Digestion

Question 1

Mechanical

Answer 1

• breaks down food by chewing with teeth

Question 2

Chemical

Answer 2

• uses proteins called enzymes

Question 3

Enzymes

Answer 3

• biological catalysts which speed up the rate of chemical reactions in the body

Question 4

Mouth

Answer 4

• digestion starts here
• saliva contains enzymes (amylase) that breaks down carbohydrates
• chemical and mechanical digestion

Question 5

Oesophagus

Answer 5

• food pipe

* links the mouth to the stomach

Question 6

Stomach

Answer 6

• the food mixes with protease enzymes which digest proteins
• contains muscular tissue to move the stomach wall and churn up food
• hydrochloric acid is present and kills harmful bacteria
• hydrochloric acid gives a low pH for enzymes to work

Question 7

Liver

Answer 7

• makes bile which breaks down fats into tiny droplets (emulsification)
• alkaline to give the right pH for the enzymes in the small intestine

Question 8

Pancreas

Answer 8

• contains glandular tissue
• makes 3 enzymes: protease which breaks down protein, lipase which breaks down lipids and amylase which breaks down carbohydrates

Question 9

Small intestine

Answer 9

• produces more enzymes to further digest proteins, carbohydrates and fats
• food is absorbed through the gut wall into the blood which then takes it around the body to wherever it is needed
• covered in villi

Question 10

Large intestine

Answer 10

• water is absorbed

Question 11

Rectum

Answer 11

• undigested food is stored as faeces

Question 12

Villi

Answer 12

• absorb food and found in the small intestine
• thin outer layer of cells
• good blood supply
• large surface area for absorption

Question 13

Bacteria in the gut

Answer 13

• unicellular organisms
• produce enzymes
• make useful vitamins
• produce useful hormones
• reduce the possibility of bacteria growing in your intestines and making you ill