Lecture 12 – Enzymes I

A collection of vocabulary flashcards based on the concepts discussed in Lecture 12 about enzymes, coenzymes, Pellagra, and reaction kinetics.

Coenzymes

Compounds that associate with enzymes, typically near or around the active site, allowing for metabolic processes to occur.

Pellagra

A disease caused by niacin deficiency, characterized by the three 'Ds': diarrhea, dermatitis, and dementia.

Enzymes

Biological catalysts that speed up chemical reactions without being consumed in the process.

Active site

The region of an enzyme where substrate binds and the reaction occurs.

First-order reaction

A reaction in which the rate is directly proportional to the concentration of one reactant.

Transition state

The high-energy state during the transformation of substrates into products.

Induced Fit Hypothesis

The model proposing that an enzyme changes its shape to fit the substrate better upon binding.

Oxidoreductases

A category of enzymes that catalyze oxidation/reduction reactions.

Transferases

Enzymes that transfer a functional group from one molecule to another.

Hydrolases

Enzymes that cleave molecules by the addition of water.

Ligases

Enzymes that catalyze the joining of two molecules.

Rate-limiting step

The slowest step in a reaction pathway that determines the overall reaction rate.

Metal cofactors

Metal ions required for the proper functioning of many enzymes, aiding in catalysis.

NAD+

Nicotinamide adenine dinucleotide, a coenzyme involved in redox reactions.

Viability of reaction rates

How effective enzymes are at increasing the rate of a chemical reaction compared to non-enzymatic processes.

Vitamin B3

Also known as niacin, crucial for the production of NAD+ and NADP, serving as important cofactors in enzyme reactions.

Lock and Key model

A model of enzyme activity suggesting that the enzyme and substrate have specific complementary shapes.

Hydration shells

Layers of water molecules that surround ions or molecules, influencing reaction rates.

Thermodynamics in enzyme activity

The study of energy transformations and how they relate to the catalyzing effect of enzymes.

Vitamins

Organic molecules needed in small amounts for health, growth, and reproduction, often acting as coenzymes.

Epithelial cells

Cells that line the surfaces and cavities of structures throughout the body, which require niacin for their high turnover rate.