Biochemical Aspects of Enzyme Inhibition
41 Questions
0 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

Which type of amino acid is arginine classified as?

  • Semi-essential (correct)
  • Tertiary
  • Essential
  • Non-essential

What is the correct classification of a peptide consisting of three amino acids?

  • Polypeptide
  • Tripeptide (correct)
  • Oligopeptide
  • Dipeptide

Which amino acid serves as the amino (N) terminal in the given peptide Val–Cys–Asp–Leu–Ala–Arg–Phe–Glu–Trp?

  • Cys
  • Leu
  • Trp
  • Val (correct)

Which of the following carbohydrate types is classified as a homopolysaccharide?

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

Which amino acid is identified as the carboxyl (C) terminal in the peptide chain Val–Cys–Asp–Leu–Ala–Arg–Phe–Glu–Trp?

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

What is a primary consequence of protein energy malnutrition due to lack of essential dietary requirements?

<p>Muscle atrophy (D)</p> Signup and view all the answers

Which mechanism describes how heat stroke can lead to brain damage?

<p>Denaturation of proteins in sensitive tissues (A)</p> Signup and view all the answers

What role does lowering body temperature play in organ cryopreservation?

<p>Minimizes tissue damage by slowing metabolic processes (A)</p> Signup and view all the answers

How does penicillin affect bacterial cells?

<p>It irreversibly inhibits transpeptidase (D)</p> Signup and view all the answers

What is the consequence of inappropriate activation of digestive enzymes in the pancreas?

<p>Digestive enzymes attacking pancreatic tissue (D)</p> Signup and view all the answers

What is the impact of organophosphorus compounds on the nervous system?

<p>Inhibit acetylcholine breakdown (A)</p> Signup and view all the answers

How does carbon monoxide affect cellular respiration?

<p>Binds to cytochrome c oxidase (A)</p> Signup and view all the answers

What is the role of glutathione in the body?

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

What does a low Km value indicate about an enzyme's affinity for its substrate?

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

Which of the following factors does NOT affect enzyme activity?

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

What effect does bradykinin have on blood pressure?

<p>Decreases blood pressure (B)</p> Signup and view all the answers

Which mechanism leads to proto-oncogene activation through gene amplification?

<p>Overproduction of the gene (B)</p> Signup and view all the answers

What is the effect of marked changes in pH on enzyme activity?

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

Which of the following correctly describes the relationship between Km and Vmax?

<p>Km is independent of Vmax (A)</p> Signup and view all the answers

How does vasopressin affect blood pressure?

<p>Raises blood pressure via fluid retention (D)</p> Signup and view all the answers

The optimum pH range for most enzymes falls between which values?

<p>5-9 (D)</p> Signup and view all the answers

Which amino acids are classified as polar uncharged?

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

What role do chaperones play in protein folding?

<p>They assist in the proper folding of proteins. (C)</p> Signup and view all the answers

Which amino acids are considered essential and must be supplied in the diet?

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

Which group of amino acids contain sulfur in their side chains?

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

How are ionic bonds formed in proteins?

<p>Between positively and negatively charged amino acids (D)</p> Signup and view all the answers

Which amino acid is classified as an imino acid?

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

Which enzyme is primarily associated with liver function and is important for diagnosing liver diseases?

<p>Gamma-Glutamyl Transferase (GGT) (C)</p> Signup and view all the answers

What type of amino acid has side chains that cannot react with water?

<p>Non-polar amino acids (D)</p> Signup and view all the answers

What distinguishes isoenzymes from each other?

<p>They differ in amino acid sequence and tissue distribution. (C)</p> Signup and view all the answers

Which amino acid is involved in the formation of covalent disulfide bonds?

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

What is the role of streptokinase in medical treatment?

<p>To dissolve blood clots in myocardial infarction. (D)</p> Signup and view all the answers

What characteristic do aromatic amino acids share?

<p>They absorb UV light at 280 nm (A)</p> Signup and view all the answers

Which of the following enzymes is associated with muscle damage?

<p>Creatine Kinase (CK) (C)</p> Signup and view all the answers

Which type of amino acids are found on the surface of proteins and can react with water?

<p>Polar charged amino acids (B)</p> Signup and view all the answers

Which enzyme is used therapeutically for patients with acute lymphoblastic leukemia?

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

Which enzyme can indicate both heart attacks and liver diseases?

<p>Aspartate Aminotransferase (AST) (B)</p> Signup and view all the answers

Which isoenzyme is not associated with the brain?

<p>Creatine Kinase (CK3) (D)</p> Signup and view all the answers

What is the primary substrate that asparaginase acts upon?

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

Which enzyme is most commonly used to assess pancreatic disorders?

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

Which factor does NOT typically influence the optimal conditions of isoenzymes?

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

Flashcards

Muscle atrophy in malnutrition

Proteins and essential nutrients, like amino acids and fatty acids, are not consumed enough, leading to protein energy malnutrition.

Heat stroke

High heat denatures proteins in the brain, disrupting cell function and communication. This can lead to organ damage and loss of consciousness.

Organ cryopreservation

Lowering body temperature slows down enzyme activity, minimizing metabolic processes and reducing tissue damage during organ preservation. This helps keep organs viable for transplantation.

Penicillin as an antibiotic

Penicillin prevents bacterial cell wall synthesis by irreversibly inhibiting transpeptidase. This weakens the cell wall and eventually causes the bacteria to lyse and die.

Signup and view all the flashcards

Aspirin as an analgesic and antithrombotic

Aspirin permanently blocks the COX enzyme, which reduces inflammation, pain, and blood clotting by inhibiting prostaglandin and thromboxane production.

Signup and view all the flashcards

Biochemical basis of pancreatitis

Pancreas produces digestive enzymes as inactive forms (zymogens) that are activated in the intestine. If activated prematurely within the pancreas, these enzymes can digest the pancreas itself, causing inflammation and damage.

Signup and view all the flashcards

Organophosphorus poisons

Organophosphorus compounds, like insecticides, permanently inhibit acetylcholinesterase, preventing the breakdown of acetylcholine. This leads to continuous muscle stimulation, potentially causing paralysis and death.

Signup and view all the flashcards

Glutathione

A tripeptide that acts as an antioxidant, protecting cells from damage caused by free radicals.

Signup and view all the flashcards

Endorphin

A natural pain reliever produced by the body, similar to morphine.

Signup and view all the flashcards

Bradykinin

A substance that causes blood vessels to dilate, leading to a decrease in blood pressure.

Signup and view all the flashcards

Vasopressin

A hormone that causes blood vessels to constrict, raising blood pressure. It also regulates water balance by increasing water reabsorption in the kidneys.

Signup and view all the flashcards

Point mutation

A change in a single nucleotide within a gene's DNA sequence.

Signup and view all the flashcards

Gene amplification

An increase in the number of copies of a gene, leading to increased protein production.

Signup and view all the flashcards

Chromosomal translocation

A change in the structure of a chromosome, often resulting in the fusion of genes from different chromosomes.

Signup and view all the flashcards

Insertional mutagenesis

The insertion of a gene into a new location on a chromosome, often disrupting the function of the existing gene.

Signup and view all the flashcards

Michaelis Constant (Km)

The substrate concentration at which the reaction rate is half the maximum velocity. It represents the enzyme's affinity for its substrate.

Signup and view all the flashcards

What are amino acids?

Amino acids are the building blocks of proteins. They contain an alpha carbon bound to an amino group, a carboxyl group, a hydrogen atom, and a unique side chain or R group.

Signup and view all the flashcards

What is a peptide bond?

A peptide bond is a type of covalent bond that joins amino acids together to form proteins. It forms through a condensation reaction between the carboxyl group of one amino acid and the amino group of another, releasing a molecule of water.

Signup and view all the flashcards

What are the N-terminus and C-terminus of a peptide?

The amino terminal (N-terminal) is the end of a peptide chain with a free amino group. The carboxyl terminal (C-terminal) is the end of the chain with a free carboxyl group.

Signup and view all the flashcards

What are monosaccharides?

Monosaccharides are simple sugars that cannot be broken down further. They are the basic building blocks of carbohydrates. Examples include glucose, fructose, and galactose.

Signup and view all the flashcards

What are disaccharides?

Disaccharides are formed by the combination of two monosaccharides linked by a glycosidic bond. Examples include lactose, sucrose, and maltose.

Signup and view all the flashcards

Isoenzymes

Enzymes that catalyze the same chemical reaction but are different molecular forms synthesized by different tissues. They share the same reaction, substrate, and coenzymes, but differ in amino acid sequence, tissue distribution, optimal conditions, and electrophoretic mobility.

Signup and view all the flashcards

Alkaline Phosphatase (ALP)

A liver enzyme elevated in liver diseases, bone disorders, and bile duct obstructions.

Signup and view all the flashcards

Gamma-Glutamyl Transferase (GGT)

A liver enzyme elevated in liver disease, alcohol abuse, and bile duct obstruction.

Signup and view all the flashcards

Alanine Aminotransferase (ALT)

A liver enzyme elevated in liver diseases.

Signup and view all the flashcards

Aspartate Aminotransferase (AST)

A liver enzyme elevated in liver diseases.

Signup and view all the flashcards

Creatine Kinase (CK)

An enzyme elevated in muscle damage, injury, and heart attacks.

Signup and view all the flashcards

Lactate Dehydrogenase (LDH)

An enzyme elevated in heart attack, liver disease, and hemolytic anemia.

Signup and view all the flashcards

Amylase & Lipase

Enzymes elevated in pancreatitis and pancreatic disorders.

Signup and view all the flashcards

Streptokinase

An enzyme used therapeutically to dissolve blood clots in patients with conditions like myocardial infarction (heart attack).

Signup and view all the flashcards

Asparaginase

An enzyme used to treat acute lymphoblastic leukemia (ALL).

Signup and view all the flashcards

What are Chaperones?

Chaperones are proteins that assist in the proper folding of other proteins, preventing misfolding and aggregation. They are essential for maintaining cellular function by ensuring proteins fold into their correct conformations.

Signup and view all the flashcards

What is Disulfide Isomerase?

Disulfide isomerase is an enzyme that catalyzes the formation and breakage of disulfide bonds between cysteine residues in proteins. These bonds play a crucial role in protein folding and stability.

Signup and view all the flashcards

What is Cis-Trans Isomerase?

Cis-trans isomerase helps to interconvert cis and trans isomers of proline residues within proteins, impacting their conformation and function.

Signup and view all the flashcards

What are Aliphatic Amino Acids?

Aliphatic amino acids have side chains consisting only of carbon and hydrogen atoms. They are typically non-polar and hydrophobic. Examples include glycine, alanine, valine, leucine, and isoleucine.

Signup and view all the flashcards

What are Amino Acids with OH Groups?

Amino acids with hydroxyl (OH) groups in their side chains are classified as polar and hydrophilic. They are often found on the surface of proteins, interacting with water molecules. Serine and threonine fall into this category.

Signup and view all the flashcards

What is Cysteine and its Role?

Cysteine is an amino acid with a sulfur-containing side chain. It plays a crucial role in protein structure by forming disulfide bonds, which help stabilize the protein's shape.

Signup and view all the flashcards

What are Acidic Amino Acids?

Aspartic acid and glutamic acid are acidic amino acids with negatively charged side chains at physiological pH. They interact with positively charged amino acids to form ionic bonds, contributing to protein structure.

Signup and view all the flashcards

What are Amide Derivatives?

Asparagine and glutamine are amide derivatives of aspartic acid and glutamic acid, respectively. They have polar, uncharged side chains and are often involved in hydrogen bonding within proteins.

Signup and view all the flashcards

What are Basic Amino Acids?

Arginine, lysine, and histidine are basic amino acids with positively charged side chains at physiological pH. They interact with acidic amino acids to form ionic bonds, contributing to protein structure.

Signup and view all the flashcards

What are Aromatic Amino Acids?

Aromatic amino acids have ring structures in their side chains, including phenylalanine, tyrosine, and tryptophan. These amino acids are often found buried within the protein's core due to their hydrophobic nature.

Signup and view all the flashcards

Study Notes

Biochemical Aspects - Question 1 Comparison

  • Reversible - Competitive Inhibition: Inhibitor structure similar to substrate, binds to active site. E+I <-> EI. Km is increased, Vmax is not affected. Lineweaver-Burk plot: same y-intercept, x-intercept shifts left. Reversal by increasing substrate concentration. Examples include sulfonamides and methotrexate.

  • Reversible - Non-competitive Inhibition: Inhibitor structure not similar to substrate, binds to allosteric site. E+I <-> EI, ES+I <-> ESI. Vmax is decreased, Km is not affected. Lineweaver-Burk plot: same x-intercept, y-intercept shifts up. Reversal not by increasing substrate concentration, possibly by dialysis. Examples include dicumarol.

Michaelis-Menten Kinetics and Lineweaver-Burk Plots

  • Michaelis-Menten kinetics describes enzyme-catalyzed reactions.
  • Lineweaver-Burk plots are graphical representations of Michaelis-Menten data.
  • The Lineweaver-Burk plot uses the reciprocal of the reaction rates.
  • The y-intercept of the Lineweaver-Burk plot is 1/Vmax.
  • The x-intercept of the Lineweaver-Burk plot is -1/Km.
  • Competitive and non-competitive inhibitors shift the x and or y-intercepts of the lineweaver-burk plot differently

Other Concepts

  • Absolute Enzyme Specificity: Enzymes act on a single substrate. Example: glucokinase acts only on glucose, urease acts only on urea.

  • Relative Enzyme Specificity: Enzymes act on structurally similar substrates but not limited to one. Example: hexokinase acts on hexoses including glucose, fructose, mannose

  • Functional Plasma Enzymes: Enzymes in the blood with known functions, often synthesized by the liver to maintain health. Examples include clotting factors, lipoproteins.

  • Non-Functional Plasma Enzymes: Enzymes in the blood without known functions. Examples include ALT, AST, CK, LDH.

  • Enzyme Specificity: Each enzyme works optimally on a certain type of substrate, also known as either absolute or relative specificity

  • Glycogen and Starch: Both are branched polysaccharides with thousands of glucose units, important for glucose storage. Glycogen: in humans and animals. Starch: in plants.

  • Alcohol, Fats and Waxes: Alcohol: glycerol & fatty acid ester. Fats: ester of fatty acids and glycerol. Waxes: high molecular weight fatty acid and mono-hydroxyl alcohol

  • Protein Structure: The first structure, primary structure of a protein, is a linear sequence of amino acids. The secondary structure (secondary protein structure) is composed of alpha helices or beta sheets, while Tertiary structure (3D structure) is the three-dimensional shape formed by interactions between the secondary structures. The quaternary structure (quaternary protein structure) is the three dimensional shape formed by interactions between multiple polypeptide chains.

  • Enzyme Regulation Types: Short-term: Allosteric regulation, reversible covalent modification, proteolytic cleavage, and compartmentalization. Long-term: enzyme synthesis or degradation and enzyme compartmentalization

  • Monomers and Polymers: Monomers are small, single units, like glucose, amino acids, and nucleotides. Polymers are large molecules made up of repeating monomers, such as starch or proteins.

  • OH-containing and Sulfur-containing Amino Acids: OH-containing: serine, threonine. Sulfur-containing: cysteine, methionine

  • High & Low Biological Value Proteins: High biological value proteins (animal-based): contain all essential amino acids needed to build and maintain body proteins. Low biological Value proteins are plant-based (plant-based): deficient in one or more essential amino acids

  • PCR (Polymerase Chain Reaction): A technique to amplify DNA sequences from a small amount of DNA, useful for diagnosis of diseases.

  • Gene Cloning: A process to produce many copies of a DNA fragment.

  • Somatic and Germline Gene Therapy: Somatic gene therapy alters genes in non-reproductive cells and isn't passed on. Germline therapy alters genes in reproductive cells and can be inherited.

  • Cell Cycle Regulation: Regulation of cell growth and division: Strict regulatory mechanisms ensure balanced cell growth; however, deregulation is associated with several health problems such as uncontrolled cell growth in cancer

  • Enzyme Regulation: Long term: enzyme synthesis or degradation and enzyme compartmentalization. Short term: allosteric regulation, reversible covalent modification, proteolytic cleavage and compartmentalization.

Studying That Suits You

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

Quiz Team

Related Documents

MBI 105-106 Medical Biochemistry Biochemical Aspects PDF

Description

Explore the biochemical principles behind reversible enzyme inhibition, focusing on competitive and non-competitive mechanisms. This quiz covers essential concepts such as Km, Vmax, and Lineweaver-Burk plots. Test your understanding of Michaelis-Menten kinetics and the implications for enzyme behavior.

More Like This

Michaelis-Menton Equation and Product Inhibition
11 questions

Michaelis-Menton Equation and Product Inhibition

AccommodativeEquation avatar
AccommodativeEquation
Enzymatic Reaction Kinetics
13 questions

Enzymatic Reaction Kinetics

GaloreRhodium8872 avatar
GaloreRhodium8872
Enzyme Kinetics and Inhibition
13 questions

Enzyme Kinetics and Inhibition

ViewableUnakite7414 avatar
ViewableUnakite7414
Enzyme Kinetics Quiz
5 questions

Enzyme Kinetics Quiz

UnlimitedRadiance3949 avatar
UnlimitedRadiance3949
Use Quizgecko on...
Browser
Open
Browser
Browser