Key Concepts

Question 1

Eukaryotic cell

Answer 1

Has a nucleus

Question 2

Prokaryotic cell

Answer 2

Has no nucleus

Question 3

Sub cellular structures in animal cell

Answer 3

Nucleus
Cell membrane
Mitochondria
Ribosomes

Question 4

Sub cellular structures in plant cells

Answer 4

Nucleus
Cell membrane
Cell wall
Chloroplasts
Mitochondria
Vacuole
Ribosomes

Question 5

Sub cellular structures in bacteria cell

Answer 5

Chromosomal DNA
Plasmid DNA
Cell membrane
Ribosomes
Flagella

Question 6

Specialised cells examples

Answer 6

Sperm
Egg
Ciliates epithelial

Question 7

How is sperm adapted

Answer 7

Acrosome
Haploid nucleus
Mitochondria
Tail

Question 8

How is egg adapted

Answer 8

Nutrients in cytoplasm
Haploid nucleus
Changes in cell membrane after fertilisation

Question 9

Light microscope

Answer 9

Uses light and it’s greatest possible magnification is around x2000

Question 10

Electron microscopes

Answer 10

Uses electrons, can view object up to around x10 million

Question 11

Why is electron microscope better

Answer 11

Can see cell structures and organelles more clearly

Question 12

Pico

Answer 12

(10^-12)

Question 13

Milli

Answer 13

(10^-3)

Question 14

Nano

Answer 14

(10^-9)

Question 15

Micro

Answer 15

(10^-6)

Question 16

What are enzymes

Answer 16

Biological catalysts

Question 17

Enzymes have to be _____ to their substrate

Answer 17

Specific

Question 18

3 factors that affect enzyme activity

Answer 18

Temperature
Substrate concentration
pH

Question 19

Why do enzymes have to be specific

Answer 19

So that the substrate is able to fit into the active site of the enzyme

Question 20

What happens when an enzyme is denatured

Answer 20

The active site changes shape and therefore the substrate cannot fit

Question 21

What happens with enzymes at low temperatures

Answer 21

Molecules move more slowly so the reaction is slower as it takes longer for the substrate to fit into active site

Question 22

What is the optimum temperature

Answer 22

The point at which the enzyme works at its fastest rate

Question 23

What does adding more substrate cause to happen

Answer 23

Increases rate of reaction

Question 24

Why is there a limit to the amount of substrate that speeds the reaction

Answer 24

Eventually the active site of every enzyme will be busy

Question 25

Optimum temperature for enzymes to work at (usually)

Answer 25

37C

Question 26

Why does pH affect enzyme activity

Answer 26

Can change shape of active site

Question 27

What is enzymes sole purpose

Answer 27

Break down large molecules into smaller ones, so they can be in the bloodstream

Question 28

What enzymes digests carbohydrates

Answer 28

Amylase

Question 29

What does amylase do

Answer 29

Digest carbohydrate (eg starch) into sugar (eg glucose)

Question 30

Enzyme that digests lipids

Answer 30

Lipase

Question 31

What does lipase do

Answer 31

Digest lipids (eg energy storage) into fatty acids/glycerol (eg for respiration)

Question 32

What enzyme digests proteins

Answer 32

Protease

Question 33

What does protease do

Answer 33

Digest protein (eg for muscle cells) into amino acids (eg to make enzymes)

Question 34

What does it mean that an enzyme is a catalyst

Answer 34

It speeds up the reaction but is not used

Question 35

What does iodine test for and how

Answer 35

Starch If present - blue black If not present - yellow/orange

Question 36

What does Benedicts solution test for and how

Answer 36

Sugar If present - green>orange>red (depend on how much sugar) If not present - blue

Question 37

Wha does biuret test test for and how

Answer 37

Protein If present- pale purple If not present- pale blue

Question 38

What does ethanol test for and how

Answer 38

Fat If present- cloudy If not present - clear

Question 39

What is diffusion

Answer 39

High concentration of molecules moves to a low concentration Eg gaseous exchange

Question 40

What is active transport

Answer 40

Low concentration of molecules to a high concentration | Eg roots absorb nutrients from soil

Question 41

What is osmosis

Answer 41

Movement of water from high concentration to low