B6 - Human Nutrition T9

Question 1

Why do we need digestive enzymes?

Answer 1

larger food molecules need to be digested into smaller soluble molecules so it can diffuse into cell membranes so body can use

Question 2

What does protease do

Answer 2

breaks down proteins into amino acids

Question 3

Source of protease

Answer 3

stomach + pancreas

Question 4

Where protease acts

Answer 4

stomach + small intestine

Question 5

Source of amylase

Answer 5

salivary glands + pancreas

Question 6

Where amylase acts

Answer 6

mouth + small intestine

Question 7

What does amylase do

Answer 7

breaks down starch into maltose

Question 8

What does maltase do

Answer 8

breaks down maltose into glucose

Question 9

Source of maltase

Answer 9

small intestine wall

Question 10

Where does maltase act

Answer 10

small intestine

Question 11

Source of lipase

Answer 11

pancreas

Question 12

Where does lipase act

Answer 12

small intestine

Question 13

What does lipase do

Answer 13

breaks fat molecule down into 3 fatty acids + 1 glycerol

Question 14

What enzyme group do pepsin and trypsin belong to?

Answer 14

protease

Question 15

Source of carbohydrates
Function of carbohydrates

Answer 15

Bread, cereals, pasta, rice,
potatoes
high energy source

Question 16

Source of proteins
Function of proteins

Answer 16

Meat, fish, eggs, pulses
cell growth and repair

Question 17

Source of lipids
Function of lipids

Answer 17

dairy, oil, nuts
high energy source and for insulation

Question 18

Source of fibre
Function of fibre

Answer 18

fruit, vegetables, bran
provide bulk to help intestine walls to move food and faeces along gut

Question 19

Source of Vitamin A
Function of Vitamin A

Answer 19

carrots, green vegeatbles, oily fish
needed for vision, strong immunity, growth

Question 20

Source of Vitamin C
Fucntion of Vitamin C

Answer 20

citrus fruits, broccoli
helps absorb iron, maitains healthy tissue, heals wounds

Question 21

Source of Vitamin D
Fucntion of Vitamin D

Answer 21

oily fish, margarine
helps absorb calcium = healthy bones + teeth

Question 22

Mineral

Source of Calcium
Fucntion of Calcium

Answer 22

dairy, leafy greens
bone and teeth strength (deficieny can cause ricktes),
normal blood clotting

Question 23

Mineral

Source of Iron
Fucntion of Iron

Answer 23

red meat, beans and nuts
produces haemoglobin in red blodd cells (deficiency causes anaemia)

Question 24

Source of Water
Fucntion of Water

Answer 24

water, juice, milk
so cell reactions take place

Question 25

Deficiency symptoms of low water/fibre

Answer 25

constipation
irregular bowel movements

Question 26

3 factors affecting energy requirements

Answer 26

1. age
2. activity
3. pregnancy

Question 27

How age affects energy requirements

Answer 27

amount of energy needed decreases as you go into adulthood
children need more energy as they are growing, compared to adults

Question 28

How activity affects energy requirements

Answer 28

If you are more active then you will need more energy for movement and muscle contractions

Question 29

How pregnancy affects energy requirements

Answer 29

energy requirements will increase in order to support growth of the foetus
energy needs also increase due to the extra mass of the baby

Question 30

Risks of having more energy in your diet than you use

Answer 30

body stores excess energy as body fat
can lead to :
obesity
increase risk of heart disease, type 2 diabetes, stroke and some cancer

Question 31

Order of digestive system

(human alimentary canal)

Answer 31

mouth
oesophagus
pancreas
stomach
small intestine(duodenum->ileum)
large intestine
rectum
anus

Question 32

What happens in the mouth

Answer 32

1. teeth break up large food pieces into
   smaller pieces with larger surface area to volume ratio (food
   bolus
2. salivary amylase breaks down starch into glucose
3. saliva lubricates food bolus - swallowed easily

Question 33

What happens in the oesophagus?

Answer 33

• tube from the mouth to the stomach
• food bolus moves down due to unidirectional wave-like contractions** (peristalsis)** created by circular muscles and longitudinal muscles that create a squeezing action

Question 34

What happens in the pancreas?

Answer 34

• Produces carbohydrase, protease and lipase enzymes
• secretes enzymes into the stomach and small intestine

Question 35

What happens in the stomach?

Answer 35

Gastric juice is released from stomach lining when it detects food in the stomach
● Gastric juice is made of
○ Pepsin: enzyme breaking down proteins
○ Hydrochloric acid: makes stomach acidic in order for pepsin to work and to kill any
ingested bacteria
● Peristalsis also occurs here

Question 36

What happens in the small intestine - duodenum?

Answer 36

The first part of the small intestine
● Carbohydrases, proteases and lipases digest food here
● Bile is released into the duodenum
● Peristalsis also occurs here

Question 37

What happens in the small intestine - ileum?

Answer 37

Lined with villi (finger-like projections) to maximise absorption of digested soluble molecules into blood

Question 38

How is the small intestine adapted for efficient absorption of the products of digestion?

Answer 38

1.long villi and micro villi - creates larger SA:V, quicker rate of diffusion
2.blood capiallaries and lacteal - maintain concentration gradient, speeds up rate of diffusion
3.thin wall (1 cell thick) - shorter diffusion distance, speeds up rate of diffusion

Question 39

What happens in the large intestine?

Answer 39

Water is absorbed here, to produce faeces
● Faeces is stored in the rectum and the removed through the anus

Question 40

Where is bile produced and stored?

Answer 40

produced in liver
stored in gallbladder

Question 41

(2 points)

What are the roles of bile?

Answer 41

1. neutralises HCl (stomach acid) so pancreas enzymes can work at optimum pH
2. emulsifies large fat globules so larger SA:V -> lipase can break down fat molecules into fatty acids and glycerol quicker