B3

Question 1

what is a catalyst?

Answer 1

a substance that increases the speed of a reaction w/o being changed or used up

Question 2

what is an enzyme?

Answer 2

catalystnmade by living organisms
- biological catalysts

Question 3

what is an active site?

Answer 3

complimentary to substrate causing it to be specific

Question 4

where does photosynthesis happen?

Answer 4

in the leaves
chloroplasts

Question 5

what factors affect photosynthesis?

Answer 5

temperature, light intensity, carbon dioxide concentration

Question 6

what happens to the RoP if light increases?

Answer 6

it increases then plateuas

Question 7

what happens if RoP plateuas

Answer 7

something else is the limiting factor

Question 8

What happens to RoP if temperature is ow

Answer 8

enzymes work more slowly

Question 9

What factors affect enzyme action?

Answer 9

temperature, pH and substrate concentration

Question 10

wha happens to enzyme action if:
temp is too high
temp is too low

Answer 10

high: enyme denatures
low: denatures, not enough energy

Question 11

what happens to enzyme aaction if
ph is too high
ph is too low

Answer 11

denatures for both

Question 12

what happens to enzyme rate of reaction if substrate concentration is too high or low

Answer 12

high: rate of reaction increases until plateaue
low: rate of reaction decreases

Question 13

what is diffusion?

Answer 13

net movement of particles from area of low to high concentration

Question 14

what does it mean if the cell membrane is partially permeable?

Answer 14

only some molecules can diffuse that are small enough
- water, glucose, amino acids

Question 15

is duffusion passive or active?

Answer 15

passive, it doesnt r3equire energy from cell

Question 16

what is osmosis?

Answer 16

net movement of water molecules across a partiallly permeable membrane from a region of low to high concentration

Question 16

what is osmosis?

Answer 16

net movement of water molecules across a partiallly permeable membrane from a region of low to high concentration

Question 17

what determines water concentration

Answer 17

the proportion of water to solutes

Question 18

what is acyive transport?

Answer 18

movement of molecules against their concentration gradient

Question 19

is active transport active or passive?

Answer 19

active, it requires energy from cell

Question 20

how do mitochondria absorb mineral ions?

Answer 20

active transport

Question 21

why cant plants absorb mineral ions by diffusion?

Answer 21

their concentration is higher in the root hair cell than the soil

Question 22

organ system of a plpant

Answer 22

root, stem and leaves

Question 23

what is the site of photosynthesis?

Answer 23

leaves

Question 24

what is a stomata?

Answer 24

holes in the leaf

Question 25

how does CO2 travel

Answer 25

lowwer epidermis(stomata), spongy mesophyll(gaps to diffuse), palisade mesophyll(most of photosynthesis lots of chloroplasts), upper epidermis(almost transparent)

Question 26

how do plants reduce water loss?

Answer 26

waxy cuticle

Question 27

what are the stomata?

Answer 27

openings of gurad cells

Question 28

why do stomata open for as short as possible?

Answer 28

to minimise water loss but maximise CO2 absorption

Question 29

why do guard cells get turgid?

Answer 29

turgid is when they are swollen with water and this is when the stomata open

Question 29

why does the guard cells get flaccid?

Answer 29

flaccid is low on water and limp and they close

Question 30

when do stomata close automatically?

Answer 30

when water supplies dry up and they are sensitive to light and close at night to save water

Question 30

what cells carry out translocation?

Answer 30

phloem

Question 31

what helps the movement of substances in the phloem?

Answer 31

holes inbetween cells

Question 32

what direction does the phloem carry things in?

Answer 32

any direction

Question 33

what does the phloem do?

Answer 33

translocates sugar from photosynthetic tissues to non photosynthetic issue - leaves to roots

Question 34

how does sugar enter the phloem?

Answer 34

through active transport and pushed by water that enters through osmosis

Question 35

what is the zylem made from?

Answer 35

dead cells with no ends

Question 36

structure of xylem

Answer 36

one long hollow tube

Question 37

what direction does the mineral ions and waater travel in?

Answer 37

up

Question 38

what are xylem walls strengtheed in ?

Answer 38

lignin

Question 39

what does the xylem do?

Answer 39

transports water and mineral ions from roots to leaves

Question 40

what is transpiration?

Answer 40

the evaporation of water from leaves

Question 41

what affects transpiration rate?

Answer 41

light intensity, temoerature, air movement

Question 41

what affects transpiration rate?

Answer 41

light intensity, temoerature, air movement

Question 42

how do plants get healty?

Answer 42

by absorbing mineral ions

Question 43

how do plants absorb mineral ions? diffusion, active transport or osmosis?

Answer 43

active transport as there is a high concentration of mineral ions in root hair cells that soil

Question 44

what does a lack of magnesium lead to?

Answer 44

yellow leaves as magnesium makes chlorophyll

Question 45

hat does a lack of nitrates lead to?

Answer 45

stunted growth as there is a lack of amino acids coding for protein

Question 46

what are carbohydrates, lipids and proteins?

Answer 46

biological molecules and nutrients

Question 47

carbohydrates

Answer 47

* made of C, H, O * single sugars can join together to make complex carbohydrates * broken down by enxzymes in mouth and small intestine

Question 48

proteins

Answer 48

* made of long chains of amino acids * made of C, H, O, N * broken down in stokmach and small intestine

Question 49

lipids

Answer 49

* made of C, H, O * both fats and oils - dependent on temp * contain single glycerol mcl attached to fatty acid mcls * not polymers- monomers * broken down in small intestine

Question 50

how do you test fror sugars?

Answer 50

benedicts * heat in water bath

Question 51

what color will positive benedicts turn?

Answer 51

green, yellow, red

Question 52

how do you test for starch?

Answer 52

iodine

Question 53

what colour will opositive iodine be?

Answer 53

blueish black

Question 54

how do you test for lipids?

Answer 54

ethanol/ emulsion test

Question 55

what happens if there is lipids present?

Answer 55

milky emulsion forms

Question 56

how to test for proteins?

Answer 56

bieurets * sodium hydroxide and copper sulphate

Question 57

how happens if proteins are present?

Answer 57

solution turns purple

Question 58

what happens in the water cycle?

Answer 58

- energy causes water to evaporate - water vapour condenses in clouds then water falls back as rain - cycle starts again

Question 58

what happens in the water cycle?

Answer 58

- energy causes water to evaporate - water vapour condenses in clouds then water falls back as rain - cycle starts again

Question 59

what happens in the carbon cycle?

Answer 59

- photosynthesis means CO2 goes into plants which get eaten by animals or passed into atmos - when organism die, they decay and release CO2 into the atmos or become fossil fuels which gets burnt by humans

Question 60

what is a population?

Answer 60

all organisms of one speiceis in a habitat

Question 61

what is a community?

Answer 61

all organisms in one habitat

Question 62

what is an ecosystem?

Answer 62

community of organisms and abiotic conditions

Question 63

what is meant by biotic?

Answer 63

living factors such as food, number of predators and competion

Question 64

what is meant by abiotic

Answer 64

non living factors such as temperature, soil ph and mineral content

Question 65

what is interdependence?

Answer 65

all species depend on other species in someway so if something happens to one species, if affects the whole ecosystem

Question 66

what is eutraphication?

Answer 66

when a body of water becomes enriched with minerals - lading to rapid growth of algae whcih builds up on water, blocking sunlight which affects rate of oxygen in water, causing fish and plants to die

Question 67

what is a potometer used for?

Answer 67

to measure the rate of transpiration thats proportional to water uptak

Question 68

w can you measure the ecosystem?