Enzymes: Structure and Function

Question 1

What are enzymes known as and why?

Answer 1

Biological Catalysts.
-Biological: They are found in all living organisms and cells.
-Catalysts: They speed up the rate of chemical reactions, without being used up or undergoing permanent changes.

Question 2

Describe the protein structure of enzymes.

Answer 2

-Majority are Globular proteins, with complex tertiary structures which determine their shapes of active sites.
-Some are found as single polypeptide chains.

Question 3

What do enzymes control in cells?

Answer 3

Metabolic pathways.

Question 4

Describe the 2 sites of action of enzymes.

Answer 4

-Intracellular: enzymes are produced and function inside the cell.
-Extracellular: enzymes are produced inside the cell via protein synthesis and then secreted out into the body via exocytosis.

Question 5

Describe the function of Catalase enzyme, and where they are found.

Answer 5

-Catalase converts Hydrogen Peroxide into water and oxygen, preventing damage to cells.
-Catalase is found in the peroxisomes of cells, and hydrogen peroxide is a byproduct of many metabolic reactions.

Question 6

Describe ONLY the function of Amylase.

Answer 6

-Amylase is involved in carbohydrate digestion, it hydrolyses starch into simpler, maltose disaccharides.

Question 7

Where is Amylase secreted from, and where are its sites of action?

Answer 7

-Amylase is secreted from the Salivary Glands and the Pancreas.
-Functions in the Mouth and Small Intestine respectively.

Question 8

Why is digestion usually carried by extracellular enzymes?

Answer 8

Because macromolecules which are ingested, are too large to enter the cell via endocytosis, or transport processes.