Enzymes and Coenzymes

Flashcards covering the properties, mechanisms, and specific examples of enzymes, cofactors, and coenzymes from Chapter 9.

Enzymes

Biological catalysts that speed up chemical reactions, allowing them to occur more quickly and efficiently.

Activation energy

The amount of energy required to get a chemical reaction going, which enzymes decrease to make reactions more efficient.

Substrate

The specific substance that an enzyme binds to or acts upon.

Substrate specific

The characteristic of enzymes where every enzyme has one particular thing it can bind to, meaning specific enzymes are required for specific reactions.

Metabolic pathways

Processes governed by many enzymes that regulate various chemical reactions within the body.

Cofactor

A helper substance, such as inorganic minerals like manganese or magnesium, that combines with an inactive enzyme to convert it into an active enzyme.

Coenzyme

An organic cofactor that contains carbon, typically derived from vitamins, which helps enzymes perform their functions.

B vitamins

A group of organic cofactors that often act by donating or accepting electrons to assist enzymes in metabolic reactions.

$$NAD$$

An acronym for nicotinamide adenine dinucleotide, which is the coenzyme form of niacin (vitamin $B_{3}$) that acts as an electron donor or acceptor.

Niacin

Also known as vitamin $B_{3}$, this vitamin forms the coenzyme $NAD$.

Pyruvate

A molecule that can be converted into lactate (lactic acid) by an enzyme when no oxygen is present in the cell.

Lactate

Also known as lactic acid, this compound is formed from pyruvate in a reaction driven by an enzyme and the coenzyme $NAD$..

Lactate dehydrogenase

The specific enzyme that catalyzes the chemical reaction to convert pyruvate into lactate.

Reduced form

The state of a coenzyme, such as $NADH$, when it has added electrons and hydrogen to donate to a reaction.

$$FAD$$

A coenzyme derived from riboflavin (vitamin $B_{2}$) that accepts and donates electrons to help enzymes catalyze metabolic reactions.

Riboflavin

Also known as vitamin $B_{2}$, this vitamin forms the coenzyme $FAD$.