Diet (and digestion) B7

Question 1

carbohydrates

Answer 1

short term supply of energy

Question 2

proteins

Answer 2

growth and repair

Question 3

fats

Answer 3

long term energy supply and insulation

Question 4

vitamin C

Answer 4

growth and repair

Question 5

vitamin D

Answer 5

absorption of calcium (without vitamin D, calcium will be excreted as urine)

Question 6

calcium

Answer 6

strengthens bones, helps with muscle contraction and nerve transmission

Question 7

iron

Answer 7

prpoduction of red blood cells

Question 8

fibre

Answer 8

helps food and feces to move along the gut

Question 9

water

Answer 9

60% of body is made of water, it’s needed in almost every process

Question 10

constipation definition

Answer 10

occurs when there is a definciency of dietary fibre in the diet, makes it difficult to excrete feces

Question 11

starvation definition

Answer 11

occurs when a person doesn’t take in enough nutrients to meet their body’s energy requirements. At first, the body uses fat stores to fuel itself but once these stores are used up, it will begin to metabolise the protein in muscles

Question 12

scurvy definition (3 points)

Answer 12

a disease caused by lack of vitamin C
- feel very tired and weak all the time
- have severe joint or leg pain
- have swollen, bleeding gums

Question 13

rickets definition (1 point)

Answer 13

disease caused by lack of vitamin D
- soft and deformed bones due to being unable to absorb calcium

Question 14

Causes of low iron (6 points)

Answer 14

• blood loss (menstruation)
• pregnancy
• stomach ulcers (hole in stomach lining)
• certain medicines, like aspirin
• diseases (such as coeliac disease in which the intestines do not absorb enough iron)
• a lack of iron in diet

Question 15

absorption definition

Answer 15

when food particles move from the intestines and into the blood

Question 16

assimilation definition

Answer 16

when food moves from the blood and into the cells of the body where they are used

Question 17

mechanical digestion definition

Answer 17

mainly takes place in mouth as food is chewed

Question 18

chemical digestion definition

Answer 18

the chemical breakdown of large, insoluable molecules into smaller, soluabnle molecules

Question 19

The mouth in digestion (2 points)

Answer 19

• teeth for chewing
• amylase secreted by salivary glands breaks down starch into simple sugars

Question 20

the oesophagus in digestion (3 points)

Answer 20

• When we swallow, muscles along the oesophagus contract in waves, forcing the food down
• this process is called peristalsis
• chewed up ball of food - bolus

Question 21

the stomach in digestion (2 points + 2 subpoints)

Answer 21

• glands in the lining of the stomach release gastric juices
• gastric juice has 2 key components that help it break down food:
  
  • hydrochloric acid –> keeps pH around 1.5-3.5
  • enzymes (e.g. pepsin, a protease)

Question 22

the liver in digestion (1 point + 2 subpoints)

Answer 22

• Produces bile, which:
  
  • neutralises the acidic gastric juice as it enters the small intestine
  • emulsifies fat into small drops that can be more rapidly digested by lipase

Question 23

the gallbladder in digestion (1 point)

Answer 23

• Bile which is produced by liver is stored here

Question 24

the pancreas in digestion (2 points + 1 subpoint)

Answer 24

• secrets pancreatic juice into the small intestine (duodenum), which contains:
  
  • enzymes; amylase, lipase and trypsin
• also produces insulin (hormone that regulates blood sugar)

Question 25

the small intestine (duodenum) in digestion (1 point + 3 subpoints)

Answer 25

- Pancreatic juice starts to act on food here. It contains: - more amylase --> completes the chemical digestion of starch into simple sugars - trypsin --> breaks down protein into amino acids - lipase ---> breaks down fats into fatty acide and glycerol

Question 26

the large intestine in digestion (1 point + 3 subpoints)

Answer 26

- Three main parts: - colon: water and bile salts are absorbed - rectum: stores undigested food --> stool is formed - anus: egestation