U1.2 Enzymes and the Digestive System

Question 1

What are the three main monosaccharides?

Answer 1

glucose, fructose, galactose

Question 2

What do glands produce?

Answer 2

enzymes

Question 3

What do enzymes in the digestive system do?

Answer 3

Break down large, insoluble molecules into smaller, soluble ones ready for digestion

Question 4

Where are the salivary glands and what do they do?

Answer 4

Near the mouth and it secretes salivary amylase via duct into the mouth to break down food

Question 5

What does salivary amylase break down?

Answer 5

Starch into maltose

Question 6

What pH does salivary amylase work best at?

Answer 6

a neutral pH of 7

Question 7

How is neutral environment maintained in the mouth?

Answer 7

Mineral salts in the saliva maintain the neutral pH of 7

Question 8

What does the oesophagus do in the digestive system?

Answer 8

moves food from the mouth to the stomach via peristalsis

Question 9

Describe the phyiscal features of the oesphagus and how it is suited its function

Answer 9

Thick muscular wall, lined with flattened epithelial cells and mucus that wears away and is replaced to protect the lining of the oesphagus.

Question 10

What does the stomach do in the digestive system?

Answer 10

It stores and digests food, especially proteins.
Produces proteases which digests proteins.
HCl which kills microorganisms.

Question 11

How does the stomach protect itself from self digestion?

Answer 11

the goblet cells in the stomach secrete mucus to protect the stomach from being digested by the HCl and its own enzymes

Question 12

How does the stomach make digestion of food more efficient?

Answer 12

it churns up food and increase the surface area of the substrate.

Question 13

Which enzyme breaks down protein?

Answer 13

Pepsin

Question 14

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

Answer 14

It digests food using enzymes and the products are absorbed into the bloodstream

Question 15

What is the process of taking food in called?

Answer 15

Ingestion

Question 16

What is the process of taking food molecules into the blood called?

Answer 16

Absorption

Question 17

Molecules released from digestion can be incorporated into body tissue or used within the body, what is this process called?

Answer 17

Assimulation

Question 18

What is the process of molecules leaving the body as faeces called?

Answer 18

Egestion

Question 19

Describe how the small intestine is suited to its function

Answer 19

It’s a long muscular tube and its inner walls are folded into villi, giving it a larger surface area.

Question 20

How is the surface area of the small intestine increased?

Answer 20

The inner walls are folded into villi which give it a larger surface area and this is further increased further by microvilli on the epithelium of each villus

Question 21

What does the large intestine do?

Answer 21

Absorbs water, most re absorbed water comes from secretions of digestive glands. The food becomes direr and forms faeces

Question 22

What is the pancreas and where is it situated?

Answer 22

A large gland below the stomach.

Question 23

What does the pancreas do?

Answer 23

Secretes pancreatic juice which contains

• protease
• amylase
• lipase

Question 24

What does protease do?

What product does it make?

Answer 24

hydrolyses proteins into amino acids

Question 25

What does amylase do?

What product does it make?

Answer 25

hydrolyses starch into maltose

Question 26

What does lipase do?

What products are made?

Answer 26

hydrolyses lipids into fatty acid and glycerol

Question 27

What are the two different types of digestion?

Answer 27

Mechanical and chemical

Question 28

What does mechanical digestion consist of?

Answer 28

Ingestion, mastication, peristalsis to increase surface area

Question 29

What does chemical digestion do?

Answer 29

Uses enzymes to break down large insoluble molecules into smaller soluble molecules

Question 30

Where is the duodenum in the digestive system?

Answer 30

The 1st part of the small intestine

Question 31

What does carbohydrase do?

What product is made?

Answer 31

hydrolyses carbohydrates into monosaccharides

Question 32

What does maltase do?

What product is made?

Answer 32

hydrolyses maltose into a-glucose

Question 33

Why does it take several enzymes to break down a large molecule into its monomers?

Answer 33

Because enzymes are specific

Question 34

Where is the enzyme amylase made?

Answer 34

In the mouth and pancreas

Question 35

What is hydrolysis?

Answer 35

the splitting up of molecules by adding water to break their chemical bonds.

Question 36

What is the monomer unit of a carbohydrate called?

Answer 36

Monosaccharide

Question 37

What is the polymer of carbohydrates called?

Answer 37

polysacccharides

Question 38

What test is used to test for reducing sugars?

Answer 38

Benedicts Test