Chapter B3 - Organisation and the digestive system

Question 1

differentiate

Answer 1

process where cells become specialised for a particular function

Question 2

tissue

Answer 2

group of specialised cells with a similar structure and function

Question 3

organs

Answer 3

an aggregation of different tissues working together to carry out specific functions

Question 4

organ system

Answer 4

group of organs that work together to carry out specific functions and form organisms

Question 5

digestive system

Answer 5

organ system where food is digested and absorbed

Question 6

enzymes

Answer 6

biological catalysts, usually proteins

Question 7

carbohydrates and where are they found

Answer 7

• molecules that contain only carbon, oxygen and hydrogen. they provide energy for the metabolism
• found in foods such as rice, potatoes, and bread

Question 8

simple sugars and e.g.

Answer 8

• small carbohydrate units,

- e.g. glucose

Question 9

lipids- e.g. and reactants

Answer 9

• include fats and oils and are found in food such as butter, olive oil, and crisps.
• they are made from carbon, hydrogen and oxygen

Question 10

fatty acids

Answer 10

part of the structure of a lipid molecule

Question 11

glycerol

Answer 11

part of the structure of a lipid molecule

Question 12

proteins and uses

Answer 12

• molecules that contain carbon, hydrogen, oxygen, and nitrogen and are made from long chains of amino acids.
• used for building the cells and tissues of the body and to form enzymes.

Question 13

amino acids

Answer 13

• molecule made of oxygen, carbon, hydrogen and nitrogen,

- the building bocks of proteins

Question 14

denatured

Answer 14

breakdown of the molecular structure of a protein so it no longer functions

Question 15

catalysts

Answer 15

substance that speeds up the rate of another reaction but is not used up or changed itself

Question 16

active site

Answer 16

the site of an enzyme the the reactants bind

Question 17

metabolism

Answer 17

the sum of all the reactions taking place in a cell or the body of an organism

Question 18

amylase

Answer 18

enzyme that speeds up the digestion of starch into sugars

Question 19

lipase

Answer 19

enzymes that speed up the breakdown of lipids into fatty acids and glycerol

Question 20

bile

Answer 20

• neutralises stomach acid to give a high pH for the enzymes from the pancreas and small intestine to work well.
• not an enzyme

Question 21

main organs of the human digestive system (14)

Answer 21

• mouth
• gullet
• diaphragm
• liver
• gall bladder
• stomach
• bile duct
• duodenum
• pancreas
• small intestine
• large intestine
• appendix
• rectum
• anus

Question 22

3 types of tissue

Answer 22

muscular
glandular
epithelial

Question 23

muscular tissue function and function in stomach

Answer 23

contracts

churns content

Question 24

glandular tissue function and function in stomach

Answer 24

• produces substances e.g. enzymes and hormones

- digestive juices

Question 25

epithelial tissue function and function in stomach

Answer 25

• covers parts of the body

- covers outside and inside of stomach

Question 26

salivary and pancreas (glands) function

Answer 26

make + produce digestion juices containing enzymes to break down food

Question 27

liver (associated organ) function

Answer 27

produces bile

Question 28

stomach function

Answer 28

food is digested, enzymes break down large insoluble food molecules into smaller soluble ones

Question 29

small intestine function

Answer 29

soluble food molecules are absorbed into your blood

Question 30

large intestine function

Answer 30

water is absorbed from undigested food into blood

Question 31

what increases the effectiveness of an exchange surface?

Answer 31

• large surface area
• thin, for short diffusion path
• steep concentration gradient, achieved by having a good blood supply

Question 32

what is the surface area of small intestine increased by?

Answer 32

villi with an extensive network of microvilli to absorb product of digestion by diffusion and active transport

Question 33

where does carbohydrases and amylase act?

Answer 33

mouth and small intestine

Question 34

where does lipase act?

Answer 34

small intestine (bile provides alkali conditions and emulsifies fats)

Question 35

where does protease act?

Answer 35

stomach and small intestine

Question 36

what is the test for glucose and what colour is the end result?

Answer 36

Benedict’s test + heat, blue to green to red/brown

Question 37

what is the test for proteins and what colour is the end result?

Answer 37

Biuret test, lilac/purple

Question 38

what is the test for lipids and what colour is the end result?

Answer 38

Ethanol emulsion test, milky emulsion

Question 39

what is the test for starch and what colour is the end result?

Answer 39

Iodine solution test, blue-black

Question 40

give two main functions of the digestive system

Answer 40

• to digest food

- to absorb food molecules

Question 41

explain how the stomach is adapted to digest protein

Answer 41

• produces protease
• produces hydrochloric acid
• provides correct pH for enzyme to work