chapter 14

Question 1

why do we eat

Answer 1

food provides nutrients to our body to carry out cellular activities

Question 2

what cellular activities

Answer 2

respiration to release energy to carry out processes

Question 3

types of nutrients

Answer 3

1) carbohydrates: rice, bread,
2) proteins:vegetable, fruits, meat
3) fats: tuna, cooking oil, yoghurt

Question 4

digestion starts at the:

Answer 4

mouth and ends at the anus

Question 4

why does food need to be broken down

Answer 4

absorption of nutrients by the body and used by the body cells

Question 5

physical digestions

Answer 5

the physical act of breaking down food into smaller pieces

Question 6

chemical digestion

Answer 6

breaking down food through the action of biological molecules (enzymes)

Question 7

role of enzymes

Answer 7

speeds up process of breaking down large food molecules into smaller molecules

Question 8

types of enzymes

Answer 8

carbohydrases proteases, lipases

Question 9

carbohydrases

Answer 9

carbohydrates -> simple sugars

Question 10

proteases

Answer 10

proteins -> amino acids

Question 11

lipases

Answer 11

fats -> fatty acids and glycerol

Question 12

mouth: (pd, cd, functions)

Answer 12

pd: chewing helps breaks down food into smaller pieces
cd: saliva contains carbohydrases, which will partially digest starch
functions: saliva softens and lubricates food for easy swallowing

Question 13

gullet; (pd,cd,functions)

Answer 13

pd: none, does not release digestive juices
cd: starch from the mouth continues to be digested by carbohydrases mixed with food
functions: muscle of gullet pushes food into stomach

Question 14

stomach (pd,cd,functions)

Answer 14

pd: churns food into smaller pieces
cd: release gastric ulcer that contains proteases to digest proteins

Question 15

functions of stomach

Answer 15

• gastric juice contains hydrochloride acid, killing harmful microorganisms to allow proteases to digest
• thick layer mucus to protect tissues from damage caused by hydrochloric acids and proteases in gastric juice
• muscle at both ends of the stomach controls food entering and leaving the stomach

Question 16

small intestine (pd,cd,functions)

Answer 16

pd: none
cd: main site for chemical digestion due to enzymes released ‘
- fats are first digested due to presence of lipases
- carbohydrates, proteins and fats are fully digested here

Question 17

large intestine

Answer 17

some of the remaining water and mineral salts in the food are absorbed into the bloodstream

Question 18

anus

Answer 18

faeces are released through the opening

Question 19

place for digestions, carbohydrate

Answer 19

1) mouth: partially
2) gullet: starch from mouth continues to be chemically digested as food moves down
4) small intestine: all carbohydrates are digested into simple sugars

Question 20

places for digestion, proteins

Answer 20

1) stomach: gastric juice contains proteases to partially digest proteins
2) all proteins are digested by proteases into amino acids

Question 21

places for digestion, fats

Answer 21

1) small intestine: fats are fully digested by lipases into fatty acids and glycerol

Question 22

digestion example: cheese sandwhich and juice

Answer 22

1) mouth, chewing breaks down the food into smaller pieces
- starch present in the sandwich is partially digested by carbohydrases present in the saliva
- juice passes through mouth to the gullet
2) gullet
- chemical digestion of starch continues in the gullet as food is mixed with the saliva
- juice and pieces of the sandwich pass through the gullet into the stomach
3) stomach:
- cheese sandwhich is broken down into smaller piece through churning
- proteins present in the sandwich are partially digested by proteases present in gastric juice formed
4) small intestine:
- cheese sandwich and orange juice if fully digested here:
carbohydrates -> simple sugar
- protein -> amino acids
- fats -> fatty acids
- small soluble molecules of digested food are absorbed
5) large intestine: water and mineral salts are absorbed to the bloodstream
6) rectum: fibres in orange juice and indegistble waste from faeces which are temporarily stored
7) faeces are released through the anus

Question 23

where do the digested food go

Answer 23

absorbed into the blood, which carries the molecules around the body, used for different purposes

Question 24

simple sugars, fatty acids and glycerol, and amino acids are used for::::

Answer 24

1) resperiation to release energy, allowing cells to carry out functions to grow 2) make fats in the body 3) raw material to repair tissue and body grow

Question 25

how does diabetes occur

Answer 25

we consume more carbohydrates than what our body needs

Question 26

diabetes is when

Answer 26

the blood sugar level is too high - produce insufficient insulin, which is supposed to regulate blood sugar level

Question 27

symptoms of diabetes

Answer 27

- slow healing of wounds - blurry vision - frequent urination

Question 28

issues that affect human digestive system

Answer 28

- constipation - gastric pain - food poisoning

Question 29

constipation

Answer 29

- faeces moves through large intestine very slowly - too much water is absorbed, making the faeces hard and dry

Question 30

causes of constipation

Answer 30

- stress - not enough fibre - not drinking enough water - not have adequate exercise

Question 31

gastric pain

Answer 31

gastritis: painful swelling/inflamation of stomach lining

Question 32

symptoms of gastritis

Answer 32

- upper abdominal pain - nausea - bloating

Question 33

cause of gastritis

Answer 33

- bacteria - virus - skipping meals - too much caffeine - too much oily food

Question 35

food poisoning