Skip to main content
Back

BIOCHEM 212 LECTURE ELEVEN: Enzyme Regulation, Vitamins, and Serological Testing

Control buttons has been changed to "navigation" mode.
1/29

Terms in this set (29)

  • What is competitive enzyme inhibition?

    Competitive inhibition occurs when an inhibitor resembles the substrate and competes for the same active site on the enzyme.

  • How does noncompetitive inhibition affect enzyme activity?

    Noncompetitive inhibition involves an inhibitor binding to a separate site on the enzyme, changing the active site shape and preventing substrate binding.

  • What characterizes uncompetitive inhibition?

    Uncompetitive inhibition occurs when the inhibitor binds only to the enzyme-substrate complex, not to the free enzyme.

  • What is irreversible enzyme inhibition?

    Irreversible inhibition involves covalent modification of the enzyme, permanently inactivating it.

  • How does competitive inhibition affect Km and Vmax?

    Competitive inhibition increases Km (decreases affinity) but does not change Vmax.

  • How does noncompetitive inhibition affect Km and Vmax?

    Noncompetitive inhibition lowers Vmax but does not change Km.

  • How does uncompetitive inhibition affect Km and Vmax?

    Uncompetitive inhibition lowers both Km and Vmax by the same ratio.

  • What are the main types of enzyme regulation in metabolic pathways?

    Feedback control, allosteric control, covalent modification, genetic control, and zymogen activation.

  • What is allosteric regulation?

    Binding of a molecule at a site other than the active site that changes enzyme activity; can be positive (activator) or negative (inhibitor).

  • What is feedback control in enzyme regulation?

    A product of a metabolic pathway acts as an allosteric regulator of an enzyme earlier in the pathway, either inhibiting (negative) or enhancing (positive) its activity.

  • What is covalent modification in enzyme regulation?

    Addition or removal of chemical groups (e.g., phosphate) to amino acid residues, causing conformational changes that activate or deactivate enzymes.

  • What are zymogens?

    Inactive enzyme precursors that require cleavage of a protein segment to become active enzymes.

  • What is genetic control of enzyme activity?

    Regulation of enzyme levels by turning genes on or off, affecting enzyme synthesis and degradation.

  • Which vitamins are fat-soluble?

    Vitamins A, D, E, and K are fat-soluble and stored in the liver.

  • Which vitamins are water-soluble?

    Vitamin C and the B-complex vitamins (B1, B2, B3, B5, B6, B7, B9, B12) are water-soluble and not stored in the body.

  • Why are vitamins classified as fat-soluble or water-soluble?

    Based on their solubility: fat-soluble vitamins are hydrophobic and stored in fat tissues; water-soluble vitamins are hydrophilic and generally not stored.

  • What is a coenzyme?

    A small organic molecule derived from vitamins that binds to enzymes and is required for catalytic activity.

  • Which vitamins become coenzymes?

    Most water-soluble vitamins (B-complex and C) become coenzymes or coenzyme precursors.

  • Name the coenzyme derived from Vitamin B1 (Thiamine).

    Thiamine pyrophosphate (TPP), essential for carbohydrate metabolism and decarboxylation reactions.

  • What coenzymes are derived from Vitamin B2 (Riboflavin)?

    Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), involved in redox reactions.

  • What coenzymes are derived from Vitamin B3 (Niacin)?

    Nicotinamide adenine dinucleotide (NAD+/NADH) and NAD phosphate (NADP+/NADPH), involved in oxidation-reduction reactions.

  • What is the function of Vitamin B5 (Pantothenic acid) coenzyme?

    Coenzyme A, which carries acetyl groups into the TCA cycle.

  • What is the coenzyme form of Vitamin B6 (Pyridoxine) and its function?

    Pyridoxal phosphate (PLP), involved in amino acid metabolism and transamination reactions.

  • What is the coenzyme derived from Vitamin B7 (Biotin)?

    Biotin or biocytin, a carbon carrier in carbohydrate and lipid metabolism.

  • What is the coenzyme form of Vitamin B9 (Folic acid)?

    Tetrahydrofolate (THF), which carries one-carbon units for DNA synthesis and amino acid metabolism.

  • What coenzymes are derived from Vitamin B12 (Cobalamin)?

    Methylcobalamin forms, involved in methyl transfer and nucleic acid metabolism.

  • What is the biological function of Vitamin C (ascorbic acid)?

    Acts as an antioxidant, supports collagen formation, energy production, and reduces iron and Vitamin E.

  • How can enzyme activity in blood tests indicate organ damage?

    Elevated levels of specific enzymes (e.g., AST, ALT, CK, LDH) in blood indicate damage to organs like liver, heart, or pancreas.

  • What class of proteins is used in lateral flow assays for COVID-19 detection?

    Antibodies conjugated on the test strip bind to the SARS-CoV-2 spike protein to detect infection.