Chemistry - Enzymes

What are enzymes

Biological catalysts that follow rules of catalyst. Accelerate reaction by decreasing activation energy

3 main characteristics of enzymes

Can be reused/regenerated

DOESNT change equilibrium, only the reaction rate

Large proteins that may need assistance

Substrate =

Reactant

Active site =

enzyme’s specific pocket where substrate binds

Specificality

usually specific to substrate

What is ES Cycle

Enzyme + Substrate = ES Complex → Enzyme Product (EP) → E + P

Enzyme Structure

Proteins w/ 3D shape

Cofactors are

Metal/organic compounds that help in a reaction

What does a coenzyme refer to

Organic Compound ONLY (ex: water soluble)

How do you get cofactors

Diet source + water soluble vitamin intake

Cofactor has a

nonprotein component

Apoenzyme is the…

protein portion of enzyme

Holoenzyme

protein + cofactor

Oxidoreductases enzymes do

Oxidation/reduction

Transferase enzymes ____ one funct. group from 1 molecule to another

move; ATP as reactant

Hydrolases

Hydrolysis; add or remove H2O

Lyase

Form OR break C-C bond w/o ATP

Ligase

Form OR break C-C bond WITH ATP

Isomerase

Atom rearrangement

What are the enzyme specificity models

Lock + Key AND Induced Fit

What is the function of an enzyme (hint: 2 functions)

bring reactant together + hold reactant in correct orientation and distance

Michaelis-Mention Equation

$$V=\frac{V\max\left\lbrack S\right\rbrack}{Km+\left\lbrack S\right\rbrack}$$

Equation Parts

Vmax = Max reaction rate

Km= M-M constant (describes specificity)

[S] = Substrate concentration

What are the two kinds of enzyme inhibition

Irreversible and reversible

Irreversible inhibition

Broken down enzyme due covalent bind (ex: lead)

Reversible inhibition

No enzyme damage (ex: ibuprofen); two subtypes!

Competitive reversible enzyme inhibition

Bind at enzyme’s active site

Non-competitive reversible enzyme inhibition

bind enzyme to NON-active site to change active site’s shape → less accessible substrate