Digestion

Question 1

What happens in Ingestion

Answer 1

This is when food enters your mouth

Question 2

What occurs in digestion

Answer 2

Hydrolysis of large insoluble molecules into small soluble ones, using enzymes

Question 3

What happens in absorption

Answer 3

Molecules pass through the epithelium of the small intestine to enter the blood or lacteal

Question 4

What happens in Egestion

Answer 4

Faeces (undigested food, bacteria, enzymes, cells) is removed at the anus

Question 5

What is the salivary glands

Answer 5

Produces saliva (with amylase)

Question 6

What is the function of the large Intenstine

Answer 6

This is where water is absorbed

Question 7

What does the liver do

Answer 7

It is the large organ that produces bile

Question 8

What does the pancreas do

Answer 8

Produces lipase and amylase

Question 9

What is the role of the gall bladder

Answer 9

This is where bile is stored

Question 10

What does the stomach contain?

Answer 10

HCl and Protease

Question 11

Explain how Carbohydrate Digestion works

Answer 11

The products are monosaccharides and absorbed by a co transport mechanism with Na+ into epithelial cells

Question 12

Explain the process of Absorption

Answer 12

Takes place in ileum (small intestine). Lining is folded into villi and epithelial cells have microvilli to increase available surface area for absorption. Monosaccharides and Amino acids enter blood in capillary

Question 13

What are the roles of bile?

Where is it produced and stored?

Answer 13

Produced in liver
Stored in gall bladder
Flows down bile duct to duodenum
Neutralises acidic contents in stomach. It contains Bile salts which emulsify fats

Question 14

What is emulsification

Answer 14

Breaking large fat globules into smaller droplets, increasing available surface area for lipase to work on.

Question 15

What are micelles

Answer 15

They are made of fatty acids, monoglyerides and bile salts. They transport lipid soluble fatty acids and monoglyerides to the surface of the microvilli where absorption occurs. Monoglyerides and fatty acids diffuse through as they are lipid soluble

Question 16

What happens in the epithelial cell for lipid digestion

Answer 16

Triglycerides are resynthesised into S.E.R
They combine with cholesterol, protein + phopholipids to form chylomicrons in golgi body. They leave via exocytosis and enter blood system via lymph vessel (lacteal)

Question 17

What is a chylomicron

Answer 17

Water soluble droplets made of triglycerides, cholesterol, protein +, phospholipid

Question 18

What are endopeptidases

Answer 18

Protein digestin enzyme which break peptide bonds in the middle of polypeptide chain to form smaller polypeptides. Examples are pepsin + trypsin. It is efficient to do this so more end for exopeptidases to work on

Question 19

What are exopeptidases

Answer 19

Protein digestin enzyme which breaks the peptide bonds at the end of the chains releasing single amino acids or dipeptides

Question 20

Describe how proteins are digested

Answer 20

Hydrolysis of peptide bonds
Endopeptidases break polypeptides into smaller peptide chains
Exopeptidases releases single amino acids
Dipeptides break down into amino acids

Question 21

How is alpha glucose assimilated?

Answer 21

It is absorbed by co-transport with Na+

Question 22

Where is amylase secreted?

Answer 22

The salivary glands and the pancreas

Question 23

Where is maltase secreted?

Answer 23

In the small intestine

Question 24

How are large lipid droplets broken down?

Answer 24

Bile salts are added in the process of emulsification

Question 25

How are small lipid droplets broken down?

Answer 25

Two ester bonds between fatty acid molecules and glycerol are broken and a monoglyceride and two fatty acids are present as micelles

Question 26

How are amino acids absorbed?

Answer 26

By co-transport with Na+