Diet and digestion

Question 1

3 nutrients

Answer 1

Carbohydrates, Proteins, Fats

Question 2

What is the function of Carbohydrates?

Answer 2

Main fuel for respiration

Question 3

What is the function of Proteins?

Answer 3

Growth and repair of cells and tissue

Fuel for respiration

Question 4

What is the function of Fats

Answer 4

Store of energy
(Thermal and electrical) respiration
Fuel for respiration

Question 5

What is the Energy unit?

Answer 5

Kilojoules (kJ)

Question 6

How do you measure amount of energy in food?

Answer 6

Burn a known mass of food
Use thermal energy released to heat known volume of water
Measure finishing temperature of water
Calculate temp change

Question 7

State all the vitamin types

Answer 7

A, C, D

Question 8

State some minerals

Answer 8

Iron, Calcium

Question 9

What is the use of iron?

Answer 9

Forms part of haemoglobin which binds with oxygen

Question 10

What is the use of calcium?

Answer 10

Needed to form bones and teeth

Question 11

What is the effect of iron deficiency?

Answer 11

Anaemia

Question 12

What is the effect of calcium deficiency?

Answer 12

Rickets

Question 13

What is the use of vitamin A?

Answer 13

Making a chemical in the retina and also protects surface of eye

Question 14

What is the use of vitamin C?

Answer 14

Needed for cells and tissue to stick together

Question 15

What is the use of vitamin D?

Answer 15

Needed to absorb Calcium and phosphate ions form food

Question 16

Effect of vitamin A deficiency

Answer 16

Night blindness and damaged cornea

Question 17

Effect of vitamin C deficiency

Answer 17

Scurvy

Question 18

Effect of vitamin D deficiency

Answer 18

Rickets, weakness in bones

Question 19

Use of water

Answer 19

Used to transport components of blood and is crucial for temperature regulation e.g. sweating

Question 20

Use of fibre

Answer 20

Plant material (cannot digest)
Mainly a chemical called cellulose
Helps movement of food through intestine
Prevents constipation and bowel cancer

Question 21

List the parts of alimentary canal from mouth to anus

Answer 21

Mouth
Oesophagus
Stomach
Duodenum/
Ileum/
Colon*
Anus*
/ = small intestine
* = large intestine

Question 22

Stages of food processing

Answer 22

Ingestion
Digestion
Absorption
Assimilation
Egestion

Question 23

What is Ingestion?

Answer 23

Taking food through the mouth and swallowing

Question 24

What is Digestion?

Answer 24

Breaking down large insoluble molecules in food into smaller pieces and smaller, soluble molecules

Question 25

What is Absorption?

Answer 25

Movement of small soluble molecules out of gut and into blood by diffusion and active transport

Question 26

What is Egestion?

Answer 26

Passing out of undigested food through anus

Question 27

What is Assimilation?

Answer 27

Building larger biological molecules from small soluble molecules in all cells

Question 28

What is Mechanical digestion?

Answer 28

Food is broken down into smaller pieces in mouth by chewing | Increases surface area for enzymes and also prevents discomfort when swallowing

Question 29

What is Chemical digestion?

Answer 29

Salvia is released into mouth by salivary glands Makes food easier to swallow and contains amylase (enzyme) Amylase breaks down starch to maltose Amylase works best at neutral pH so is denatured in stomach

Question 30

What happens when you swallow food?

Answer 30

Food shaped into ball by tongue Moved towards back of mouth ( a bolus) Flap called epiglottis stops food from entering trachea

Question 31

What is the Oesophagus and what does it do?

Answer 31

Long tube connects mouth to stomach Food is pushed down by peristalsis 2 sets of muscles push food down oesophagus Circular muscles contract behind bolus pushing food down When longitudinal muscles contract they make oesophagus wider

Question 32

Which enzyme in the stomach helps digest protein?

Answer 32

.................Pepsin Protein------------------>Peptide Stomach contracts mixing the enzymes and food together

Question 33

Pepsins optimal conditions

Answer 33

Acidic pH Gastric glands release hydrochloric acid into stomach Keeps low pH

Question 34

Digestion happens in...

Answer 34

...Duodenum (small intestine)

Question 35

How does digestion occur in duodenum?

Answer 35

Pancreas makes several enzymes Secretes them into duodenum ``` ..............Pepsin Protein---------->Peptide ............Amylase Starch----------->Maltose ........Lipase Fat------------>Glycerol + 3 fatty acids ```

Question 36

Duodenum wall secretes which enzymes?

Answer 36

Maltase, Peptidase ...............Maltase Maltose---------->Glucose .............Peptidase Peptide---------->Amino acids

Question 37

What else does duodenum contain?

Answer 37

Bile Produced by liver and stored in gall bladder Before released into duodenum through bile duct

Question 38

What is the function of bile in the duodenum?

Answer 38

1.Neutralises stomach acid Enzymes work best at pH 7-8 2.Emulsifies lipids Breaks large droplets into smaller droplets, increase surface area for lipase to digest the fats

Question 39

What does the ileum do?

Answer 39

Absorption process | Villi absorb small soluble molecules through diffusion or active transport

Question 40

How does the ileum increase the rate of diffusion?

Answer 40

Large surface area Villi and Microvilli increase surface area Short diffusion distance Villi walls 1 cell thick High concentration gradient Provided by capillary network and lacteals

Question 41

What is the colon?

Answer 41

Site for reabsorption of water

Question 42

What does the Rectum do?

Answer 42

Stores faeces

Question 43

Colon and Rectum are both part of...

Answer 43

...Large intestine