Digestive system

Question 1

order of events in digestion

Answer 1

Ingestion: food taken into mouth
Digestion: food broken down through chemical reactions, where it’s converted into smaller molecular forms
Absorption: (NUTRIENTS ABSORBED) small molecular forms are absorbed through the cells of your digestive system and pass into nearby blood or lymphatic vessels
Transport: your circulatory system delivers the small molecular nutrients to your body cells
Egestion: waste is stored and expelled.

Question 2

what are humans incapable of digesting

Answer 2

cellulose as they dont have the cellulase enzyme

Question 3

role of enzymes in digestion

Answer 3

Digestive enzymes are added as the food moves down the digestive system
Enzymes act as catalysts & Lower the activation energy
Reactions within the digestive system are all hydrolysis reactions

Question 4

why do humans have prime conditions for enzyme activity

Answer 4

Humans have a body temp. Of 37oC as this is a good temperature for good molecular movement + for the enzymes to work in their optimum environment

Question 5

amylase

Answer 5

found in mouth, pH 7, breaks down starch to sugar (to maltose and then further to glucose

Question 6

pepsin

Answer 6

found in stomach, pH 1-2, breaks down proteins

Question 7

lipase

Answer 7

found in pancreas + small intestine, ph 8, breaks down fats

Question 8

other enzymes

Answer 8

found in pancreas + small intestine, ph 8, completes breakdown of sugar and proteins

Question 9

mouth

Answer 9

using the teeth, mechanical digestion occurs here, as the food is ground up. The salivary glands also release enzymes (amylase, pH 7) to break down starch into sugar (maltose, which is then ultimately broken down into glucose) and moisten the food

Question 10

OESOPHAGUS

Answer 10

Food travels down the oesophagus tract through peristalsis

Question 11

STOMACH

Answer 11

Food is turned into chyme through acids and enzymes (churning)
Chemical and mechanical digestion
Pepsin breaks down proteins into amino acids (pH 2-3)

Question 12

LIVER

Answer 12

Toxins are filtered from the blood
Bile is produced (BILE: increases absorption of fats, by breaking them into small droplets that the enzyme lipase can attack)

Question 13

GALL BLADDER

Answer 13

Bile is stored here and eventually released into the small intestine

Question 14

SMALL INTESTINE

Answer 14

Absorption of nutrients and minerals, and continuation of food digestion

Question 15

Large Intestine

Answer 15

Recycles water and mineral salts back into bloodstream via diffusion
Excretes the undigested material
Enzyme maltase catalyses the hydrolysis of maltose into glucose

Question 16

Rectum

Answer 16

Storage of faeces

Question 17

Anus

Answer 17

Storage of faeces

Question 18

Pancreas

Answer 18

• produces insulin and glucagon hormones

lipase, amylase and endopeptidase enzyme production thats released into the small intestine (pancreatic juice)