Enzymes-Basics

Question 1

What are enzymes?

Answer 1

Proteins that speed up metabolic reactions without being changed or used up themselves.

Question 2

What do enzymes catalyse?

Answer 2

-Reactions that change molecules
-Catabolic reactions
-Anabolic reactions

Question 3

What are Catabolic reactions?

Answer 3

Break molecules down

Question 4

What are Anabolic reactions?

Answer 4

Join small molecules together
-including those that produce structural components e.g. Collagen

Question 5

What are the 2 types of Enzyme action?

Answer 5

-Intracellular
-Extracellular

Question 6

What is Intracellular enzyme action?

Answer 6

Inside cells

Question 7

What is an example of Intracellular enzyme action?

Answer 7

Catalase breaks hydrogen peroxide inside hepatocytes.

Question 8

What is Extracellular enzyme action?

Answer 8

Outside cells

Question 9

What is an example of Extracellular enzyme action?

Answer 9

Amylase breaks starch down into maltose & trypsin & pepsin break larger polypeptides i9nto smaller polypeptides in the digestive system.

Question 10

What type of proteins are enzymes?

Answer 10

Globular

Question 11

What type of protein structure do enzymes have and what does it do for the cell?

Answer 11

Tertiary Structure that determine the shape of the active site.

Question 12

What is the ‘original’ theory for enzyme action?

Answer 12

Lock and Key

Question 13

What theory was the Lock and Key replaced with?

Answer 13

Induced Fit Model

Question 14

What is the Induced Fit Model?

Answer 14

The shape of the active site changed slightly to fit more closely around the substrate.

Question 15

How do enzymes work?

Answer 15

By reducing the activation energy. They do this in 2 ways.

Question 16

What is the first way an enzyme reduces the activation energy?

Answer 16

When 2 substrates need to be joined, the are held together closely in the active site so bonds can easily form.

Question 17

What is the second way an enzyme reduces the activation energy?

Answer 17

When a substrate needs to be broken, it fits into the active site in a way that strains the bonds so they can be broken more easily.

Question 18

Where is starch digested?

Answer 18

Starts in mouth and continues in small intestine.

Question 19

How many steps is starch digested in?

Answer 19

2

Question 20

What is the first step in starch digestion?

Answer 20

-Starch polymers a partially broken down into maltose (a disaccharide).
-Amylase is involved in this stage which is produced by the salivary glands and the pancreas.
-Released in saliva in mouth and pancreatic juice in small intestine.

Question 21

What is the second step in starch digestion?

Answer 21

-Maltose is then broken down into glucose (a monosaccharide).
-Maltose is involved in this stage which is present in the small intestine.

Question 22

Glucose is small. Where can it therefore be absorbed?

Answer 22

By the cells lining in the digestive system and therefore into the bloodstream

Question 23

How are proteins digested?

Answer 23

Trypepsin is a protease which catalyses the digestion of proteins into smaller peptides, then further broken down into amino acids by other proteases.

Question 24

Where is Trypepsin produced and released?

Answer 24

Produced in pancreas and released with pancreatic juice in small intestine.

Question 25

Where are amino acids produced by action of proteases absorbed?

Answer 25

By cells lining in digestive system and into bloodstream