Biol4 3

Front 1

How is a leaf adapted to photosynthesis?

Back 1

Large SA to collect usnlight

arrangement to minimise overlapping

thin so short diffusion distance

transparent upper epidermis and cuticle

air spaces for diffusion

xylem

stomata that open when light is intense

long narrow upper mesophyll cels packed with chloroplasts

Front 2

Why is it important that the photolysis of water occurs?

Back 2

Chlorophyll continues to absorb light neergy and to reduce NADP

Front 3

Describe what happens in the LDR

Back 3

Light absorbed by chlorophyll molecule;

molecule is excited, and pair of electrons in molecule gain energy and leave the molecule;

electrons taken up by electron carriers in transport system;

in thylakoid membrane;

lose energy as electrons transferred;

used to make ATP by photophosphorylation;

NADP reduced by electrons and hydrogen ions

from photolysis of water;

Front 4

How are chloroplasts adapted to the LDR?

Back 4

Thylakoid membranes provide a large surface area for the attachment of proteins/carriers

proteins hold chlorophyll in place

chloroplast has DNA and ribosomes to manufacture proteins when necessary

Front 5

Describe what happens in the LIR

Back 5

CO2 diffuses into leaf through stomata;

combines with RuBP catalysed by Rubisco;

2*GP formed;

reduced into TP;

using reduced NADP and ATP;

TP is a sugar;

used to make glucose/triglycerides/phospholipids/proteins;

and regenerate RuBP;

USING ATP;

Front 6

How are chloroplasts adapted to the LIR?

Back 6

Stroma contain all enzymes needed

DNA and ribosomes to manufacture enzymes

stroma has grana, so products readily diffuse

Front 7

In the lollipop experiment, how are the products in methanol separated?

Back 7

2-way chromatography

Front 8

What is the law of limiting factors/how do you identify the limiting factor?

Back 8

Factor which is at its least favourable value/in shortest supply

increasing increases the rate of photosynthesis

Front 9

What is the compensation point?

Back 9

point at which no net exchange of gases into or out of the plant

Front 10

Why does temp affect rate of photosynthesis?

Back 10

Increases rate of LIR due to enzyme involvement

Front 11

Why is measuring the volume of oxygen produced by pondweed not reflective of rate of photoysnthesis? How do you overcome this?

Back 11

Some oxygen used in respiration/dissolved in water - actually measuring how much photosynthesis exceeds respiration;

measure rate of oxygen taken up in dark

Front 12

How can you control CO2 conc + temp + water

Back 12

Burn fossil fuel

heater

spray/irrigate

Front 13

What does anaerobic resp produce?

Back 13

Ethanol and CO2 in plants and yeast

lactate in animals

Front 14

Describe the process of glycolysis.

Back 14

Hexose sugar split into pyruvate;

activation of glucose by phosphorylation - addition of 2 phosphate molecuels makes it more reactive and lowers activation energy;

splitting into triose phosphate;

TP oxidised to produce 2*NADH

2*ATP produced per TP into pyruvate

Front 15

Where does glycolysis occur?

Back 15

The cytoplasm of cell

Front 16

What is the overall yield from glycolysis?

Back 16

2 ATP, 2 NADH, 2 pyruvate

Front 17

Describe what happens in the link reaction

Back 17

Pyruvate actively transported into matrix of mitochondria;

it is oxidised into CO2 and acetate/ethanoic acid producing one NADH

combines with acetylcoA to be used in Krebs/be right shape for enzyme

Front 18

Describe what happens in the Krebs cycle

Back 18

AcetylcoA combines with 4C molecule to form citric acid;

undergoes oxidative, decarboxylation, losing 2 CO2 molecules and reducing 3 NAD and 1 FAD;

ATP produced by substrate-level phosphorylation;

4C regenerated

Front 19

What is the importance of the Krebs cycle?

Back 19

Breaks macromolecules into smaller ones ;

source of intermediates, fatty acids and amino acids;

produced reduced coenzymes with potential to produce ATP;

regenerates 4C to prevent acetylcoA from accumulating

Front 20

What is a coenzyme?

Back 20

A molecule required for the function of particular enxzymes - carry hydrogens and electrons

Front 21

How does NAD oxidise stuff?

Back 21

Acts as coenzyme

with dehydrogenase enzymes to remove hydrogen ions and electrons

Front 22

What is the importance of the Krebs cycle?

Back 22

Source of intermdiates - amino acids, faty acids

breaks down macromolecuels (acetate into CO2)

produces reduced coenzymes with potential to make ATP

regenerates 4C compound and prevents acetylcoA from accumulating

Front 23

Describe what happens in the electron transport chain?

Back 23

Reduced NAD and reduced FAD donate electrons to electron carriers in cristae of mitochondria

electrons passed through chain via redox reactions

lose energy used to pump H+ ions into inter-membranal space

H+ions diffuse down gradient into matrix, passing through ATPase

Electrons and hydrogen ions combine with oxygen, terminal electron acceptor

Front 24

How does cyanide = death?

Back 24

non-competitively Inhibits enzyme that combines oxygen electrons and hydrogen ions, so 'backs up' chain

Front 25

What happens to lactate if oxygen is available again?

Back 25

Oxidised into pyruvate

oxidised further to release energy

or converted into glycogen by liver cells

Front 26

What is the advantage of anaerobic respiration?

Back 26

overcome temp shortage of oxygne

regenerate NAD to allow glycolysis to continue

Front 27

what are the differences between aerobic and anaerobic resp?

Back 27

Aerobic is slower

produced more ATP

does not produce lactate

takes place in mitochondria

Front 28

Why do muscle cells carry out anaerobic resp?

Back 28

Use up oxygen faster than supplied

Front 29

Which plant cells carry out anaerobic resp?

Back 29

Root hair cells in waterlogged soils