W - BIOL200 - 2.2-2.4 ENZYMES, ENZYME REGULATION, AND PROTEIN PURIFICATION

What do enzymes do?

Catalyze (speed up) reactions.

What is an example of an enzyme breaking down lactose?

Lactase.

What is an example of an enzyme involved in protein digestion?

Pepsin

What kind of protein is amylase?

An enzyme that breaks down starch.

What part of the enzyme binds to the substrate?

The active site.

What do enzymes reduce to speed up reactions?

Activation energy.

Are enzymes used up during reactions?

No, they are not consumed.

What is enzyme regulation?

Control of enzyme activity by molecules.

What is feedback inhibition?

End product inhibits an earlier step.

What is competitive inhibition?

Inhibitor binds the active site.

What is non-competitive inhibition?

Inhibitor binds elsewhere, changing enzyme shape.

What’s allosteric regulation?

Regulator binds at a site other than the active site.

What’s an activator in enzyme regulation?

Molecule that increases enzyme activity.

What does protein purification mean?

Isolating one protein from a mixture.

What are protein purification techniques based on?

Size, charge, and affinity.

What is column chromatography?

Separation based on properties using a column.

What is affinity chromatography?

Uses specific binding to purify a protein.

What happens in gel filtration chromatography?

Small proteins enter beads, large proteins elute first.

What’s ion exchange chromatography?

Separates proteins by charge.

What is the stationary phase in chromatography?

The material inside the column (like beads).

What’s the mobile phase in chromatography?

The solution that moves through the column.