Introduction to Enzymes and Biochemical Reactions

This flashcard set covers the fundamental concepts of enzymes, including metabolic reaction types, enzyme-substrate mechanisms, and the effects of temperature and pH on activity.

Enzymes

Protein molecules which act as biological catalyst, speeding up biochemical reactions without being used up.

Anabolic reaction

Reactions that involve the synthesis of macro molecules from micro molecules, such as joining up glucose molecules to make starch.

Catabolic reaction

Biochemical reactions which involve the breakdown of macromolecules into micromolecules, such as the digestion of starch into glucose.

Intra-cellular enzymes

Enzymes that catalyze reactions in the cytoplasm of the cells that formed them.

Extra-cellular enzymes

Enzymes that catalyze chemical reactions outside the cells that have formed them, such as digestive enzymes.

Substrates

Substances which are acted upon by enzymes; they possess specific shapes.

Active site

The specific region of an enzyme where the substrate binds to catalyze a reaction.

Enzyme-substrate complex

The structure formed when a substrate molecule fits perfectly to a specific enzyme.

Lock and Key model

A hypothesis explaining enzyme action where only the correct enzyme-substrate combination with corresponding shapes can work.

Optimum temperature

The specific temperature at which enzymes work best and the rate of reaction is at its highest.

Denature

A change in the protein structure and active site conformation of an enzyme at temperatures above $50$ degrees, resulting in a loss of function.

Reaction specificity

A property of enzymes meaning they specifically catalyze reactions involving certain substrates, such as amylase converting starch into maltose.

Optimum pH

The specific pH at which an enzyme catalyzes a reaction most effectively, such as pH $7 \text{--} 8$ for amylase.

Amylase

An enzyme that breaks down starch into maltose and glucose, functioning best at pH $7 \text{--} 8$.

Pepsin

A digestive enzyme that breaks down protein into peptides, functioning best under acidic conditions at pH $2$.

Iodine solution

A reagent that is reddish brown in color and turns blue-black in the presence of starch.

Copper sulphate and sodium hydroxide

Solutions used to test for the presence of proteins, yielding a purple color for a positive result and a light blue color for a negative result.

Kinetic energy

Energy that substrate and enzyme molecules contain, which is low at low temperatures resulting in a low frequency of collision.