BC1_memrizz_mc_Tue Jul 02 2024.pdf

Memrizz BC1 Multiple Choice Questions What is an element? a) Pure substances with specific physical/chemical properties. b) Molecules made of two or more atoms. c) Substances that can be broken down into simpler components. d) Elements that are composed of multiple sub...

Memrizz BC1 Multiple Choice Questions What is an element? a) Pure substances with specific physical/chemical properties. b) Molecules made of two or more atoms. c) Substances that can be broken down into simpler components. d) Elements that are composed of multiple substances. Correct answer: Pure substances with specific physical/chemical properties. What is the smallest unit of matter that retains the chemical properties of an element? a) Molecule. b) Atom. c) Isomer. d) Carbohydrate. Correct answer: Atom. What are intramolecular forces responsible for? a) Holding molecules together. b) Breaking down elements. c) Holding atoms within a molecule together. d) Creating new molecules. Correct answer: Holding atoms within a molecule together. What do monomers and polymers refer to? a) Monomers are large molecules made up of several atoms. b) Monomers are single molecules capable of polymerization; Polymers are made of many monomers linked together. c) Polymers are individual atoms linked together. d) Polymers are always smaller than monomers. Correct answer: Monomers are single molecules capable of polymerization; Polymers are made of many monomers linked together. What do carbohydrates consist of? a) Nitrogen, carbon, and hydrogen atoms. b) Only carbon and oxygen atoms. c) Carbon, hydrogen, and oxygen atoms. d) Carbon, hydrogen, and chlorine atoms. Correct answer: Carbon, hydrogen, and oxygen atoms. Which monosaccharide has a 5-carbon structure? a) Fructose. b) Glucose. c) Ribose. d) Cellulose. Correct answer: Ribose. What defines isomers? a) Having the same chemical formula but different atom arrangements. b) Being identical in all properties. c) Having different chemical formulas. d) Always existing as monomers. Correct answer: Having the same chemical formula but different atom arrangements. What is the composition of disaccharides? a) A single monomer. b) Two monosaccharides linked together. c) Three or more monosaccharides linked together. d) Several polymers combined. Correct answer: Two monosaccharides linked together. What is the function of glycogen in humans? a) Structural component b) Energy storage c) Cellular communication d) Antibody production Correct answer: Energy storage Which type of bonding is found in cellulose? a) Covalent bonding b) Ionic bonding c) Hydrogen bonding d) Beta bonding Correct answer: Beta bonding What is the role of chitin in fungi cell walls and insect exoskeleton? a) Structural component b) Energy storage c) Receptor function d) Nucleic acid synthesis Correct answer: Structural component What elements are present in proteins? a) Potassium, sulfur, iron, calcium b) Hydrogen, oxygen, phosphorus, sulfur c) Carbon, hydrogen, oxygen, and nitrogen d) Nitrogen, magnesium, carbon, chlorine Correct answer: Carbon, hydrogen, oxygen, and nitrogen What do amino acids combine to form? a) Polypeptides b) Nucleic acids c) Carbohydrates d) Lipids Correct answer: Polypeptides What is the primary structure of a protein? a) Three-dimensional structure b) Sequence of amino acids c) Hydrophobic core d) Disulfide bonds formation Correct answer: Sequence of amino acids What is the key feature of secondary protein structure? a) Formation of peptide bonds b) Intermolecular forces due to hydrogen bonding c) Disulfide bonds involvement d) Creation of hydrophobic spaces Correct answer: Intermolecular forces due to hydrogen bonding What does the primary structure of a protein refer to? a) Sequence of amino acids b) Hydrogen bonding between R-groups c) Formation of alpha helices d) Creation of hydrophobic spaces Correct answer: Sequence of amino acids What type of forces contribute to the secondary structure of a protein? a) Covalent bonding between R-groups b) Intermolecular forces due to hydrogen bonding between the polypeptide backbone c) Hydrophobic interactions d) Ionic interactions between amino acids Correct answer: Intermolecular forces due to hydrogen bonding between the polypeptide backbone What structures can be formed in the secondary structure of a protein? a) Disulfide bonds b) Tertiary structures c) Alpha helices or beta helices d) Quaternary structures Correct answer: Alpha helices or beta helices In the tertiary structure of a protein, what contributes to the creation of hydrophobic or hydrophilic spaces? a) Covalent bonding between amino acids b) Ionic forces between alpha helices c) Interactions between R-groups d) Formation of disulfide bonds Correct answer: Interactions between R-groups Which type of bonding leads to the formation of Disulfide bonds in the tertiary structure of a protein? a) Hydrogen bonding between R-groups b) Covalent bonding between the R-groups of two cysteine amino acids c) Ionic interactions between amino acids d) Assembly of multiple polypeptide chains Correct answer: Covalent bonding between the R-groups of two cysteine amino acids What does the quaternary structure of a protein involve? a) Three-dimensional structure resulting from R-group interactions b) Formation of alpha helices c) Creation of hydrophobic or hydrophilic spaces d) Assembly of multiple polypeptide chains to form a single protein Correct answer: Assembly of multiple polypeptide chains to form a single protein What is the primary function of glycogen in humans? a) Structural component b) Cell wall formation c) Energy storage d) Catalyst for reactions Correct answer: Energy storage Which type of bonding is present in glycogen? a) Alpha bonded b) Beta bonded c) Ionic bonded d) Covalent bonded Correct answer: Alpha bonded What is the main role of cellulose in plant cell walls? a) Energy storage b) Acting as enzymes c) Structural component d) Aiding in cell communication Correct answer: Structural component How are the strands of cellulose packed within cell walls? a) Rigidly in parallel b) Loosely intertwined c) Randomly distributed d) Tightly coiled Correct answer: Rigidly in parallel In which organisms is chitin a structural component of cell walls and exoskeletons? a) Plants and animals b) Fungi and insects c) Bacteria and viruses d) Algae and protozoa Correct answer: Fungi and insects What are the components of conjugated proteins? a) Only amino acids b) Amino acids + other components c) Nucleic acids d) Carbohydrates Correct answer: Amino acids + other components What describes protein denaturation? a) Increase in protein function b) Loss of protein function and higher order structures c) Enhanced protein folding d) Gaining new structures Correct answer: Loss of protein function and higher order structures Which protein structure remains unaffected during denaturation? a) Tertiary structure b) Quaternary structure c) Primary structure d) Structural conformation Correct answer: Primary structure What are common reasons for protein denaturation? a) High or low temperatures, pH changes, salt concentrations b) Increased pressure, light exposure, humidity levels c) Chemical bonding, electrical currents, pressure changes d) Enzymatic reactions, genetic mutations, mechanical stress Correct answer: High or low temperatures, pH changes, salt concentrations What is the main function of enzymes in biological systems? a) Store amino acids b) Enhance structure of tissues c) Regulate physiological processes d) Act as biological catalysts Correct answer: Act as biological catalysts How do catalysts influence reaction rates? a) By increasing the activation energy b) By changing the equilibrium position c) By altering the reaction products d) By lowering the activation energy Correct answer: By lowering the activation energy What is the unstable intermediate state between reactants and products called? a) Equilibrium point b) Stable state c) Critical state d) Transition state Correct answer: Transition state What role do enzymes play in biochemical reactions? a) Enzymes inhibit all reactions in the body. b) Enzymes increase the activation energy of reactions. c) Enzymes have no impact on reaction rates. d) Enzymes act as biological catalysts by binding to substrates and converting them into products. Correct answer: Enzymes act as biological catalysts by binding to substrates and converting them into products. How do catalysts increase reaction rates? a) Catalysts increase the energy of the transition state. b) Catalysts reduce the energy of the substrates. c) Catalysts increase reaction rates by lowering the activation energy of a reaction. d) Catalysts have no effect on reaction rates. Correct answer: Catalysts increase reaction rates by lowering the activation energy of a reaction. What is the function of catalysts in a chemical reaction? a) Catalysts shift a chemical reaction to a different pathway. b) Catalysts increase the energy of the products. c) Catalysts have no role in a chemical reaction. d) Catalysts reduce the energy of the transition state. Correct answer: Catalysts reduce the energy of the transition state. What is the transition state in a chemical reaction? a) The stable state after the reaction is complete. b) The starting state before any reaction occurs. c) The transition state is the unstable intermediate between the reactants and the products. d) A state where reactants and products exist in equilibrium. Correct answer: The transition state is the unstable intermediate between the reactants and the products. What is the role of glycogen in biological systems? a) Structural component in plant cell walls b) Structural component in fungi cell walls and insect exoskeleton c) An enzyme aiding in substrate binding d) Energy storage for humans Correct answer: Energy storage for humans Which type of bond characterizes cellulose? a) Alpha bonded polysaccharide b) Beta bonded polysaccharide c) Van der Waals bonded polysaccharide d) Ionic bonded polysaccharide Correct answer: Beta bonded polysaccharide What is the structural role of cellulose in plant cell walls? a) Spherical arrangement throughout the cell wall b) Linear strands packed rigidly in parallel c) Helical structure binding to lipid bilayers d) Randomly intertwined fibers Correct answer: Linear strands packed rigidly in parallel Where is chitin found as a structural component? a) Animal muscle tissue b) Human red blood cells c) Plant chloroplasts d) Fungi cell walls and insect exoskeleton Correct answer: Fungi cell walls and insect exoskeleton What is the activation site in enzymes? a) Region where enzymes are produced b) Location where enzymes release products c) An area where enzymes store energy d) Specific location on the substrate where the enzyme binds Correct answer: Specific location on the substrate where the enzyme binds What is the term used to measure enzyme efficiency in substrate binding and conversion? a) Specificity Constant b) Activation Energy c) Enzyme Kinetics d) Transition State Correct answer: Specificity Constant Which theory describes how the active site of an enzyme changes to fit the substrate? a) Lock and Key Theory b) Allosteric Regulation Theory c) Induced Fit Theory d) Substrate Binding Model Correct answer: Induced Fit Theory What is a ribozyme? a) An RNA molecule acting as an enzyme b) An enzyme made up of only proteins c) An enzyme found in the cytoplasm d) A molecule that inhibits enzyme activity Correct answer: An RNA molecule acting as an enzyme What are cofactors in enzyme reactions? a) Non-protein molecules aiding enzyme reactions b) Proteins that degrade enzymes c) Substrates unable to bind to enzymes d) Inhibitors preventing enzyme activity Correct answer: Non-protein molecules aiding enzyme reactions What is the main difference between holoenzymes and apo-enzymes? a) Holoenzymes are enzymes bound to cofactors, while apo-enzymes are not. b) Holoenzymes are enzymes that degrade substrates, apo-enzymes are inactive forms c) Holoenzymes have metal ions as cofactors, apo-enzymes have vitamins d) Holoenzymes show induced fit theory, apo-enzymes exhibit lock and key model Correct answer: Holoenzymes are enzymes bound to cofactors, while apo-enzymes are not. How do competitive inhibitors affect enzyme action? a) Competitive inhibitor binds irreversibly to the enzyme active site b) Competitive inhibition leads to enzyme denaturation c) Competitive inhibitor competes with the substrate for active site binding; enzyme action rate can be increased by adding more substrate; Km increases/Vmax stays the same d) Km decreases due to competitive inhibition Correct answer: Competitive inhibitor competes with the substrate for active site binding; enzyme action rate can be increased by adding more substrate; Km increases/Vmax stays the same What are prosthetic groups and cofactors in relation to enzymes? a) Loosely associated with enzymes. b) Act as substrates for enzymes. c) Regulate enzyme concentrations. d) Tightly or covalently bound to enzymes. Correct answer: Tightly or covalently bound to enzymes. Why are protein enzymes susceptible to denaturation? a) Organic cofactors binding. b) Prosthetic groups involvement. c) Competitive inhibition interactions. d) Require optimal temperatures and pH for proper function. Correct answer: Require optimal temperatures and pH for proper function. How does competitive inhibition affect enzyme activity? a) Km decreases while Vmax increases. b) Km increases while Vmax remains the same. c) Both Km and Vmax decrease. d) Both Km and Vmax increase. Correct answer: Km increases while Vmax remains the same. When does noncompetitive inhibition occur? a) When substrate concentration decreases. b) When a noncompetitive inhibitor binds to the allosteric site of an enzyme. c) When enzyme concentration increases. d) When a competitive inhibitor binds directly to the active site. Correct answer: When a noncompetitive inhibitor binds to the allosteric site of an enzyme. What is the primary function of glycogen in humans? a) Energy storage b) Structural component c) Enzyme activation d) Cell signaling Correct answer: Energy storage How is glycogen classified in terms of bonding? a) Beta bonded polysaccharide b) Ionic bonded polysaccharide c) Alpha bonded polysaccharide d) Covalent bonded polysaccharide Correct answer: Alpha bonded polysaccharide Which biological structures does cellulose primarily contribute to? a) Animal cell membranes b) Fungal cell nuclei c) Insect exoskeletons d) Plant cell walls Correct answer: Plant cell walls How is cellulose classified in terms of bonding? a) Alpha bonded polysaccharide b) Covalent bonded polysaccharide c) Beta bonded polysaccharide d) Ionic bonded polysaccharide Correct answer: Beta bonded polysaccharide What is the structural arrangement of cellulose? a) Spherical clusters b) Linear strands packed rigidly in parallel c) Randomly arranged chains d) Helical coiling Correct answer: Linear strands packed rigidly in parallel In which biological structures does chitin primarily function? a) Plant cell walls b) Human muscle tissues c) Fungi cell walls and insect exoskeletons d) Bacterial cell membranes Correct answer: Fungi cell walls and insect exoskeletons What does the Michaelis Constant (Km) indicate in enzyme kinetics? a) Maximum reaction velocity b) Rate of reaction plateau c) Substrate concentration [X] at which velocity (V) is 50% of Vmax d) Effect of inhibitors on enzymes Correct answer: Substrate concentration [X] at which velocity (V) is 50% of Vmax When does saturation occur in an enzyme kinetics plot? a) When no substrate is present b) At the beginning of the reaction c) When all active sites are occupied d) During enzyme denaturation Correct answer: When all active sites are occupied What property of lipids makes them hydrophobic? a) Polar head groups b) High solubility in water c) Presence of phosphate groups d) Long hydrocarbon tails Correct answer: Long hydrocarbon tails What is the structural composition of a triacylglycerol molecule? a) Ribose backbone and 3 amino acids connected by peptide bonds b) Phosphate backbone and 3 nucleic acids connected by hydrogen bonds c) Glycerol backbone and 3 fatty acids connected by ester linkages d) Polysaccharide backbone and 3 proteins connected by disulfide bridges Correct answer: Glycerol backbone and 3 fatty acids connected by ester linkages Why do saturated fatty acids solidify at room temperature? a) Presence of kinks in the structure b) Lack of double bonds leads to tight packing c) High water content d) Strong ionic interactions Correct answer: Lack of double bonds leads to tight packing What characteristic of cis-unsaturated fatty acids prevents tight packing? a) Long hydrocarbon tails b) Kinks in the hydrocarbon tails c) Absence of double bonds d) Presence of phosphate groups Correct answer: Kinks in the hydrocarbon tails What defines monounsaturated fatty acids? a) Having no double bonds. b) Having three double bonds. c) Having one double bond. d) Having saturated hydrocarbon tails. Correct answer: Having one double bond. How are polyunsaturated fatty acids characterized? a) Having a single double bond. b) Having two or more double bonds. c) Having only saturated hydrocarbon tails. d) Containing a phosphate group. Correct answer: Having two or more double bonds. What distinguishes cis-unsaturated fatty acids? a) They have straight hydrocarbon tails. b) They contain a glycerol backbone. c) They are amphipathic. d) They have kinks that cause loose packing of hydrocarbon tails. Correct answer: They have kinks that cause loose packing of hydrocarbon tails. What is a characteristic of trans-unsaturated fatty acids? a) They have kinks causing loose packing. b) They are amphipathic in nature. c) They have straight hydrocarbon tails leading to tight packing. d) They contain a phosphate group. Correct answer: They have straight hydrocarbon tails leading to tight packing. What are phospholipids composed of? a) Cholesterol and two phosphate groups. b) Glycerol backbone, one phosphate group, and two fatty acids. c) Three phosphate groups and one fatty acid. d) One glycerol and three fatty acids. Correct answer: Glycerol backbone, one phosphate group, and two fatty acids. How do phospholipids arrange themselves due to their amphipathic nature? a) They form micelles in solution. b) They aggregate with cholesterol molecules. c) They spontaneously assemble into a lipid bilayer. d) They align in a single layer. Correct answer: They spontaneously assemble into a lipid bilayer. What makes the phosphate group of phospholipids polar and hydrophilic? a) Its nonpolar nature. b) Its polar nature. c) Its interaction with cholesterol. d) Its linear structure. Correct answer: Its polar nature. Why are the fatty acid tails of phospholipids hydrophobic? a) Due to their polar nature like the phosphate group. b) Because they are nonpolar. c) Because they have kinks in their structure. d) Because they contain multiple phosphate groups. Correct answer: Because they are nonpolar. What role does cholesterol play in cell membranes? a) It is an enzyme catalyst. b) It triggers apoptosis in cells. c) It is a crucial component. d) It promotes cell division. Correct answer: It is a crucial component. What is the main function of glycogen in humans? a) Energy storage for humans b) Structural component in plant cell walls c) Component of the cell membrane d) Transport lipid molecules in the bloodstream Correct answer: Energy storage for humans What type of bonding is found in glycogen? a) Beta bonded polysaccharide b) Covalent bonding c) Alpha bonded polysaccharide d) Hydrogen bonding Correct answer: Alpha bonded polysaccharide Which polysaccharide is a structural component in plant cell walls? a) Chitin b) Glycogen c) Cellulose d) Lipids Correct answer: Cellulose What type of bonding is found in cellulose? a) Alpha bonded polysaccharide b) Covalent bonding c) Hydrogen bonding d) Beta bonded polysaccharide Correct answer: Beta bonded polysaccharide What is characteristic of the linear strands of cellulose? a) Packed rigidly in parallel b) Spherical shape c) Helical structure d) Loosely arranged Correct answer: Packed rigidly in parallel Where is chitin a structural component? a) Plant cell walls b) Animal cell membranes c) Bacterial cell walls d) Fungi cell walls and insect exoskeleton Correct answer: Fungi cell walls and insect exoskeleton What is a characteristic of lipids in cell membranes? a) Highly charged b) Solid at room temperature c) Amphipathic nature d) Water-soluble Correct answer: Amphipathic nature Which lipid serves as a precursor to steroid hormones? a) Cholesterol b) Lipids c) Triglycerides d) Phospholipids Correct answer: Lipids What is a role of lipoproteins in the bloodstream? a) Transport lipid molecules b) Produce bile acids c) Store excess glucose d) Serve as structural components Correct answer: Transport lipid molecules What is the function of low-density lipoproteins (LDLs) in the body? a) Transport cholesterol to the liver b) Deliver cholesterol to peripheral tissues c) Promote bile production d) Reduce blood lipid levels Correct answer: Deliver cholesterol to peripheral tissues What is a characteristic of high-density lipoproteins (HDLs)? a) Transport cholesterol to the liver for bile production b) Deliver cholesterol to peripheral tissues c) Increase blood lipid levels d) Maintain high protein density Correct answer: Transport cholesterol to the liver for bile production What is a common use of waxes? a) Hydrophilic emulsifiers b) Water-soluble solvents c) Hydrophobic protective coatings d) Biodegradable packaging materials Correct answer: Hydrophobic protective coatings What is a defining feature of carotenoids? a) Aliphatic hydrocarbons only b) Contain conjugated double bonds and six-membered rings c) Linear chain structure d) Form hydrogen bonds with water Correct answer: Contain conjugated double bonds and six-membered rings What is the primary function of waxes? a) Serving as energy storage molecules b) Acting as hydrophobic protective coatings c) Functioning as enzymes d) Participating in cell signaling Correct answer: Acting as hydrophobic protective coatings How are waxes defined in biochemistry? a) Complex proteins with multiple peptide bonds b) Carbohydrates with glucose polymers c) Aromatic compounds with benzene rings d) Simple lipids with long fatty acids linked to monohydroxy alcohols via ester linkages Correct answer: Simple lipids with long fatty acids linked to monohydroxy alcohols via ester linkages What is the main function of carotenoids in biological systems? a) Facilitating cell communication b) Serving as energy storage molecules c) Acting primarily as pigments d) Contributing to ATP production Correct answer: Acting primarily as pigments How are carotenoids characterized in terms of structure? a) Proteins with helical structures b) Complex carbohydrates with branching chains c) Inorganic compounds with metallic bonds d) Lipid derivatives with long carbon chains, conjugated double bonds, and six-membered rings at each end Correct answer: Lipid derivatives with long carbon chains, conjugated double bonds, and six-membered rings at each end What elements make up nucleic acids? a) Carbon, hydrogen, oxygen, nitrogen, and phosphorus atoms b) Sodium, potassium, chloride, and calcium ions c) Iron, copper, zinc, and manganese atoms d) Silicon, sulfur, magnesium, and aluminum elements Correct answer: Carbon, hydrogen, oxygen, nitrogen, and phosphorus atoms What is the basic composition of nucleosides? a) A 5-carbon sugar and a nitrogenous base b) Amino acids and fatty acids c) Monosaccharides and disaccharides d) Phosphate groups and nucleic acid bases Correct answer: A 5-carbon sugar and a nitrogenous base What is the structural unit that nucleic acids are composed of? a) Polypeptide chains b) Glycogen polymers c) Steroid rings d) Nucleotide monomers Correct answer: Nucleotide monomers Which molecule serves as an energy storage for humans? a) Glycogen b) Cellulose c) Chitin d) Deoxyribose Sugars Correct answer: Glycogen What type of polysaccharide is cellulose? a) Alpha bonded b) Linear strands packed c) Beta bonded d) 2' carbon Correct answer: Beta bonded What structural component(s) does chitin contribute to? a) Plant cell walls b) DNA sugars c) Fungi cell walls and insect exoskeleton d) Ribose 5-Carbon Sugars Correct answer: Fungi cell walls and insect exoskeleton Which carbon in deoxyribose sugars contains a hydrogen? a) 2' carbon b) 5' carbon c) 3' carbon d) 4' carbon Correct answer: 2' carbon What functional group is present at the 2' carbon in ribose 5-carbon sugars? a) Phosphate group b) Methyl group c) Hydroxyl group d) Carbonyl group Correct answer: Hydroxyl group Which nucleotide is found in DNA but not in RNA? a) Uracil (U) b) Adenine (A) c) Thymine (T) d) Guanine (G) Correct answer: Thymine (T) What distinguishes purines from pyrimidines in structure? a) Purines have a hydroxyl group b) Pyrimidines contain thymine c) Purines are linear strands d) Purines consist of two rings; pyrimidines consist of one ring Correct answer: Purines consist of two rings; pyrimidines consist of one ring How are nucleotides joined along the sugar-phosphate backbone? a) By hydrogen bonds b) Through ester linkages c) By phosphodiester bonds d) Via disulfide bonds Correct answer: By phosphodiester bonds Where are nucleoside triphosphates added during nucleic acid polymerization? a) 5' end of the sugar-phosphate backbone b) 2' carbon of ribose sugars c) Phosphate group of nucleotides d) 3' end of the sugar-phosphate backbone Correct answer: 3' end of the sugar-phosphate backbone How are nucleotides connected in a phosphodiester bond? a) The nitrogenous base of one nucleotide binds to the sugar of another nucleotide. b) The adenine of one nucleotide pairs with thymine of another nucleotide. c) The 5' carbon of one nucleotide binds to the 5' carbon of another nucleotide. d) The phosphate group of one nucleotide is connected to the hydroxyl group of another nucleotide. Correct answer: The phosphate group of one nucleotide is connected to the hydroxyl group of another nucleotide. What makes up the sugar-phosphate backbone in nucleic acids? a) Hydrogen bonds between nucleotides. b) Covalent bonds between nitrogenous bases. c) Phosphodiester bonds linking nucleotides with a 5' end and a 3' end. d) Van der Waals forces between nucleotides. Correct answer: Phosphodiester bonds linking nucleotides with a 5' end and a 3' end. How does nucleic acid polymerization occur? a) Nucleotides are added to the 5' end of the sugar-phosphate backbone. b) Nucleoside triphosphates are added to the 3' end of the sugar-phosphate backbone. c) Nucleotides are randomly inserted in the DNA structure. d) Nucleotides form disulfide bonds to polymerize. Correct answer: Nucleoside triphosphates are added to the 3' end of the sugar-phosphate backbone. What is the structural configuration of DNA? a) DNA forms a single helix with random base pairing. b) DNA is circular with diverse base pairing. c) DNA forms an antiparallel double helix with complementary base pairing. d) DNA forms a parallel double helix with non-complementary base pairing. Correct answer: DNA forms an antiparallel double helix with complementary base pairing. How do adenine and thymine interact in DNA? a) Adenine forms covalent bonds with thymine. b) Adenine and thymine repel each other due to charge. c) Adenine forms 3 hydrogen bonds with thymine. d) Adenine forms 2 hydrogen bonds with thymine. Correct answer: Adenine forms 2 hydrogen bonds with thymine. What characterizes the structure of RNA? a) RNA is double-stranded and contains thymine. b) RNA forms a triplet helix structure with unique base pairing. c) RNA is circular and devoid of nitrogenous bases. d) RNA is single-stranded and contains uracil which binds to adenine. Correct answer: RNA is single-stranded and contains uracil which binds to adenine. Which statement is true according to modern cell theory? a) Cells can spontaneously generate from non-living matter. b) Cells emerge independently without division. c) Cells are formed by fusion of inorganic molecules. d) All cells originate from pre-existing cells through cell division. Correct answer: All cells originate from pre-existing cells through cell division. What is the primary role of Glycogen in humans? a) Structural component b) Catalyzing reactions c) Energy storage d) Information storage Correct answer: Energy storage How are the glucose units connected in Glycogen? a) Beta-bonded b) Alpha-bonded c) Covalently bonded d) Hydrogen-bonded Correct answer: Alpha-bonded Which type of polysaccharide is Cellulose? a) Beta-bonded b) Alpha-bonded c) Gamma-bonded d) Delta-bonded Correct answer: Beta-bonded What is the primary function of Cellulose in plant cell walls? a) Energy storage b) Information storage c) Structural component d) Enzyme catalysis Correct answer: Structural component How are the linear strands of Cellulose packed in plant cell walls? a) Rigidly in parallel b) Loosely in clusters c) Randomly in all directions d) Spirally around the nucleus Correct answer: Rigidly in parallel Where is Chitin primarily found as a structural component? a) Human muscles b) Plant stems c) Fish scales d) Fungi cell walls and insect exoskeletons Correct answer: Fungi cell walls and insect exoskeletons According to the Central Dogma of Genetics, what is the flow of genetic information? a) Proteins to RNA to DNA b) RNA to DNA to Proteins c) Proteins to DNA to RNA d) DNA to RNA to Proteins Correct answer: DNA to RNA to Proteins What is the primary role of RNA in the RNA World Hypothesis? a) Energy storage b) Dominated Earth's primordial soup before life c) Structural support d) Enzyme catalysis Correct answer: Dominated Earth's primordial soup before life In a combustion reaction, what are the primary products when a hydrocarbon reacts with oxygen? a) CH4 + O2 b) CO2 + H2O c) H2O + N2 d) CO + H2 Correct answer: CO2 + H2O What type of linkages are formed through a dehydration process in polysaccharides? a) Peptide linkages b) Glycosidic linkages c) Disulfide linkages d) Ester linkages Correct answer: Glycosidic linkages What do empirical formulas provide in a compound? a) The exact number of atoms in a compound b) The most-reduced whole number ratio of each atom c) The molecular weight of the compound d) The arrangement of atoms in the compound Correct answer: The most-reduced whole number ratio of each atom How are glycosidic linkages formed? a) Through the process of hydrolysis b) Through the process of dehydration c) Through the addition of oxygen atoms d) Through the process of polymerization Correct answer: Through the process of dehydration What is the function of cellulose in plant cells? a) Facilitates energy storage in plant cells b) Aids in protein synthesis in plant cells c) Acts as a neurotransmitter in plant cells d) Provides structure for plant cells Correct answer: Provides structure for plant cells What is the key characteristic of a dehydration/condensation reaction? a) Breakdown of glycosidic bonds between monosaccharides. b) Formation of a glycosidic bond between two monosaccharides. c) Addition of water to form monosaccharides. d) Formation of peptide bonds between amino acids. Correct answer: Formation of a glycosidic bond between two monosaccharides. How does a hydrolysis reaction differ from a dehydration reaction? a) Involves breaking a covalent bond by adding water. b) Forms a glycosidic bond between two monosaccharides. c) Occurs when water is removed to form a covalent bond. d) Breaks down glycosidic bonds without the addition of water. Correct answer: Involves breaking a covalent bond by adding water. Which monosaccharides make up sucrose? a) Galactose and Glucose. b) Glucose and Glucose. c) Fructose and Maltose. d) Glucose and Fructose. Correct answer: Glucose and Fructose. What is the main function of Starch in plants? a) Structural support in plant cell walls. b) Energy storage in plants. c) Facilitating cell-to-cell communication. d) Aiding in photosynthesis process. Correct answer: Energy storage in plants. Which type of bond is characteristic of Cellulose structure? a) Alpha bonded polysaccharides. b) Beta bonded polysaccharides. c) Glycosidic bonds between monosaccharides. d) Peptide bonds between amino acids. Correct answer: Beta bonded polysaccharides. What type of bonds contribute to the secondary structure of proteins? a) Covalent Bonds b) Ionic Bonds c) Van der Waals Forces d) Hydrogen Bonds Correct answer: Hydrogen Bonds What characteristic is exhibited by ribozymes? a) High Specificity Constant b) Denaturation Resistance c) Lower Activation Energy d) Allosteric Regulation Correct answer: Lower Activation Energy How is a highly efficient enzyme indicated? a) Low Substrate Affinity b) Unspecific Binding c) Slow Catalytic Rate d) High Specificity Constant Correct answer: High Specificity Constant What differentiates phospholipids from glycolipids? a) Hydrophobic Tail b) Phosphate Head Group c) Carbohydrate Group d) Cholesterol Molecule Correct answer: Carbohydrate Group How do cells adjust their membrane lipid content? a) By increasing cholesterol content b) By decreasing protein content c) By altering DNA sequence d) In response to external and internal changes Correct answer: In response to external and internal changes What occurs in a cell to increase membrane fluidity when temperature decreases? a) Decreasing protein synthesis b) Increasing hydrophobic interactions c) Raising the amount of unsaturated fatty acids d) Enhancing glycolipid production Correct answer: Raising the amount of unsaturated fatty acids How many hydrogen bonds are formed in AT base pairs in DNA? a) 2 H-bonds b) 1 H-bond c) 3 H-bonds d) 4 H-bonds Correct answer: 2 H-bonds How many hydrogen bonds are formed in CG base pairs in DNA? a) 1 H-bond b) 2 H-bonds c) 4 H-bonds d) 3 H-bonds Correct answer: 3 H-bonds What components make up a nucleotide? a) A 4-carbon sugar, a nitrogenous base, and a phosphate group. b) A 6-carbon sugar, a nitrogenous acid, and a phosphate molecule. c) A 5-carbon sugar, a nitrogenous base, and a phosphate group. d) A 3-nitrogen sugar, a basic base, and a phosphorous group. Correct answer: A 5-carbon sugar, a nitrogenous base, and a phosphate group. How do purines differ from pyrimidines? a) Purines have one ring, while pyrimidines have two rings. b) Purines have two rings, while pyrimidines have one ring. c) Purines contain thymine, while pyrimidines contain guanine. d) Pyrimidines contain uracil, while purines contain cytosine. Correct answer: Purines have two rings, while pyrimidines have one ring. What is the process of transcription? a) Synthesizing DNA from an RNA template. b) Synthesizing RNA from a DNA template. c) Creating proteins from RNA molecules. d) Breaking down DNA into its constituent nucleotides. Correct answer: Synthesizing RNA from a DNA template. What is the definition of translation? a) Synthesizing proteins from mRNA. b) Converting DNA into RNA molecules. c) Changing ribosomal RNA into transfer RNA. d) Duplicating the genetic code within DNA. Correct answer: Synthesizing proteins from mRNA. What does gene expression entail? a) Storing genetic material in DNA sequences. b) Using information from a gene to synthesize a functional gene product. c) Replicating DNA for cellular division. d) Rearranging genetic material during meiosis. Correct answer: Using information from a gene to synthesize a functional gene product.