular formula but differ in arrangement of atoms.</p> Signup and view all the answers

    What characterizes a polar acidic amino acid?

    <p>Contains 1 amino group and 2 carboxyl groups.</p> Signup and view all the answers

    What type of interaction is associated with nonpolar amino acids?

    <p>Hydrophobic interactions</p> Signup and view all the answers

    Which amino acids can yield both ketone bodies and glucose?

    <p>Isoleucine and Phenylalanine</p> Signup and view all the answers

    Which property best describes the side chains of polar neutral amino acids?

    <p>Are hydrophilic and soluble in water.</p> Signup and view all the answers

    What aspect of amino acids influences their classification based on metablolic products?

    <p>The nature of their side chains.</p> Signup and view all the answers

    What is primarily responsible for stabilizing the alpha helix structure in proteins?

    <p>Hydrogen bonds</p> Signup and view all the answers

    Which type of protein is characterized by a compact, spherical shape and is often water-soluble?

    <p>Globular proteins</p> Signup and view all the answers

    What type of interaction holds the tertiary structure of a protein together?

    <p>Interactions between R groups</p> Signup and view all the answers

    Which structure represents multiple polypeptide chains coming together?

    <p>Quaternary structure</p> Signup and view all the answers

    What happens to misfolded proteins within a cell?

    <p>They are tagged for degradation</p> Signup and view all the answers

    How many amino acids typically define a peptide?

    <p>Less than 50</p> Signup and view all the answers

    Which of the following examples is a fibrous protein?

    <p>Collagen</p> Signup and view all the answers

    What is the role of chaperones in protein folding?

    <p>To assist in correct protein folding</p> Signup and view all the answers

    Which pathological condition is associated with protein misfolding?

    <p>Alzheimer's disease</p> Signup and view all the answers

    What type of bonds are involved in quaternary structures of proteins?

    <p>Similar interactions as tertiary structure</p> Signup and view all the answers

    What is the primary role of messenger RNA (mRNA)?

    <p>To carry information for protein synthesis to the ribosome.</p> Signup and view all the answers

    Which sequence of nucleotides is referred to as a codon?

    <p>A sequence of three mRNA nucleotides that codes for an amino acid.</p> Signup and view all the answers

    What is a key function of ribosomal RNA (rRNA) during translation?

    <p>To form the structure of the ribosome.</p> Signup and view all the answers

    What is the process of DNA replication primarily responsible for?

    <p>Doubling the amount of DNA before cell division.</p> Signup and view all the answers

    What role do stop codons play in protein synthesis?

    <p>They signal the end of translation for a polypeptide.</p> Signup and view all the answers

    During which phase does DNA replication take place?

    <p>During interphase.</p> Signup and view all the answers

    What is true regarding the size and sequence variability of mRNA?

    <p>mRNA is very heterogeneous in size and base sequence.</p> Signup and view all the answers

    What is the primary function of eicosanoids?

    <p>Local hormonal mediation</p> Signup and view all the answers

    What is the composition of a triglyceride?

    <p>One glycerol and three fatty acids</p> Signup and view all the answers

    What is the energy yield from triglycerides compared to carbohydrates and proteins?

    <p>Greater than carbohydrates</p> Signup and view all the answers

    How do simple triacylglycerols differ from mixed triacylglycerols?

    <p>They always have the same fatty acids</p> Signup and view all the answers

    What are eicosanoids derived from?

    <p>Arachidonic acid</p> Signup and view all the answers

    What is the role of DHA in development?

    <p>Neural and visual function</p> Signup and view all the answers

    What is a characteristic of sphingolipids?

    <p>Their parent structure is sphingosine</p> Signup and view all the answers

    What is a function of simple glycerides?

    <p>Energy storage</p> Signup and view all the answers

    What happens to eicosanoids after they exert their effects?

    <p>They are rapidly degraded</p> Signup and view all the answers

    What distinguishes lyases from other enzymes?

    <p>They break bonds without oxidation or hydrolysis.</p> Signup and view all the answers

    In the lock and key model, what aspect of enzyme-substrate interaction is considered?

    <p>The exact fit of the substrate into a rigid active site.</p> Signup and view all the answers

    Which statement best describes non-competitive inhibition?

    <p>The inhibitor binds to a site other than the active site.</p> Signup and view all the answers

    How does substrate concentration affect the maximum velocity (Vmax) in competitive inhibition?

    <p>Vmax can be reached with increased substrate concentration.</p> Signup and view all the answers

    What is the primary difference in the induced fit model compared to the lock and key model?

    <p>The enzyme undergoes a conformational change upon binding.</p> Signup and view all the answers

    What are coenzymes primarily derived from?

    <p>Vitamins</p> Signup and view all the answers

    What is the role of a catalyst in a chemical reaction?

    <p>To speed up the reaction without being used up</p> Signup and view all the answers

    What is produced when unsaturated fatty acids undergo hydrogenation?

    <p>Carbon-carbon single bonds</p> Signup and view all the answers

    Which of the following best describes the role of antioxidants like vitamin C and E in food?

    <p>They prevent unwanted oxidation processes.</p> Signup and view all the answers

    What type of cholesterol do low-density lipoproteins (LDLs) primarily carry?

    <p>Cholesterol from the liver to tissues</p> Signup and view all the answers

    What is the primary function of enzymes in a chemical reaction?

    <p>They lower the activation energy.</p> Signup and view all the answers

    Which statement about statins is true?

    <p>They help to lower cholesterol levels</p> Signup and view all the answers

    What are cofactors in the context of enzyme activity?

    <p>Small molecules that assist enzyme function.</p> Signup and view all the answers

    What is a key characteristic of a holoenzyme?

    <p>It is inactive without its cofactor</p> Signup and view all the answers

    What happens to the activation energy in the presence of a catalyst?

    <p>It decreases</p> Signup and view all the answers

    Which statement about apoenzyme is accurate?

    <p>It requires a cofactor to be active.</p> Signup and view all the answers

    Why might fats and oils develop objectionable odors over time?

    <p>Due to oxidation processes.</p> Signup and view all the answers

    Which of the following is NOT a type of cofactor?

    <p>Complex carbohydrates</p> Signup and view all the answers

    What is meant by the term 'apoenzyme'?

    <p>An inactive form of an enzyme without its cofactor</p> Signup and view all the answers

    What differentiates saturated fatty acids from unsaturated ones?

    <p>Presence of no double bonds.</p> Signup and view all the answers

    How do high-density lipoproteins (HDLs) function?

    <p>They transport excess cholesterol from tissues back to the liver</p> Signup and view all the answers

    What is the consequence of hydrogenating unsaturated fatty acids?

    <p>Conversion to saturated fatty acids.</p> Signup and view all the answers

    Which of the following statements is false regarding enzyme specificity?

    <p>Enzymes can act on a wide variety of substrates.</p> Signup and view all the answers

    What does hydrogenation primarily achieve in unsaturated fatty acids?

    <p>Creation of fewer unsaturated bonds.</p> Signup and view all the answers

    Which form of DNA is considered the most stable and is predominant in physiological conditions?

    <p>B form</p> Signup and view all the answers

    What type of mutation is characterized by a change in a single base pair that does not affect the activity of the resulting protein?

    <p>Silent mutation</p> Signup and view all the answers

    Which form of DNA has a left-handed helical structure and a zigzag appearance?

    <p>Z form</p> Signup and view all the answers

    What is the result of a missense mutation in DNA?

    <p>Substitution of one amino acid for another</p> Signup and view all the answers

    In which condition is the A form of DNA favored?

    <p>Solutions lacking water</p> Signup and view all the answers

    Which type of mutation introduces a stop codon into the protein sequence?

    <p>Nonsense mutation</p> Signup and view all the answers

    What is a common misconception about mutations?

    <p>They are always harmful</p> Signup and view all the answers

    Which amino acid is classified as the only non-chiral amino acid?

    <p>Glycine</p> Signup and view all the answers

    What characterizes amino acids with nonpolar side chains?

    <p>Uncharged hydrocarbon groups or benzene rings</p> Signup and view all the answers

    Which amino acids are solely classified as ketogenic?

    <p>Leucine and Lysine</p> Signup and view all the answers

    Which type of amino acids has side chains that are hydrophilic?

    <p>Polar acidic side chains</p> Signup and view all the answers

    How many chiral carbons are found in threonine and isoleucine respectively?

    <p>2 each</p> Signup and view all the answers

    What is the main structural role of phospholipids in biological membranes?

    <p>They form lipid bilayers</p> Signup and view all the answers

    Which of the following components primarily constitutes cerebrosides?

    <p>Fatty acid, sphingosine, and a carbohydrate</p> Signup and view all the answers

    What is the basic structure found in all phosphoglycerides?

    <p>Phosphatidic acid</p> Signup and view all the answers

    What is the purpose of antioxidants like vitamin C and vitamin E in food preservation?

    <p>They prevent the formation of free radicals.</p> Signup and view all the answers

    Which characteristic is essential for a lipid to function properly in a membrane?

    <p>Having both polar and nonpolar portions</p> Signup and view all the answers

    What is sphingomyelin composed of?

    <p>Ceramide and phosphorylcholine</p> Signup and view all the answers

    What type of bond is formed between carbon atoms during the hydrogenation of unsaturated fatty acids?

    <p>Single bonds</p> Signup and view all the answers

    What is an apoenzyme?

    <p>The protein component of an enzyme.</p> Signup and view all the answers

    In what major tissue are ceramide derivatives primarily utilized?

    <p>Nerve tissues for myelin sheath formation</p> Signup and view all the answers

    Which component of phospholipids is often involved in cellular recognition?

    <p>Carbohydrate chains</p> Signup and view all the answers

    How do antioxidants prevent unwanted oxidation in fats and oils?

    <p>By neutralizing free radicals.</p> Signup and view all the answers

    Which statement accurately describes cofactors in enzyme activity?

    <p>They participate in the catalytic process.</p> Signup and view all the answers

    What key feature differentiates phospholipids from other lipid classes?

    <p>Inclusion of a phosphate group</p> Signup and view all the answers

    How many percent of total lipids in man are represented by glycolipids?

    <p>25%</p> Signup and view all the answers

    What is the primary chemical reaction involved in the hydrogenation of triacylglycerols?

    <p>Reduction reactions.</p> Signup and view all the answers

    What type of fatty acids are formed from the hydrogenation of unsaturated fatty acids?

    <p>Saturated fatty acids.</p> Signup and view all the answers

    What happens to double bonds in unsaturated fatty acids during hydrogenation?

    <p>They are converted to carbon–carbon single bonds.</p> Signup and view all the answers

    Which type of enzyme catalyzes the transfer of a functional group within a single molecule?

    <p>Isomerases</p> Signup and view all the answers

    What is the primary action of lipases in biochemical reactions?

    <p>Hydrolyzing ester linkages</p> Signup and view all the answers

    Which enzyme is known for catalyzing the cleavage of a high-energy phosphate bond in the presence of water?

    <p>Pyrophosphatase</p> Signup and view all the answers

    What is the main feature of ligases in biochemical reactions?

    <p>They join two substrates with covalent bonds.</p> Signup and view all the answers

    Which enzyme transfers an amino group from alanine to another substrate?

    <p>Transaminase</p> Signup and view all the answers

    Which of the following enzymes directly utilizes ATP to form new bonds?

    <p>Synthetases</p> Signup and view all the answers

    What type of reaction do carboxylases primarily catalyze?

    <p>Formation of a new bond with CO2</p> Signup and view all the answers

    Which enzyme catalyzes the hydrolysis of glycosidic bonds in carbohydrates?

    <p>Carbohydrase</p> Signup and view all the answers

    Which class of enzymes is specifically involved in the hydrolysis of amide linkages in proteins?

    <p>Hydrolases</p> Signup and view all the answers

    What is a common function of kinases in biological systems?

    <p>Adding phosphate groups</p> Signup and view all the answers

    Which form of DNA is the most stable and predominantly found in physiological conditions?

    <p>B form</p> Signup and view all the answers

    What type of mutation results in no change in the activity of the protein?

    <p>Silent mutation</p> Signup and view all the answers

    Which type of mutation results in the substitution of one amino acid for another?

    <p>Missense mutation</p> Signup and view all the answers

    What feature does the Z form of DNA exhibit?

    <p>Zigzag appearance</p> Signup and view all the answers

    What does the term 'mutation' generally imply?

    <p>Change in the usual DNA sequence</p> Signup and view all the answers

    Which of these mutations leads to the introduction of a premature stop codon?

    <p>Nonsense mutation</p> Signup and view all the answers

    Which of the following conditions favors the formation of A form DNA?

    <p>Solutions lacking water</p> Signup and view all the answers

    What is the primary function of HMG-CoA reductase?

    <p>Inhibits the formation of cholesterol</p> Signup and view all the answers

    Which statement describes the action of oxidoreductases?

    <p>They facilitate the transfer of electrons and hydrogen atoms.</p> Signup and view all the answers

    What type of reaction is catalyzed by isomerases?

    <p>Conversion of substrates to different forms</p> Signup and view all the answers

    What type of sugar is associated with glucocerebroside?

    <p>Glucose</p> Signup and view all the answers

    What is the main action of dehydrogenases?

    <p>Introduce double bonds by removing hydrogen atoms</p> Signup and view all the answers

    Which linkage connects the oligosaccharide to ceramide in gangliosides?

    <p>Beta linkage</p> Signup and view all the answers

    Which enzyme is known to facilitate the transfer of amino groups specifically?

    <p>Alanine racemase</p> Signup and view all the answers

    Which component is NOT part of the structure of sphingomyelin?

    <p>Oligosaccharide</p> Signup and view all the answers

    Which lipid is primarily found in nerve tissue as part of the myelin sheath?

    <p>Sphingomyelin</p> Signup and view all the answers

    What type of acid is linked to the oligosaccharide in gangliosides?

    <p>Sialic acid</p> Signup and view all the answers

    What is a characteristic feature of cholesterol's molecular structure?

    <p>Consists of four fused rings</p> Signup and view all the answers

    Which of the following statements about sulfatides is true?

    <p>They are sulfated sugars combined with ceramide.</p> Signup and view all the answers

    What do antioxidants do in relation to fats and oils?

    <p>They act as preservatives to prevent oxidation.</p> Signup and view all the answers

    What is produced during the hydrogenation of unsaturated fatty acids?

    <p>Carbon-carbon single bonds.</p> Signup and view all the answers

    What role do cofactors play in enzyme function?

    <p>They assist the apoenzyme in catalysis.</p> Signup and view all the answers

    Why is it important to avoid alteration of reaction equilibrium?

    <p>It maintains a balance of reactants and products.</p> Signup and view all the answers

    What characterizes enzymes in terms of their specificity?

    <p>Enzymes are highly specific for their substrate.</p> Signup and view all the answers

    What type of reaction can convert unsaturated fatty acids into saturated fatty acids?

    <p>Hydrogenation.</p> Signup and view all the answers

    What is an effect of rancidity in fats and oils?

    <p>They develop objectionable odors.</p> Signup and view all the answers

    How are hydrogen gas and double bonds in unsaturated fatty acids related?

    <p>Hydrogen gas reacts with double bonds to form single bonds.</p> Signup and view all the answers

    What is a holoenzyme composed of?

    <p>An apoenzyme and a cofactor</p> Signup and view all the answers

    What role do metal ions play in metalloenzymes?

    <p>They are required for enzyme function</p> Signup and view all the answers

    What is a characteristic of a catalyst in a chemical reaction?

    <p>It remains unchanged after the reaction</p> Signup and view all the answers

    What is the primary function of low-density lipoproteins (LDLs)?

    <p>They carry cholesterol from the liver</p> Signup and view all the answers

    What is the main function of high-density lipoproteins (HDLs)?

    <p>To transport excess cholesterol to the liver</p> Signup and view all the answers

    What type of drug are statins classified as?

    <p>Cholesterol-lowering drugs</p> Signup and view all the answers

    What is the substrate of an enzyme?

    <p>The reactants that are activated by the enzyme</p> Signup and view all the answers

    How do catalysts affect the activation energy of a reaction?

    <p>They lower the activation energy</p> Signup and view all the answers

    What type of molecules can act as prosthetic groups?

    <p>Small organic molecules</p> Signup and view all the answers

    What characteristic makes fatty acids amphipathic?

    <p>They have both hydrophilic and hydrophobic groups.</p> Signup and view all the answers

    How does the solubility of fatty acids generally change with increased chain length?

    <p>Decreases as the chain gets longer.</p> Signup and view all the answers

    Which type of fatty acid is classified as solid at room temperature?

    <p>Saturated fatty acids</p> Signup and view all the answers

    What is the effect of double bonds on the solubility of fatty acids?

    <p>They increase the solubility in water.</p> Signup and view all the answers

    What group is present in fatty acids that contributes to their polar nature?

    <p>Carboxyl group</p> Signup and view all the answers

    What occurs as the number of double bonds in fatty acids increases?

    <p>Their hydrocarbon chain gets shorter.</p> Signup and view all the answers

    What type of cholesterol is associated with saturated fatty acids?

    <p>Bad cholesterol (LDL)</p> Signup and view all the answers

    What property of waxes allows them to melt and flow easily when heated?

    <p>Low melting point</p> Signup and view all the answers

    Which of the following types of wax is a secretion from the sebaceous glands of the skin?

    <p>Sebum</p> Signup and view all the answers

    What happens to double bonds in triacylglycerols during oxidation?

    <p>They break and form carboxylic acids</p> Signup and view all the answers

    Which of the following properties makes waxes suitable as insulators?

    <p>Low thermal conductivity</p> Signup and view all the answers

    Which of the following waxes is often used for baby skin treatments?

    <p>Lanolin</p> Signup and view all the answers

    What is formed when ceramide is combined with glucose?

    <p>Glucocerebroside</p> Signup and view all the answers

    What type of linkage is primarily found between ceramide and oligosaccharides in gangliosides?

    <p>Beta linkages</p> Signup and view all the answers

    Which component is added to ceramide and oligosaccharides to form gangliosides?

    <p>Sialic acid</p> Signup and view all the answers

    What is the structural characteristic of cholesterol?

    <p>Four fused rings</p> Signup and view all the answers

    Which of the following substances acts as an emulsifier for fatty acids?

    <p>Bile acids</p> Signup and view all the answers

    What type of sugar is associated with the formation of lactocerebroside?

    <p>Lactose</p> Signup and view all the answers

    Which characteristic best describes the hydrocarbon part of a phospholipid?

    <p>Hydrophobic in nature</p> Signup and view all the answers

    Which of the following statements is true about the linkage of NANA to the oligosaccharide?

    <p>It is through an Alpha linkage</p> Signup and view all the answers

    What percentage of all lipids in humans are sphingolipids?

    <p>25%</p> Signup and view all the answers

    What is the main function of eicosanoids in the body?

    <p>Promotion of inflammation and smooth muscle contraction</p> Signup and view all the answers

    What is the energy yield of triacylglycerol compared to carbohydrates and proteins?

    <p>9 cal/g, which is greater than carbohydrates and proteins</p> Signup and view all the answers

    How are simple glycerides formed?

    <p>By esterifying glycerol with one or more fatty acids</p> Signup and view all the answers

    What differentiates a mixed triacylglycerol from a simple triacylglycerol?

    <p>Mixed triacylglycerols have different fatty acids attached to glycerol</p> Signup and view all the answers

    Which statement about sphingolipids is accurate?

    <p>They have an 18-carbon parent structure called sphingosine</p> Signup and view all the answers

    What is a common characteristic of triacylglycerols?

    <p>They are compact and light, containing no water</p> Signup and view all the answers

    What physiological role does DHA play in the body?

    <p>It supports proper neural and visual function development</p> Signup and view all the answers

    What describes the composition of triacylglycerols?

    <p>They consist of one glycerol molecule and three fatty acids</p> Signup and view all the answers

    What does the term 'esterification' refer to in the context of lipids?

    <p>The formation of bonds between glycerol and fatty acids</p> Signup and view all the answers

    Which component is necessary to classify a lipid as a phospholipid?

    <p>A phosphate group</p> Signup and view all the answers

    Glycolipids are mainly characterized by the presence of which components?

    <p>A fatty acid, sphingosine, and a carbohydrate</p> Signup and view all the answers

    What structure forms the basis for all phosphoglycerides?

    <p>Phosphatidic acid</p> Signup and view all the answers

    What component do ceramides consist of?

    <p>Sphingosine and a fatty acid</p> Signup and view all the answers

    What is the function of sphingomyelin in the body?

    <p>Forms myelin sheath in nerve tissues</p> Signup and view all the answers

    What is a key characteristic of the structure of phospholipids?

    <p>Nonpolar tail and polar head</p> Signup and view all the answers

    Which of the following best describes the composition of a typical glycolipid?

    <p>Fatty acid, sphingosine, and a carbohydrate</p> Signup and view all the answers

    In terms of cellular functions, what role do lipids in the plasma membrane primarily serve?

    <p>Insulatory function and recognition sites</p> Signup and view all the answers

    Which lipid is known as the basic structural element found in all phosphoglycerides?

    <p>Phosphatidic acid</p> Signup and view all the answers

    What effect does the degree of saturation have on the melting temperature of fatty acids?

    <p>More saturated fatty acids lead to higher melting temperatures.</p> Signup and view all the answers

    Which fatty acid is an example of a polyunsaturated fatty acid?

    <p>Arachidonic acid (C20:4)</p> Signup and view all the answers

    What chain length class is lauric acid categorized into?

    <p>Medium chain</p> Signup and view all the answers

    How does increasing the chain length of a fatty acid generally affect its melting temperature?

    <p>It increases the melting temperature.</p> Signup and view all the answers

    What characteristic of unsaturated fatty acids affects their melting point compared to saturated fatty acids?

    <p>Increased disorder in molecular structure</p> Signup and view all the answers

    What type of fatty acid is identified as having one double bond?

    <p>Monounsaturated fatty acid</p> Signup and view all the answers

    Which of the following statements about long chain fatty acids is true?

    <p>They require more energy to break intermolecular forces.</p> Signup and view all the answers

    What is the primary feature of the alpha helix structure in proteins?

    <p>Stabilized by hydrogen bonds</p> Signup and view all the answers

    Which type of protein is typically characterized by a long, fibrous shape and is often insoluble in water?

    <p>Fibrous proteins</p> Signup and view all the answers

    What role do chaperones play in the context of protein structure?

    <p>They prevent proteins from misfolding</p> Signup and view all the answers

    How are proteins distinguished from peptides based on amino acid count?

    <p>Proteins contain more than 50 amino acids</p> Signup and view all the answers

    Which of the following accurately describes the quaternary structure of proteins?

    <p>It involves individual polypeptide chains interacting with each other</p> Signup and view all the answers

    Which of the following describes the structure of cerebroside?

    <p>A ceramide linked with a sugar</p> Signup and view all the answers

    What type of sugar is linked to create a galactocerebroside?

    <p>Galactose</p> Signup and view all the answers

    Which type of linkage connects NANA to the oligosaccharide in gangliosides?

    <p>Alpha linkage</p> Signup and view all the answers

    Which component is found in 25% of all lipids in humans?

    <p>Sphingolipids</p> Signup and view all the answers

    What is the primary function of bile acids derived from cholesterol?

    <p>Emulsification of fatty acids</p> Signup and view all the answers

    Which of the following correctly identifies the hydrophilic and hydrophobic parts of a phospholipid?

    <p>Hydrophilic part is the polar head, hydrophobic part is the hydrocarbon tail</p> Signup and view all the answers

    What is the molecular structure feature of cholesterol?

    <p>Four fused rings with methyl side chains</p> Signup and view all the answers

    What is the primary role of sphingomyelin in biological systems?

    <p>Cell membrane structure, particularly in nerve tissues</p> Signup and view all the answers

    What specific double bond characteristic is mentioned in the context of cholesterol?

    <p>Between C5 and C6 of ring B</p> Signup and view all the answers

    Which amino acids are classified as glucogenic?

    <p>Amino acids that yield products entering glucose formation</p> Signup and view all the answers

    What is a primary use of waxes due to their low thermal conductivity?

    <p>As insulators</p> Signup and view all the answers

    What is the role of glutamate in the central nervous system?

    <p>It functions as the primary excitatory neurotransmitter</p> Signup and view all the answers

    Which of the following is an example of a wax produced by bees?

    <p>Beeswax</p> Signup and view all the answers

    Which neurotransmitter is derived from tyrosine and involved in reward and movement?

    <p>Dopamine</p> Signup and view all the answers

    What occurs during the oxidation of double bonds in triacylglycerols?

    <p>Breakage of c=c bonds</p> Signup and view all the answers

    Which level of protein structure refers to the linear sequence of amino acids?

    <p>Primary structure</p> Signup and view all the answers

    What does the secondary structure of a protein refer to?

    <p>Local folding patterns of the polypeptide chain</p> Signup and view all the answers

    What is the product of hydrolysis of waxes in basic solutions?

    <p>Glycerol and fatty acids</p> Signup and view all the answers

    What characteristic of waxes contributes to their use in reducing friction?

    <p>Lubricating properties</p> Signup and view all the answers

    Which neurotransmitter is primarily inhibitory and especially active in the spinal cord?

    <p>GABA</p> Signup and view all the answers

    Which of the following waxes is also used as a treatment for sore nipples in breastfeeding mothers?

    <p>Lanolin</p> Signup and view all the answers

    Epinephrine is derived from which neurotransmitter?

    <p>Norepinephrine</p> Signup and view all the answers

    Which statement accurately describes enzymes?

    <p>They accelerate reactions without being used up.</p> Signup and view all the answers

    Which neurotransmitter is known to be involved in mood and appetite regulation?

    <p>Serotonin</p> Signup and view all the answers

    What characterizes the polar basic side chains of certain amino acids?

    <p>They contain multiple amino groups and are positively charged</p> Signup and view all the answers

    What kind of substances do enzymes influence primarily?

    <p>Biological systems</p> Signup and view all the answers

    What class of amino acids includes those that give rise to glucose?

    <p>Glucogenic amino acids</p> Signup and view all the answers

    What is a common feature of waxes regarding their melting points?

    <p>They have relatively low melting points.</p> Signup and view all the answers

    Which function do enzymes not perform in biochemical reactions?

    <p>Get consumed in the reaction</p> Signup and view all the answers

    What is the role of ribosomal RNA (rRNA) in protein synthesis?

    <p>It serves as a structural component of the ribosome.</p> Signup and view all the answers

    Which type of RNA is responsible for delivering amino acids to the ribosome?

    <p>Transfer RNA (tRNA)</p> Signup and view all the answers

    What process follows transcription in protein synthesis?

    <p>Translation</p> Signup and view all the answers

    What is the primary purpose of transcription in the central dogma of molecular biology?

    <p>To read and carry genetic messages out of the nucleus.</p> Signup and view all the answers

    Which statement correctly describes the relationship between replication, transcription, and translation?

    <p>Replication makes copies of DNA, while transcription converts it to RNA.</p> Signup and view all the answers

    Which of the following is NOT a type of RNA involved in protein synthesis?

    <p>Peptide RNA (pRNA)</p> Signup and view all the answers

    Why is ribosomal RNA (rRNA) considered the most abundant type of RNA?

    <p>It is a crucial structural component of ribosomes.</p> Signup and view all the answers

    What type of complex is formed when an uncompetitive inhibitor binds to an enzyme?

    <p>Non-covalent complex</p> Signup and view all the answers

    What is a frameshift mutation primarily caused by?

    <p>Addition or loss of DNA bases</p> Signup and view all the answers

    What is the hallmark of a suicide inhibitor?

    <p>It permanently inactivates the enzyme.</p> Signup and view all the answers

    Which type of mutation involves the reversal of a segment within a chromosome?

    <p>Inversion</p> Signup and view all the answers

    Which factor primarily distinguishes competitive inhibitors from uncompetitive inhibitors?

    <p>The need for substrate presence</p> Signup and view all the answers

    What role do metal ions play in enzyme functionality?

    <p>They stabilize enzyme structure.</p> Signup and view all the answers

    What is the primary purpose of the polymerase chain reaction (PCR)?

    <p>To amplify specific DNA regions</p> Signup and view all the answers

    Which characteristic defines irreversible inhibitors?

    <p>They create covalent bonds with enzymes.</p> Signup and view all the answers

    What characterizes the deletion mutation?

    <p>Loss of a chromosomal segment</p> Signup and view all the answers

    What is the first step in the polymerase chain reaction process?

    <p>Denaturation of the template DNA</p> Signup and view all the answers

    What results from a frameshift mutation?

    <p>A nonfunctional or improperly functioning protein</p> Signup and view all the answers

    Which type of lipids are primarily responsible for energy storage?

    <p>Triacylglycerols</p> Signup and view all the answers

    What type of mutation involves moving a segment from one chromosome to a nonhomologous chromosome?

    <p>Translocation</p> Signup and view all the answers

    Which stage follows the annealing of primers in PCR?

    <p>Extension of the new DNA strands</p> Signup and view all the answers

    What role do prostaglandins play in the body?

    <p>Promote platelet aggregation</p> Signup and view all the answers

    Why is aspirin contraindicated in cases of dengue fever?

    <p>It may cause gastrointestinal bleeding</p> Signup and view all the answers

    What type of fatty acids are referred to as HUFA?

    <p>Higher unsaturated fatty acids</p> Signup and view all the answers

    What is the primary effect of thromboxanes?

    <p>Promote platelet aggregation</p> Signup and view all the answers

    What is a characteristic feature of trans fatty acids?

    <p>They pack more densely due to their structure</p> Signup and view all the answers

    Which of the following is NOT a precursor of eicosanoids?

    <p>Beta-linolenic acid</p> Signup and view all the answers

    Which leukotriene is known to increase vascular permeability and bronchoconstriction?

    <p>LTC4</p> Signup and view all the answers

    What is the structural characteristic of prostaglandins?

    <p>They contain three conjugated double bonds</p> Signup and view all the answers

    What is the primary biochemical impact of increased gastric secretion when prostaglandins are inhibited?

    <p>Decreased mucosal protection</p> Signup and view all the answers

    Which specific function do leukotrienes serve in the body?

    <p>Increase vascular permeability</p> Signup and view all the answers

    What is the definition of a holoenzyme?

    <p>An enzyme that consists of an apoenzyme and a cofactor</p> Signup and view all the answers

    Which of the following describes a metalloenzyme?

    <p>An enzyme that requires metal ions for its activity</p> Signup and view all the answers

    How does a catalyst function in a chemical reaction?

    <p>It lowers the activation energy required</p> Signup and view all the answers

    What is the primary role of coenzymes in enzymatic reactions?

    <p>To act as organic molecules derived from vitamins</p> Signup and view all the answers

    What is a substrate in the context of enzymatic reactions?

    <p>The reactant that is activated by the enzyme</p> Signup and view all the answers

    What distinguishes low-density lipoproteins (LDLs) from high-density lipoproteins (HDLs)?

    <p>LDLs are associated with higher cholesterol levels than HDLs</p> Signup and view all the answers

    Which statement accurately describes statins?

    <p>They are a class of drugs that lower cholesterol</p> Signup and view all the answers

    What is the main component of a prosthetic group in enzymes?

    <p>An organic molecule attached to the enzyme</p> Signup and view all the answers

    Which statement about metal ions in enzymes is accurate?

    <p>They enhance enzyme activity by increasing affinity for substrates</p> Signup and view all the answers

    What type of mutation results from the addition or loss of DNA bases that changes a gene’s reading frame?

    <p>Frameshift mutation</p> Signup and view all the answers

    Which type of mutation reverses a segment within a chromosome?

    <p>Inversion</p> Signup and view all the answers

    What is the first step in the polymerase chain reaction (PCR) process?

    <p>Denaturation of the template</p> Signup and view all the answers

    What type of lipid is primarily used for energy storage?

    <p>Triacylglycerols</p> Signup and view all the answers

    Which mutation is characterized by the removal of a chromosomal segment?

    <p>Deletion</p> Signup and view all the answers

    During PCR, what follows the annealing of primers?

    <p>Extension of new DNA strands</p> Signup and view all the answers

    Which bile salt contains glycine as its alipathic group?

    <p>Glycocholate</p> Signup and view all the answers

    What type of fats are predominantly saturated and solid at room temperature?

    <p>Fats</p> Signup and view all the answers

    What is the main type of mutation where nonhomologous chromosomes exchange fragments?

    <p>Reciprocal translocation</p> Signup and view all the answers

    Which of the following is a chemical reaction of triacylglycerols?

    <p>Hydrolysis</p> Signup and view all the answers

    What effect does the presence of double bonds generally have on fatty acids?

    <p>Lowers melting point</p> Signup and view all the answers

    What is a characteristic property of waxes in biological systems?

    <p>Hydrophobic</p> Signup and view all the answers

    What is the effect of increasing chain length on the melting temperature of unsaturated fatty acids?

    <p>It increases the melting temperature.</p> Signup and view all the answers

    Which type of fatty acid contains only one double bond in its structure?

    <p>Monounsaturated fatty acid</p> Signup and view all the answers

    What is the characteristic melting temperature of stearic acid?

    <p>69.9 °C</p> Signup and view all the answers

    How does unsaturation in fatty acids affect their intermolecular attraction?

    <p>It decreases intermolecular attraction.</p> Signup and view all the answers

    What classification does lauric acid fall under in terms of chain length?

    <p>Medium chain</p> Signup and view all the answers

    What happens to the melting point of fatty acids with increased saturation?

    <p>The melting point increases.</p> Signup and view all the answers

    What primarily influences the melting temperature of fatty acids?

    <p>The degree of saturation and chain length.</p> Signup and view all the answers

    Which statement correctly describes the molecular behavior of saturated fatty acids?

    <p>They form ordered structures and enhance intermolecular interaction.</p> Signup and view all the answers

    What type of fatty acids can animals not synthesize at the methyl end?

    <p>n-3 fatty acids</p> Signup and view all the answers

    Which animals require long-chain 20 and 22 carbon fatty acids in their diet?

    <p>Carnivores</p> Signup and view all the answers

    What is the primary role of prostaglandins in the body?

    <p>Enhancing inflammation responses</p> Signup and view all the answers

    Which of the following fatty acids is typically shorter and has lower melting points due to its double bonds?

    <p>Cis fatty acids</p> Signup and view all the answers

    Which of the following statements accurately describes glycolipids?

    <p>They consist of a fatty acid, sphingosine, and a carbohydrate.</p> Signup and view all the answers

    What is a characteristic effect of increased carbon chain length in fatty acids?

    <p>Higher melting point</p> Signup and view all the answers

    Which type of fatty acid is described as water insoluble?

    <p>Butyric acid</p> Signup and view all the answers

    What constitutes the parent structure of phospholipids?

    <p>Phosphatidic acid</p> Signup and view all the answers

    What physiological processes are influenced by the saturation of fatty acids?

    <p>Pain and inflammation management</p> Signup and view all the answers

    Why do animals require n-6 and n-3 fatty acids in their diets?

    <p>They cannot synthesize them</p> Signup and view all the answers

    What characteristic must a lipid have in order to form a cell membrane?

    <p>A polar and a nonpolar portion</p> Signup and view all the answers

    What effect do double bonds have on the melting point of fatty acids?

    <p>Decrease melting point</p> Signup and view all the answers

    Which component is often found in sphingophospholipids?

    <p>Fatty acids</p> Signup and view all the answers

    What consequences occur when aspirin is taken during fever?

    <p>Reduces prostaglandin production</p> Signup and view all the answers

    How do ceramide derivatives primarily function in the body?

    <p>As structural components in membranes</p> Signup and view all the answers

    Which component is a crucial feature of a phosphoglyceride?

    <p>Phosphatidic acid backbone</p> Signup and view all the answers

    What type of lipid is used to anchor blood type carbohydrates into the membranes of red blood cells?

    <p>Glycolipids</p> Signup and view all the answers

    What is the role of recognition sites created by certain lipids on cell surfaces?

    <p>Facilitate communication between cells</p> Signup and view all the answers

    Study Notes

    DNA vs RNA

    • DNA is found in the cell nucleus
    • DNA stores and transfers genetic information
    • DNA is passed from existing cells to new cells
    • RNA occurs in all parts of a cell
    • RNA's primary function is protein synthesis

    Purines vs Pyrimidines

    • There are five nitrogenous bases in total
    • Purines are double ring structures
    • Pyrimidines are single ring structures
    • If married, you'll say GA (Purines)
    • If single, you’ll CUT the relationship (Pyrimidines)

    Nucleoside formation

    • The nitrogenous base is connected to C1
    • C2 differentiates the sugar from H and OH
    • C5 is where the phosphate is located

    Structural characteristics of DNA

    • DNA is made of two polynucleotides running anti-parallel
    • One strand runs from 5' to 3' with the other strand running 3' to 5'
    • The sugar-phosphate backbone is on the outside
    • The hydrophobic bases are on the inside

    Base Pairing

    • A purine always pairs with a pyrimidine
    • A pairs with T and G pairs with C
    • This pairing is called complementary base pairing

    DNA Replication

    • Helicase unwinds the DNA and separates the strands
    • Primase anneals RNA primers
    • Polymerase III copies each strand
    • Polymerase I replaces the primers with DNA nucleotides
    • Ligase seals everything up

    Transcription

    • The process of copying a segment of DNA into RNA
    • DNA segments that produce messenger RNA encode proteins

    RNA in Protein Synthesis

    • Ribosomal RNA (rRNA) makes up the ribosome
    • Transfer RNA (tRNA) carries amino acids to the ribosome
    • Messenger RNA (mRNA) carries information to the ribosome, specifying the amino acid sequence of a protein

    Translation

    • mRNA is translated into protein
    • A sequence of three mRNA nucleotides codes for a specific amino acid
    • The order of codons determines the order of amino acids in a polypeptide chain

    Mutations

    • A change in the usual DNA sequence at a particular gene locus
    • Mutations can be harmful, beneficial, or neutral

    Point Mutation

    • A change in a single DNA base pair
    • Silence mutation - causes no change in the activity of the protein
    • Missense mutation - substitution of one amino acid for another in a protein
    • Nonsense mutation - results in a shortened protein

    Frameshift Mutation

    • The addition or loss of a DNA base changes a gene's reading frame
    • Results in a nonfunctional protein

    Central Dogma

    • Replication: Creation of identical DNA copies
    • Transcription: Genetic messages are read and carried out of the nucleus to the ribosomes for protein synthesis
    • Translation: Genetic messages are decoded to create proteins

    Lipid

    • A lipid is an organic compound that is insoluble in water but soluble in non-polar organic solvents
    • Lipids are classified based on solubility, not on functional groups
    • They are classified into: energy-storage lipids, membrane lipids, emulsification lipids, chemical messenger lipids, protective-coating lipids

    Fatty Acids

    • Structural components of lipids
    • Members of the carboxylic acid family
    • A hydrocarbon chain with a terminal carboxyl group
    • Saturated fatty acids: solid at room temp
    • Unsaturated fatty acids: liquid at room temp

    Essential fatty acids (EFA)

    • Animals cannot insert double bonds at the methyl end of the fatty acid molecule, at n-6 and n-3
    • The animals need n-6 and n-3 fatty acids in their diet

    Prostaglandins

    • A 20-carbon fatty-acid derivative with a cyclopentane ring and oxygen-containing functional groups
    • Involved in many physiological processes, including body temperature regulation, gastric juice secretion, mucus production, smooth muscle contraction & enhancing inflammatory responses

    Thromboxanes

    • 20-carbon fatty-acid derivative with a cyclic ether ring and oxygen- containing functional groups
    • Promotes platelet aggregation, contributing to blood clot formation & reducing blood flow, to the site of the clot

    Leukotrienes

    • 20-carbon fatty-acid derivative containing three conjugated double bonds and hydroxyl groups
    • Promotes inflammation, leukocyte aggregation & vascular permeability. Also contributes to allergic & hypersensitivity responses

    Simple Glycerides

    • Formed by the esterification of glycerol and fatty acids.
    • The primary function is energy storage (in the form of fat: triglycerides).

    Triacylglycerol

    • The major fat storage molecule
    • A triacylglycerol is formed from one glycerol and three fatty acids.
    • Energy yield from 9 cal/g is higher when compared to carbs or proteins
    • Compact form as it does not accompany water

    Naming a Triacylglycerol

    • A mixed triacylglycerol contains different fatty acids.
    • A simple triacylglycerol contains the same fatty acid

    Phospholipids

    • Contain a phosphate group
    • Frequently contain nitrogenous bases
    • Structural lipids mainly in membranes

    Sphingolipids

    • Parent structure = sphingosine, an 18-carbon molecule
    • Functions as recognition sites on cell surfaces & in the plasma membrane of neurons
    • Glycerophospholipids and sphingophospholipids are frequently found in cell membranes

    Cholesterol

    • Major & most known steroid in the body
    • Has 4 rings (cyclopentanoperhydropenanthrine)
    • A precursor of other steroids including bile acids & sex hormones

    Hormones from the adrenal cortex

    • Cortisol: dominant glucocorticoid in humans.
    • Important in stress adaptation & affects on blood pressure & Nat uptake
    • Aldosterone: promotes blood pressure & fluid volume & Increases Nat uptake

    Sex hormones

    • Testosterone is the male sex hormone
    • Estradiol is the main female sex hormone. Both responsible for secondary sex characteristics.

    Protein structural organization

    • Primary Structure: Linear sequence of amino acids linked by peptide bonds
    • Secondary Structure: Local folding patterns of the polypeptide chain (e.g., alpha helix, beta pleated sheet)
    • Tertiary Structure: Overall 3D shape of the polypeptide chain
    • Quaternary Structure: Structure of proteins that have more than one polypeptide chain

    Protein misfolding

    • Abnormal three-dimensional protein structure, deviating from its native conformation
    • Implicated in several diseases

    Amino acids and protein organization

    • Amino acids are the building blocks of proteins. Proteins are polymers of amino acids linked together through peptide bonds. There are about 700 amino acids found in nature, but only 20 are used in proteins.
    • The side chains of amino acids dictate properties
    • Proteins can be essential or nonessential
    • Amino acids determine protein properties

    Isoelectric Point

    • The pH at which an amino acid solution has no net charge
    • Reliant on the number of protons/charges of an amino acid

    Sterochemistry of Amino Acids

    • Mirror image pairs of amino acids are designated L and D and are called enantiomers.
    • Proteins are assembled from L-amino acids.

    Classification of Amino Acid - Side Chain

    • Amino acids are classified based on the polarity of their side chains (Non-polar, polar neutral, polar acidic or polar basic).

    Classification of Enzyme

    • Oxidoreductases: Catalyze oxidation-reduction reactions involving the transfer of electrons or hydrogen atoms
    • Transferases: Catalyze the transfer of a functional group from one molecule to another
    • Hydrolases: Catalyze the hydrolysis of a chemical bond by the addition of water
    • Lyases: Catalyze the cleavage of a chemical bond by means other than hydrolysis or oxidation
    • Isomerases: Catalyze the isomerization of a molecule (structural rearrangement)
    • Ligases: Join two molecules together, using energy input (often from ATP hydrolysis)

    Kinetics of Enzyme-Catalyzed Reactions

    • Enzyme-catalyzed reactions are often second-order reactions (velocity changes with substrate concentration).
    • Vmax represents the maximum velocity of an enzymatic reaction.
    • Km represents the substrate concentration at which half the enzyme active sites are occupied.
    • Enzymes and substrates bind to increase reaction rate; affinity affects Km.

    Enzyme Inhibition

    • Competitive inhibition: Inhibitor competes with the substrate for binding.
    • Uncompetitive inhibition: The inhibitor can bind only to the enzyme-substrate complex.
    • Suicide/Irreversible inhibition: Inhibitor binds to the enzyme and forms a permanent or covalent bond, inactivating the enzyme.

    Factors affecting Enzyme activity

    • Temperature
    • pH
    • Substrate concentration
    • Enzyme concentration
    • Presence of inhibitors or activators
    • Salt concentration

    Important Metabolite Tests

    • Test for proteins (e.g., Biuret test, Reduced sulfur test)
    • Tests for lipids (e.g., solubility and emulsification tests)
    • Test for reducing sugars (e.g., Benedict's test)
    • Test for unsaturation (e.g., bromine test)

    Acrolein Test

    • To determine the presence of glycerine in a fat. A positive result is indicated by a pungent odor.

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