Biochemistry - Protein and Carbohydrates Quiz
45 Questions
5 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What condition is associated with protein malnutrition and results in negative nitrogen balance?

  • Marasmus
  • Pellegra
  • Kwashiorkor (correct)
  • Cachexia

Which specialized product is synthesized from glycine that is essential for muscle energy storage?

  • Creatine (correct)
  • Hemoglobin
  • Glutathione
  • Collagen

What is the consequence of a deficiency in phenylalanine hydroxylase?

  • Phenylketonuria (PKU) (correct)
  • Skeletal abnormalities
  • Disruption of amino acid absorption
  • Tyrosine excess

Which of the following is a neurotransmitter synthesized from glutamic acid?

<p>GABA (B)</p> Signup and view all the answers

Which of the following products is synthesized from methionine and serves as a methyl donor?

<p>SAM (S-adenosyl methionine) (B)</p> Signup and view all the answers

What structure characterizes L-sugars?

<p>Hydroxyl group on the left side of the penultimate carbon atom (D)</p> Signup and view all the answers

Which of the following is an example of a ketotetrose?

<p>D-erythrulose (D)</p> Signup and view all the answers

Which classification does not accurately describe aldoses?

<p>Aldotetroses (C2) (C)</p> Signup and view all the answers

What type of isomerism do aldose-ketose pairs illustrate?

<p>Functional group isomerism (D)</p> Signup and view all the answers

Which monosaccharide is a component of RNA?

<p>D-ribose (A)</p> Signup and view all the answers

Which statement about D-glucose is false?

<p>It is exclusive to animal cells. (C)</p> Signup and view all the answers

Which of the following is a type of pentose?

<p>D-ribulose (D)</p> Signup and view all the answers

What is true about structural isomers?

<p>They have the same molecular formula but different structural formulas (C)</p> Signup and view all the answers

Which of the following amino acids is considered essential?

<p>Lysine (B)</p> Signup and view all the answers

What characterizes semi-essential or half-essential amino acids?

<p>They are only produced in the body during specific conditions. (C)</p> Signup and view all the answers

Which of the following proteins is considered to have a high biological value?

<p>Milk protein (C)</p> Signup and view all the answers

Which of the following statements is true regarding hydrophilic amino acids?

<p>They contain O or N atoms in their side chains. (A)</p> Signup and view all the answers

What type of nitrogen balance is observed when nitrogen loss exceeds nitrogen incorporation?

<p>Negative nitrogen balance (D)</p> Signup and view all the answers

Which of the following amino acids is classified as hydrophobic?

<p>Isoleucine (A)</p> Signup and view all the answers

What is the main role of hydrophobic amino acids in proteins?

<p>To be located in the interior of the protein, away from water. (C)</p> Signup and view all the answers

Which of the following amino acids has a negatively charged side chain at physiological pH?

<p>Glutamic acid (D)</p> Signup and view all the answers

What product is formed when glucose undergoes oxidation?

<p>Glucuronic acid (A)</p> Signup and view all the answers

Which of the following is a sugar alcohol derived from glucose?

<p>Sorbitol (C)</p> Signup and view all the answers

What type of monosaccharide derivative is formed when a hydroxyl group is replaced by a hydrogen atom?

<p>Deoxysugar (B)</p> Signup and view all the answers

Which of the following is a significant component of riboflavin?

<p>Ribitol (A)</p> Signup and view all the answers

Which sugar derivative contains an amino group replacing a hydroxyl group?

<p>Glucosamine (B)</p> Signup and view all the answers

Which type of ester is formed from the hydroxyl groups of monosaccharides?

<p>Phosphate esters (C)</p> Signup and view all the answers

What characterizes glycosides?

<p>Condensation of the anomeric carbon with non-carbohydrate compounds (B)</p> Signup and view all the answers

What is the role of aminosugars in biology?

<p>They contribute to glycosaminoglycans and are found in antibiotics (B)</p> Signup and view all the answers

What is the primary role of glycosaminoglycans (GAGs) in the extracellular matrix?

<p>To produce a gel-like matrix (B)</p> Signup and view all the answers

Which glycosaminoglycan is recognized for its role in wound repair?

<p>Hyaluronic acid (A)</p> Signup and view all the answers

Which of the following GAGs is known for maintaining corneal transparency?

<p>Keratan sulfate (C)</p> Signup and view all the answers

How do glycosaminoglycans (GAGs) contribute to the compressibility of cartilage?

<p>By creating a complex structure with various GAGs (B)</p> Signup and view all the answers

Which GAG is classified as a sulfate-containing heteropolysaccharide?

<p>Chondroitin sulfate (C)</p> Signup and view all the answers

What function do heparan sulfate proteoglycans have in the cellular context?

<p>They are crucial for cell-cell interactions (C)</p> Signup and view all the answers

Which property of GAGs allows them to attract water molecules?

<p>Highly polar structure (C)</p> Signup and view all the answers

What is one of the functions of heparin in the bloodstream?

<p>Preventing thrombus formation (D)</p> Signup and view all the answers

What is a primary characteristic of cis fatty acids?

<p>They commonly occur in nature. (C)</p> Signup and view all the answers

Which of the following is classified as an essential fatty acid?

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

What happens as a result of deficiency in essential fatty acids?

<p>Impaired growth in infants (A)</p> Signup and view all the answers

Which physical state do saturated fatty acids typically have at room temperature?

<p>Solid (A)</p> Signup and view all the answers

What type of lipids are phospholipids?

<p>Complex lipids (D)</p> Signup and view all the answers

What is the structural arrangement of trans fatty acids?

<p>Hydrogens on opposite sides of the double bond (B)</p> Signup and view all the answers

Which fatty acids are primarily derived from dietary sources related to PUFA?

<p>Linolenic and linoleic acids (B)</p> Signup and view all the answers

What are TAGs composed of?

<p>Three fatty acids and glycerol (A)</p> Signup and view all the answers

Flashcards

Negative Nitrogen Balance

A state where nitrogen loss exceeds incorporation, often associated with protein malnutrition, dietary deficiencies, starvation, uncontrolled diabetes, and infection.

Glycine Specialized Products

Glycine is used to create creatine (energy storage), collagen (connective tissue), hemoglobin, purine bases (adenine, guanine), and glutathione (antioxidant).

Methionine Specialized Product (SAM)

Methionine, a crucial part of SAM, is a methyl donor and plays a key role in epinephrine, choline, and creatine production.

Glutamic Acid Specialized Product (GABA)

Glutamic acid synthesizes γ-aminobutyric acid (GABA), a neurotransmitter that acts as an inhibitor in the central nervous system (CNS).

Signup and view all the flashcards

Phenylalanine Specialized Product

Phenylalanine is a precursor to the synthesis of tyrosine.

Signup and view all the flashcards

Phenylketonuria (PKU)

An inborn error of phenylalanine metabolism caused by phenylalanine hydroxylase deficiency, resulting in phenylalanine accumulation and potential severe developmental issues.

Signup and view all the flashcards

Phenylalanine Accumulation

Excess phenylalanine as a result of the inability to process it, leading to phenylpyruvic, phenyllactic, and phenylacetic acid buildup.

Signup and view all the flashcards

PKU Signs

Untreated PKU leads to developmental delays/retardation, autistic-like symptoms, motor control loss, pale skin, and light hair.

Signup and view all the flashcards

PKU Treatment

A restricted phenylalanine diet is crucial to manage phenylalanine levels and support healthy development.

Signup and view all the flashcards

Essential Amino Acids

Amino acids the body cannot produce and must be obtained through diet. Crucial for growth and protein synthesis.

Signup and view all the flashcards

Valine

An essential amino acid that plays a vital role in building proteins.

Signup and view all the flashcards

Leucine

An essential amino acid that is crucial for protein synthesis and muscle growth.

Signup and view all the flashcards

Isoleucine

An essential amino acid important in metabolism and providing energy to the body's cells.

Signup and view all the flashcards

Threonine

An essential amino acid needed for protein synthesis and the immune system.

Signup and view all the flashcards

Methionine

An essential amino acid important in metabolism and cellular function.

Signup and view all the flashcards

Lysine

An essential amino acid needed for protein synthesis and collagen production.

Signup and view all the flashcards

Phenylalanine

An essential amino acid needed for protein synthesis and the creation of other important molecules.

Signup and view all the flashcards

Tryptophan

An essential amino acid needed for protein synthesis and the production of serotonin and niacin.

Signup and view all the flashcards

Histidine

An essential amino acid important for growth and in various bodily functions.

Signup and view all the flashcards

Semi-essential Amino Acids

Amino acids produced by the body in sufficient quantities for adults but not growing individuals.

Signup and view all the flashcards

Non-essential Amino Acids

Amino acids produced by the body in sufficient quantities for both adults and growing individuals.

Signup and view all the flashcards

High Biological Value Proteins

Proteins containing all essential amino acids; generally considered to be the most nutritious.

Signup and view all the flashcards

Low Biological Value Proteins

Proteins lacking one or more essential amino acids; less nutritious than high biological value proteins.

Signup and view all the flashcards

Hydrophobic Amino Acids

Amino acids that repel water; tend to cluster together in the interior of proteins.

Signup and view all the flashcards

Hydrophilic Amino Acids

Amino acids that attract water; tend to cluster on the surface of proteins.

Signup and view all the flashcards

Nitrogen Balance

The equilibrium between nitrogen intake and nitrogen excretion in the body.

Signup and view all the flashcards

Negative Nitrogen Balance

Nitrogen loss exceeds nitrogen intake.

Signup and view all the flashcards

Positive Nitrogen Balance

Nitrogen intake exceeds nitrogen loss.

Signup and view all the flashcards

Uronic acids

Monosaccharides where the primary alcohol group is oxidized.

Signup and view all the flashcards

Glucuronic acid

Oxidized form of glucose, a uronic acid.

Signup and view all the flashcards

Sugar alcohols

Sugars with a reduced carbonyl group to an alcohol group.

Signup and view all the flashcards

Sorbitol

Sugar alcohol form of glucose.

Signup and view all the flashcards

Glycerol

Alcohol of glyceraldehyde/dihydroxyacetone, component of lipids.

Signup and view all the flashcards

Ribitol

Sugar alcohol form of ribose, part of vitamin B2.

Signup and view all the flashcards

Deoxysugars

Sugars with an -OH replaced by -H.

Signup and view all the flashcards

2-deoxy β-D-ribofuranose

Deoxysugar found in DNA's structure.

Signup and view all the flashcards

Aminosugars

Sugars with an amino group (NH2) replacing an -OH group.

Signup and view all the flashcards

Glycosides

Condensation products from sugar's anomeric carbon and non-carbohydrate compound.

Signup and view all the flashcards

Phosphate esters

Ester formed by hydroxyl groups on monosaccharides and phosphoric acid.

Signup and view all the flashcards

GAGs location

GAGs are primarily found in the extracellular matrix (ECM) and ground substance, associated with other extracellular proteins.

Signup and view all the flashcards

GAG chemical nature

GAGs are heteropolysaccharides composed of carbohydrate chains.

Signup and view all the flashcards

Hyaluronic acid

A sulfate-free GAG crucial for wound repair and providing cushioning.

Signup and view all the flashcards

GAGs and ECM function

GAGs form a gel-like matrix in the ECM providing shock absorption, lubrication, and structural support.

Signup and view all the flashcards

Aggrecan

A cartilage component with a complex structure containing multiple types of GAGs, impacting compressibility.

Signup and view all the flashcards

Keratan sulfate

GAG that contributes to corneal transparency and is important for healthy eyes.

Signup and view all the flashcards

Dermatan sulfate

GAG impacting the sclera's shape.

Signup and view all the flashcards

Heparin function

An anticoagulant preventing clot formation and activating antithrombin, inactivating coagulation factors (e.g., IX, XI).

Signup and view all the flashcards

Heparan sulfate

GAG important for cell-cell interactions and cell membrane receptors.

Signup and view all the flashcards

GAG water attraction

GAGs are highly polar molecules and draw water, creating a hydrated gel.

Signup and view all the flashcards

Hydrated gel properties

Hydrated gel provides flexibility, lubrication, and compressibility to the ECM.

Signup and view all the flashcards

L-sugars

Monosaccharides where the hydroxyl group on the penultimate carbon atom is on the left side.

Signup and view all the flashcards

D-sugars

Most naturally occurring monosaccharides have the hydroxyl group on the right side of the penultimate carbon atom.

Signup and view all the flashcards

Aldoses

Sugars containing an aldehyde functional group (CHO).

Signup and view all the flashcards

Aldotrioses

Aldoses with 3 carbon atoms.

Signup and view all the flashcards

Aldotetroses

Aldoses with 4 carbon atoms.

Signup and view all the flashcards

Aldopentoses

Aldoses with 5 carbon atoms.

Signup and view all the flashcards

Aldohexoses

Aldoses with 6 carbon atoms.

Signup and view all the flashcards

Ketoses

Sugars containing a ketone functional group.

Signup and view all the flashcards

Ketotrioses

Ketoses with 3 carbon atoms.

Signup and view all the flashcards

Isomers

Molecules with the same molecular formula but different structural or steric formulas.

Signup and view all the flashcards

Stereoisomers

Molecules with the same molecular formula and sequence of bonded atoms, but different 3D arrangements.

Signup and view all the flashcards

Aldose-Keto isomers

Monosaccharides with same molecular formulas but different functional groups.

Signup and view all the flashcards

Triose

Monosaccharide with 3 carbon atoms

Signup and view all the flashcards

Tetrose

Monosaccharide with 4 carbon atoms

Signup and view all the flashcards

Pentose

Monosaccharide with 5 carbon atoms

Signup and view all the flashcards

Hexose

Monosaccharide with 6 carbon atoms

Signup and view all the flashcards

Unsaturated Fatty Acids

Fatty acids with one or more double bonds in their hydrocarbon chain.

Signup and view all the flashcards

Cis Isomer

Hydrogen atoms on the same side of the carbon-carbon double bond.

Signup and view all the flashcards

Trans Isomer

Hydrogen atoms on opposite sides of the carbon-carbon double bond.

Signup and view all the flashcards

Essential Fatty Acids

Fatty acids our body can't make, so we must get them from food.

Signup and view all the flashcards

Linoleic Acid

An essential fatty acid.

Signup and view all the flashcards

Linolenic Acid

An essential fatty acid.

Signup and view all the flashcards

Arachidonic Acid

An essential fatty acid.

Signup and view all the flashcards

Triacylglycerol (TAG)

Storage form of fatty acids in adipose tissue.

Signup and view all the flashcards

Solubility of Fatty Acids

Fatty acids are insoluble in water but soluble in fat solvents.

Signup and view all the flashcards

Saturated Fatty Acids

Fatty acids with no double bonds and are solid at room temperature.

Signup and view all the flashcards

Unsaturated Long Chain Fatty Acids

Fatty acids with one or more double bonds and are liquids at room temperature.

Signup and view all the flashcards

Phospholipids

Lipids containing fatty acids, an alcohol, and a phosphate group.

Signup and view all the flashcards

Glycolipids

Lipids containing fatty acids, sphingosine, and carbohydrates.

Signup and view all the flashcards

Study Notes

Protein Chemistry

  • Proteins are composed of a large number of amino acids linked together by peptide bonds.
  • Proteins have amphoteric properties.
  • Each protein has an isoelectric point (pI) at which the number of ionized negatively charged carboxyl groups equals the number of positively charged amino groups.
  • Proteins are classified as simple, compound, or derived.
  • Simple proteins are hydrolyzed to amino acids only. Example: Albumin and globulin in plasma and milk. Scleroproteins like keratin (skin), collagen (tendons, ligaments, connective tissue, bone, cartilage)
  • Compound proteins are hydrolyzed to amino acids and a prosthetic group. Examples of compound proteins:
    • Phosphoproteins: Milk casein
    • Lipoproteins: The form of lipid in blood circulation. Blood group antigens on red blood cells. Immunoglobulins (antibodies) in plasma. Proteoglycans attached to glycosaminoglycans in extracellular matrix of connective tissues. Metalloproteins containing iron (Fe).
  • Derived proteins are produced by hydrolysis of simple or conjugated lipids. Examples: fatty acids, alcohols, steroids, carotenoids, fat-soluble vitamins (A, D, E, K). -Hemoglobin is a tetramer composed of four polypeptide chains, two identical alpha (α) chains and two identical beta (β) chains -Myoglobin is an oxygen storage protein found mainly in muscle tissue. Composed of a single polypeptide chain.

Protein Structure

  • Primary structure: The sequence of amino acids in a polypeptide chain. -Not affected by denaturation.
  • Secondary structure: Coiling or folding of the primary structure. Common types are alpha-helices and beta-sheets. -Held together by hydrogen bonds.
  • Tertiary structure: The three-dimensional arrangement of the polypeptide chain. -Determined by hydrophobic interactions, electrostatic forces (ionic bonds), and hydrogen bonds. -Either fibrous (insoluble in water) or globular (soluble in water).
  • Quaternary structure: The arrangement of multiple polypeptide chains in a protein. -Held together by non-covalent interactions, and is affected by denaturation.
  • Examples: hemoglobin, myoglobin.

Denaturation

  • Denaturation is the change in the native state of a protein. -Rupture of weak bonds without altering primary structure. Common causes: - Physical: high pressure, high temperature, ionizing radiation (X-ray, UV), shaking (agitation), repeated freezing and thawing - Chemical: strong acids, strong bases, alcohol, heavy metals (like Pb2+, Ag2+, and Cu2+ etc), organic solvents, urea
    • It can lead to a change in physical, chemical, and biological properties of proteins.
    • It can be reversible in some conditions.

Molecular Chaperones

  • Unfolded proteins are toxic to the cell due to their tendency to form large aggregates.
  • Machinery for safe protein folding is critical to cell function.
  • Chaperones are a class of proteins that facilitate successful protein folding. An energy-consuming process.

Amino Acids

  • Building blocks of proteins.
  • Classified as neutral, acidic, and basic based on their chemical properties.
    • Hydroxyl containing amino acids: Serine, Theronine
    • Sulphate containing amino acids: Cysteine, Methionine
    • Neutral amino acids: Glycine, Alanine
    • Acidic amino acids: Aspartic acid, Glutamic acid
    • Basic amino acids: Lysine, arginine, histidine
  • Classified as hydrophilic or hydrophobic according to their interaction with water. -Hydrophobic: Phenylalanine, Tyrosine, Tryptophan, Valine, leucine and isoleucine. -Hydrophilic: Contain O or N atoms, some charged at physiological pH. Acidic amino acids (aspartic and glutamic acids) are negatively charged. Basic amino acids (lysine, arginine, and histidine) are positively charged.

Protein functions

  • Proteins perform diverse roles; Examples are in:
    • Transport, like hemoglobin which carries oxygen.
    • Support, as in collagen.
    • Enzymes, like those that speed up metabolic reactions.
    • Hormones, like insulin which regulates blood sugar levels.

Amino Acid Conversion to Specialized Products

  • Amino acids serve as precursors for specialized products in the body. Examples include:
    • Glycogen and Cellulose.
    • Neurotransmitters like melatonin and serotonin.
    • Hormones (e.g., thyroid hormones, epinephrine). -Pigments (e.g., melanin).
  • The conversion of amino acids into specialized products can be affected by genetic and nutritional factors.

Nitrogen Balance

  • Nitrogen balance is a measure of the balance between the amount of nitrogen consumed and excreted. -Negative nitrogen balance: Nitrogen loss exceeds absorption, occurs during conditions like starvation, malnutrition, and injury.
  • Positive nitrogen balance: Nitrogen absorption exceeds excretion, occurs during growth and pregnancy.

Carbohydrates

  • Chemical nature: polyhydroxyalcohols with a functional aldehyde or keto group (e.g., glucose, fructose).
  • Classification: Monosaccharides (single sugar units), Disaccharides (two sugar units), Oligosaccharides (a few sugar units), Polysaccharides (>10 sugar units). Examples include:
    • Glucose, Fructose, Galactose, Maltose, Sucrose, Lactose, Starch, Glycogen, Cellulose.
  • Biomedical importance: Provide energy, storage, structure (cell membranes), and communication.
  • Monosaccharide classification by number of carbon atoms, functional groups (aldose/ketose).
  • Important derivatives: Sugar acids (e.g., glucuronic acid), sugar alcohols (e.g., sorbitol), deoxy-sugars (e.g., deoxyribose), aminosugars (e.g., glucosamine).
  • Glycosides and ester formation.

Lipids

  • Definition: Organic compounds that are esters of fatty acids or substances associated with them. Insoluble in water but soluble in fat solvents.
    • Classification: Simple, compound (or conjugated), and derived.
  • Fatty acids: Classified as saturated (no double bonds), monounsaturated (one double bond), and polyunsaturated (more than one double bond) -Examples: Stearic acid, oleic acid, linoleic acid.
  • Simple Lipids:
    • Triacylglycerols: Esters of three fatty acids and glycerol, stored in adipose tissue.
    • Waxes: Esters of fatty acids and long chain alcohols.
  • Compound Lipids:
    • Phospholipids: Lipids containing a phosphoric acid residue; Important for cell membranes and emulsifying factors.
      • Glycerophospholipids and sphingomyelin.
    • Glycolipids: Lipids containing carbohydrates; Important components of cell membranes.
    • Proteolipids: Lipids containing proteins; Water insoluble.
  • Derived lipids: Products of hydrolysis of simple or compound lipids. -Fatty acids, alcohols, steroids (e.g., cholesterol, bile acids), carotenoids, fat-soluble vitamins (A, D, E, K).

Cholesterol

  • An important steroid in animals.
  • Can be converted into bile acids, bile salts, or steroid hormones.
  • Can be oxidized to 7-dehydrocholesterol converts to vitamin D3 by ultraviolet (UV) light.
  • Functions include precursor of steroid hormones, component of cell membranes, precursor of vitamin D.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Protein Chemistry Lectures (PDF)

Description

Test your knowledge on key concepts of biochemistry related to protein malnutrition, neurotransmitters, and sugar classifications. This quiz covers various biochemical compounds and their significance in the human body. Challenge yourself to understand the intricate relationships between amino acids and carbohydrates.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser