Enzymes

Unit 7 Enzymes

Enzyme

Most enzymes are proteins that act as biological catalysts and are essential to the functioning of a cell.

Catalyst

Molecules that increase the rate of a chemical reaction without being changed or used up in the reaction.

Ribozyme

An example of an RNA enzyme that joins amino acids together in the ribosome.

Induced Fit Model

Enzyme reactions depend on the physical fit between the enzyme and the substrate.

Substrate

The reactant (molecule) that is being catalyzed by a certain enzyme.

Active Site

The location where the substrate attaches to the enzyme.

Activation Energy

The amount of energy needed for a chemical reaction to occur; it is lower with enzymes.

Optimal Temperature

The temperature at which an enzyme works best.

Optimal pH

The pH at which an enzyme works best.

Denature

The process by which drastic changes in temperature and pH can cause a change in an enzyme's shape.

Enzyme Concentration

If an increase in enzyme concentration causes the rate of the reaction to increase, then the enzyme is the limiting factor.

Substrate Concentration

If an increase in substrate concentration causes the rate of reaction to increase, then the substrate is the limiting factor.

-ASE

Most enzyme names end with these letters, indicating they are enzymes.

-OSE

Most names of simple sugars end with these letters.

Sucrase

An enzyme that breaks down sucrose.

Amylase

An enzyme that breaks down starch.

Shape and Function

The shape of an enzyme is determined by the sequence of amino acids in its structure, and it determines the enzyme's function.

DNA and Enzymes

DNA determines the sequence of the amino acid chains in enzymes.

Energy without Enzymes

Chemical reactions can still occur without enzymes but require much more energy.

Enzyme Activity

A measure of how well an enzyme catalyzes a reaction, influenced by factors like temperature and pH.