Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

biology paper 2 > topic 5 (photosynthesis) > Flashcards

topic 5 (photosynthesis) Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what is photosynthesis?

A

the process where energy from light is used to make glucose from water and carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the word equation for photosynthesis?

A

carbon dioxide + water = glucose + oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the chemical equation for photosynthesis?

A

6CO2+6H2O=C6H12O6+6O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

where does photosynthesis take place?

A

in the chloroplasts of plant cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is a chloroplast?

A

flattened organelle surrounded by a double membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what do thylakoid membranes stack to form?

A

grana

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are grana linked by?

A

lamellae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what photosynthetic pigments do chloroplasts contain?

A

chlorophyll a
chlorophyll b
carotene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a photosynthetic pigment?

A

coloured substances that absorb the light energy needed for photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

where are photosynthetic pigments found?

A

in the thylakoid membranes attached to proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a photosynthetic pigment attached to a protein called?

A

photosystem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what wavelength does photosystem I best absorb light at?

A

700nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what wavelength does photosystem II best absorb light at?

A

680nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the stroma?

A

gel like substance containing enzymes, sugars and organic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what happens to carbohydrates produced by photosynthesis that are not used straight away?

A

stored as starch grains in the stroma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the two stages of photosynthesis?

A

light dependent reaction

light independent reaction

17
Q

where does the light dependent reaction occur?

A

in the thylakoid membranes

18
Q

what is the energy in the light dependent reaction used by?

A

making ATP
making reduced NADP
photolysis

19
Q

what are the two types of photophosphorylation in the light dependent reaction?

A

non cyclic and cyclic

20
Q

what are the stages of non cyclic photophosphorylation?

A

light energy is absorbed by PSII

light energy excites electrons in chlorophyll

electrons move to a higher energy level

high energy electrons released from chlorophyll move down the electron transport chain to PSI

excited electrons from chlorophyll leave PSII to move down the electron transport chain (but these must be replaced)

light energy splits water into protons, electrons and oxygen during photolysis

excited electrons lose energy as they move down the electron transport chain

energy used to transport protons into the thylakoid so it has a higher concentration of protons than the stroma= proton gradient

protons move down their concentration gradient into the stroma via ATP synthase, which synthesises ATP

light energy absorbed by PSI excites the electrons to a higher energy level

electrons transferred to NADP with a proton from the stroma to produce reduced NADP

21
Q

what happens in cyclic photophosphorylation?

A

only uses PSI

electrons from chlorophyll passed back to PSI by electron carriers

electrons recycled and repeatedly flow through PSI

produces small amounts of ATP

22
Q

where does the light independent reaction occur?

A

in the stroma

23
Q

what are the stages of the light independent reaction?

A

CO2 enters the leaf via the stomata and diffuses into the stroma

combined with ribulose bisphosphate, catalysed by the enzyme rubisco

produces unstable 6C compound- broken down into 2 3 carbon compounds= glycerate 3 phosphate

hydrolysis of ATP ,and H+ ions from reduced NADP, provides energy to change glycerate 3 phosphate into triose phosphate

some converted into useful organic compounds, some continues in the Calvin Cycle to regenerate ribulose biphosphate

24
Q

what useful organic substances do triose phosphate and glycerate 3 phosphate make?

A

carbohydrates
lipids
amino acids

25
Q

how is the Calvin Cycle used to make carbohydrates?

A

hexose sugars made by joining 2 triose phosphate molecules

larger carbohydrates made by joining hexose sugars together

26
Q

how is the Calvin Cycle used to make lipids?

A

made using glycerol (which is synthesised by triose phosphate), and fatty acids (which are synthesised by glycerate 3 phosphate)

27
Q

how is the Calvin Cycle used to make amino acids?

A

some amino acids are made from glycerate 3 phosphate

28
Q

how many turns of the Calvin Cycle are needed to make 1 hexose sugar?

A

6

29
Q

how many triose phosphate molecules are used to regenerate ribulose biphosphate?

A

5/6

30
Q

how many triose phosphate molecules are needed to form 1 hexose sugar?

A

2

31
Q

how many ATP do 6 turns of the Calvin Cycle need?

A

18

32
Q

how many reduced NADP do 6 turns of the Calvin Cycle need?

A

12

33
Q

what are the idea conditions for photosynthesis?

A

high light intensity of a certain wavelength

temperature around 25C

carbon dioxide at 0.4%

34
Q

why is photosynthesis best at 25C?

A

if below 10C/above 45C, enzymes begin to denature

at high temperatures, stomata close to avoid losing too much water, which slows photosynthesis as less stomata can enter

35
Q

what is usually the limiting factor for photosynthesis on a warm, sunny, windless day?

A

carbon dioxide

36
Q

what is usually the limiting factor for photosynthesis at night?

A

light intensity

37
Q

how can farmers manage carbon dioxide concentration in a greenhouse?

A

carbon dioxide added to the air, eg) by burning a small amount of propane in a CO2 generator

38
Q

how can farmers manage light intensity in a greenhouse?

A

light can get in through the glass

lamps provide light at night time

39
Q

how can farmers manage temperature in a greenhouse?

A

the glass traps heat energy from sunlight, which warms the air

heaters and cool systems keep a constant optimum temp

air circulation can be used to make sure the temperature is even throughout the greenhouse

biology paper 2 (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions