B5- Animal tissues, organs and systems

Question 1

What is the main function of the digestive system?

Answer 1

To digest food and absorb the nutrients obtained from digestion.

Question 2

What is the role of the pancreas and the salivary glands in the digestive system?

Answer 2

The pancreas and salivary glands are glands which produce digestive juices containing enzymes.

Question 3

What is the role of the stomach in the digestive system?

Answer 3

Produces HCL- which kills bacteria present and provides optimum pH for the enzyme protease to function.

Question 4

What is the role of the small intestine in the digestive system?

Answer 4

The small intestine is the site where soluble food molecules are absorbed into the bloodstream.

Question 5

What is the role of the liver in the digestive system?

Answer 5

Produces bile (which is stored in the gallbladder) which emulsifies lipids and allows the lipase enzyme to work efficiently.

Question 6

What is the role of the large intestine in the digestive system?

Answer 6

Absorbs water from undigested food, producing faeces.

Question 7

What is the role of enzymes in the digestive system?

Answer 7

Enzymes act as a biological catalyst which speeds up the rate of biological reactions (the breakdown of food) without being used up.

Question 8

How does the shape of an enzyme affect its function?

Answer 8

Enzymes have a specific active site which is complementary to the substrate.

Question 9

Definition- Metabolism

Answer 9

The sum of all the reactions in a cell or organism.

Question 10

What types of metabolic reactions do enzymes catalyse? (3)

Answer 10

• Building large molecules from smaller ones (e.g. glucose into starch)
• Changing one molecule to another (e.g. glucose into fructose)
• Breaking down large molecules into smaller ones.(e.g. carbohydrates into glucose)

Question 11

Explain the lock and key analogy for enzymes

Answer 11

The shape of the enzyme active site is complementary to the substrate, so can bind together to form an enzyme-substrate complex.

Question 12

How does temperature affect enzyme action?

Answer 12

Increasing temp. increases enzyme action as molecules collide more producing more energy.

Question 13

What happens if you go above a certain temperature ?

Answer 13

Shape of the active site is altered and enzyme denatures and is no longer complementary to the substrate (no reaction)

Question 14

How does pH effect enzyme action?

Answer 14

For most optimum is 7 (except for protease in the stomach). If pH varies too much active site denatures.

Question 15

Where are lipases produced? (2)

Answer 15

-Small intestine
-Pancreas

Question 16

Where are proteases produced? (3)

Answer 16

-Small intestine
-Pancreas
-Stomach

Question 17

Where are amylases produced?

Answer 17

-Pancreas
-Mouth

Question 18

Role of amylase

Answer 18

Breaks down starch into sugars

Question 19

Role of protease

Answer 19

Breaks down protein into amino acids

Question 20

Role of lipase

Answer 20

Breaks down lipids into fatty acids and glycerol

Question 21

Where is bile made?

Answer 21

Liver

Question 22

Where is bile stored?

Answer 22

gall bladder

Question 23

Role of bile (2)

Answer 23

• Neutralises HCL in the stomach
• Emulsifies fats into droplets (increasing surface area for enzyme to work)

Question 24

Purpose of the circulatory system

Answer 24

Carry useful products to tissues and remove waste products