unit 5

Question 1

what is a photosystem

Answer 1

a complex of membrane proteins embedded with photosynthetic pigments in them for example chlorophyll in the thylakoid membrane

Question 2

photoionisationin non cyclic photophosphyralation

Answer 2

1) light is absorbed by the chlorophyll in photosystem one in the thylakoid membrane
the electrons reach a higher energy level this causes them to leave the chlorophyll this is called photoionization. the chlorophyll is now a positive ion

Question 3

chemiosmotic theory in non cyclic

Answer 3

the chemiosmotic theory states that the transfer of electrons down an electron transport system through a series of oxidation-reduction reactions releases energy. This energy allows certain carriers in the chain to transport hydrogen ions (H+ or protons) across a membrane

Question 4

non cyclic photophosphorylation- how is ATP made

Answer 4

the electrons move through a series of redox reactions down the electron carriers which produces energy, which is used to actively transport hydrogen ions from the stroma to the thylakoid lumen
this creates a electrochemical gradient.
the hydrogen ions go through facilitated diffusion. through the enzyme ATP synthase, which causes atp synthase to change shape and its this change in shape which produces the energy to ctatlyse thr formation of ATP

Question 5

non cyclic photophosphorylation- how is reduced NADP made

Answer 5

the electrons move through a series of redox reactions down the electron carriers which produces energy, which is used to actively transport hydrogen ions from the stroma to the thylakoid lumen
this creates a electrochemical gradient.
but is absorbed by photosystem one and they are trasnferred to the coenzyme NADP along with hydrogen ions to form reduced nadph

Question 6

cyclic photophosphylation

Answer 6

when there is an excess amount of of NADPH the electrons are passed back around the electron trasnport system and only produce a small amount of ATP until there is available NADP to accept the elctrons

Question 7

5 ATP properties

Answer 7

1. ATP cant pass out of the cell, so the cell always has an immediate energy source
2. ATP can be regenerated easily, it can be hydrolysed easily
3. ATP is small and soluble so it can go to any part of the cell
4. it can phosphorylate molecules, making them more reactive by adding an inorganic phosphate
5. releases a small amount of manageable energy so it is not dissipated as heat and

Question 8

The compensation point

Answer 8

there is a certain light intensity where the rate of respiration matches the rate of photosynthesis, oxygen is being used up at the same rate its being produced this is called the compensation point

Question 9

What are the two stages in photosynthesis

Answer 9

light dependant reaction and light independent reaction

Question 10

photoionisation is used for what three things

Answer 10

1. making ATP from ADP plus pi
2. making reduced NADP from NAD
3. Photolysis, 1/2 ,O2 and electrons to replace the lost ones from photoionisation

Question 11

The light dependant contains two types

Answer 11

cyclic and non cyclic

Question 12

what is the calvin cycle

Answer 12

light independent reaction

Question 13

what are the three stages of the calvin cycle

Answer 13

1. formation of GP
2. Formation of TP
   3.regenerationn of ribulose biphosphate or hexose sugars

Question 14

formation of glycerate 3 phosphate In PS

Answer 14

1x carbon molecule from the atmosphere and RuBp, catalysed with rubisco to form a 6 carbon compound molecule which is unstable so it breaks down to X2 GP

Question 15

formation of triose phosphate in PS

Answer 15

NADP becomes oxidised and X2 GP becomes reduced using ATP from the light dependent reaction

Question 16

regeneration of ribulose biphosphate in PS

Answer 16

5/6th is regenerated into RuBp other 1/6 is made into hexose sugars

Question 17

how much turns of the calvin cycle to produce glucose

Answer 17

it will take 6 turns for to turn into 1/2

Question 18

what are the four optimum conditions for photosynthesis

Answer 18

1. light intensity at a certain wavelength
2. temperatures
3. carbon dioxide
4. water

Question 19

high light intensity of a certain wavelength

Answer 19

light is needed for the light dependant reaction in photosynthesis
chlorophyll only absorbs red and blue light, certain wavelengths of light

Question 20

temperatures

Answer 20

temperature is too low that enzymes like ATP synthase and Rubisco become inactive, photosynthesis cant take place
if the temperature is too high then the enzymes become denatured
and if its too high the stomata can close to prevent dehydration but that means the carbon dixoide concentration decreases

Question 21

carbon dioxide

Answer 21

if co2 levels increase so does the rate of photosynthesis but if it is too high the stomata may close

Question 22

water

Answer 22

if there is too less water, then photosynthesis cant take place
but if too much the plant can be waterlogged and decrease the uptake of important minerals such as magnesium which is used to make chlorophyll a

Question 23

what are the three limiting factors for photosynthesis

Answer 23

carbon dioxide
light intensity
temperature

Question 24

Increasing plant growth

Answer 24

in agriculture farmers increase plant growth by maintaining the optimum conditions for plants in a glasshouse for example

Question 25

How does chromatography work

Question 26

investigating dehydrogenase activity in chloroplasts

Question 27

aerobic vs anaerobic respiration

Question 28

what are the four steps in aerobic respiration

Question 29

2 stages in glycolysis with explanation

Question 30

products of glycolysis

Question 31

products of glycolysis in anaerobic respiration

Question 32

the link reaction

Question 33

products released from link reaction

Question 34

3 stages in the krebs cycle

Question 35

krebs cycle: formation of 6 carbon compound

Question 36

krebs cycle: formation of 5 carbon compound

Question 37

regeneration of oxaloacetate

Question 38

products of the krebs cycle

Question 39

oxidative phosphorylation

Question 40

mitochondrial disease

Question 41

investigating factors affecting respiration in single celled organisms

Question 42

respirometer to measure oxygen consumption