Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIOLOGY A2 > Photosynthesis > Flashcards

Photosynthesis Flashcards

1
Q

Why do plants need energy? (4)

A

⦾ Photosynthesis (1)
⦾ AT (1)
⦾ DNA replication (1)
⦾ Cell division (1)

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

Why do animals need energy? (4)

A

⦾ Muscle contraction (1)
⦾ Body temp maintenance (1)
⦾ DNA replication (1)
⦾ Cell division (1)

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

Photosynthesis equation? (1)

A

⦾ 6CO2 + 6H2O → C6H12O6 + 6O2 (1)

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

Why is photosynthesis an example of a metabolic pathway? (1)

A

⦾ Occur in small series of reactions (controlled by enzymes) (1)

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

Respiration equation? (1)

A

⦾ C6H12O6 + 6O2 → 6CO2 + 6H2O (1)

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

2 types of Respiration? (2)

Give the equations for the 2 different places the 2nd type occur? (2)

A

⦾ Aerobic - with Oxygen (1)
⦾ Anaerobic - with/o Oxygen (1)

  • Plants + Yeast → Ethanol + CO2 (1)
  • Humans → Lactate energy (1)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

ATP stands for? (1)

What is it? (1)

A

⦾ Adenosine TriPhosphate (1)

⦾ Store of energy (1)

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

ATP structure? (3)

A

⦾ Nucleotide base Adenine (1)
⦾ Ribose sugar (1)
⦾ 3 x Phosphate groups (1)

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

ATP properties?

A
  1. Stores/releases small energy amounts - reduce heat loss energy (1)
  2. Small soluble molecule - easily transported (1)
  3. Easily broken down - instantaneous energy release (1)
  4. Quickly remade (1)
  5. Phosphorylation - Added to other molecules to make more reactive by transferring 1 X its Pi groups (1)
  6. Can’t pass out cell - Always immediate energy supply (1)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where does photosynthesis occur? (1)

A

⦾ Chloroplast (1)

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

What are the different structures of chloroplast? (6)

A

⦾ Grana - Stacked thylakoid (1)
⦾ Lamellae - Link Grana (1)
⦾ Photosynthetic pigments (1) - Coloured substances that
absorb light energy
- Inside thylakoid membrane
e.g. Chlorophyll a/b
⦾ Photosystems - Protein + Pigment: PSI (700nm) + PSII (680nm) (1)
⦾ Stroma - contains enzymes + sugars (1)
⦾ Starch - Stored carbohydrates (1)

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

Explain ‘REDOX’? (3)

A

⦾ Reduction Is Gain of Electrons, Addition of H + Loss of O2 (1)
⦾ Oxidation Is Loss of Electrons, Loss of H + Gain of O2 (1)
⦾ Occurs simultaneously (1)

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

Define Coezymes and give an example? (1)

A

⦾ Molecules aid enzyme function (1)
⦾ by transferring chemical groups from one molecule to another (1)
e.g. NADP transfers H

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

Give a short summary of the Light-Dependent reaction?

7

A

⦾ Requires light (1)
⦾ Occurs: thylakoid membrane of chloroplasts (1)
⦾ Photoionisation occurs: (1)
⦾ Chlorophyll absorbs light energy → excites e-s (1)
⦾ High energy e-s released from chlorophyll (1)
⦾ Chlorophyll’s now a +ve ion (1)
⦾ Uses of the energy: ADP + Pi → ATP (1)
NADP → NADPH

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

Give a short summary of the Light-Independent reaction? (3)

A

⦾ Relies on LDR products (1)
⦾ Occurs: Stroma (1)
⦾ ATP + NADPH provide energy + H to make glucose (1)

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

Energy uses of Photoionisation? (3)

A

⦾ Photophosphorylation ADP + Pi → ATP (1)
⦾ NADP → NADPH (1)
⦾ Photolysis of water into: H+, Electrons + O2 (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are electron carriers? (1)

What do they do? (1)

A

⦾ Proteins linking photosystems (1)

⦾ Transfer electrons (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are electron transport chains? (1)

What flows through them?(1)

A

⦾ Photosystems + electron carriers (1)

⦾ excited electrons (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain fully the process of the Light-Dependent reaction/Non-cyclic photophosphorylation? (11)

A
  1. PSII absorbs light energy → excites e-s in chloropyll (1)
    2.Excited e-s move to higher energy level. (1)
  2. ## High energy e-s released from chlorophyll + move down ETC to PSI (1)
  3. Excited e-s which left PSII must be replaced. (1)
  4. Photolysis - light energy splits water into:
    ☉ H+, Electrons + O2 (H2O → 2H+ + 1/2O2) (1)
    ———————————————————————————
  5. Excited e-s lose energy moving down ETC + energy’s used to transport H+ to thylakoid + create higher proton (H+) conc in thylakoid than stroma. (1)
  6. Proton (H+) conc. grad. across thylakoid membrane (1)
  7. ## Protons (H+) move down conc. grad. into stroma via ATP synthase (1)
  8. ## Energy from movement combines ADP + Pi → ATP (1)
  9. PSI absorbs light energy + excites e-s to higher energy level(1)
  10. e-s transferred to NADP (and a H+) to form → NADPH (1)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Define chemiosmotic theory? (3)

A

⦾ Process of e-s flowing down ETC (1)
⦾ creating proton grad. across membrane to (1)
⦾ drive ATP synthesis. (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is Cyclic Photophosphorylation? (4)

A

⦾ ‘Cyclic’ - e-s from chlorophyll not passed onto NADP but back to PSI via e- carriers (1)
⦾ Only PSI used + ATP produced (1)
⦾ Therefore, e-s recycled + flow through PSI (1)
⦾ No NADPH/O2 produced - only small amounts of ATP (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What 2 products does the Light-Independent reaction require from the Light-Dependent reaction? (2)

A

⦾ ATP (1)

⦾ NADPH (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where does the Light-Independent reaction occur? (1)

A

⦾ Stroma (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the overall reaction for the Light-Independent reaction? (1)

A

⦾ RuBP (5C) + CO2 → TP (3C) (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why is the Light-Dependent reaction a ‘cycle’? (1)

A

⦾ RuBP regenerated (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What can the Light-Dependent reaction also be called? (1)

A

⦾ The Calvin Cycle (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q 
What do the following stand for/mean?
⦾ Rubisco (1)
⦾ GP (1)
⦾ RuBP (1)
⦾ TP (1)
A

⦾ Rubisco - enzyme (1)
⦾ GP - gylcerate-3-phosphate (3C) (1)
⦾ RuBP - Ribulose biphosphate (5C) (1)
⦾ TP - Triose phosphate (3C) (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The Light-Independent reaction/Calvin Cycle:

Explain the formation of glycerate-3-phosphate? (3)

A
  1. CO2 enters stomata + diffuses to stroma (1)
  2. Combines with RuBP and rubisco (1)
  3. Forms: unstable 6C compound which breaks down into 2 X GP (1)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the overall equation for the formation of gylcerate-3-phosphate? (1)

A

⦾ RuBP (5C) + CO2 + Rubisco → Unstable 6C compound → 2 X GP (3C) (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The Light-Independent reaction/Calvin Cycle:

Explain the formation of triose phosphate? (3)

A
  1. ATP from LDR hydrolised to provide energy to reduce
    GP → TP (1)
  2. NADPH is recycled to NADP to provide H+ for reaction (1)
  3. TP has many uses - glucose - regenerate RuBP (1)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The Light-Independent reaction/Calvin Cycle:

Explain the regeneration of ribulose biphosphate? (2)

A
  1. 5/6 TP molecules produced in reaction used to regenerate RuBP - which uses rest of ATP produced by LDR. (1)
  2. 1/6 molecules produced in reaction used for organic compounds e.g. hexose sugar (1)
32
Q

What are Hexose sugars? (1)

A

⦾ Simple 6C sugars (1)

⦾ Use to make larger carbohydrates (1)

33
Q

Explain how many times does the Calvin cycle need to turn to produce 1 hexose sugar? (7)

A

⦾ 6 X (1)
⦾ 3 X cycle produce 6 TP molecules (1)
⦾ 5/6 TP molecules used to regenerate RuBP (1)
⦾ 3 X cycle, only 1 TP molecule produced to make hexose sugar (1)
⦾ Hexose sugar has 6C so 2 TP needed to form 1 hexose sugar (1)
⦾ So cycle needs 6 X turn to produce 2 TP to be used for hexose sugar (1)
⦾ 6 turns need: 18 ATP + 12 NADPH from LDR (1)

34
Q

Explain the 4 optimum conditions for photosynthesis?

A
  1. High Light Intensity + Certain Wavelength:
    ⦾ Photosynthetic pigments a + b + carotene only absorb red + blue light in sunlight.
  2. 25C Temperature:
    ⦾ Photo… involves enzymes
    ⦾ > 10C - inactive
    ⦾ <45C - denatured
    ⦾ High temps → stomata close to retain water
    ⦾ Causes photo… to slow down because less CO2 enters leaf when stomata close.
  3. CO2 at 0.4%:
    ⦾ In air, CO2 = 0.04% gases in atm
    ⦾ Increase to 0.4%, increase rate
    ⦾ But any higher, stomata close
  4. Constant water supply:
    ⦾ Too little → Photo… stops
    ⦾ Too much → Waterlogged soil and decreased uptake of minerals
35
Q

Why do farmers try to create the optimum condition environment for their plants? (3)

A

⦾ Supply plant’s needs (1)
⦾ Increase growth (1)
⦾ Increase yield (1)

36
Q

How do farmers create optimum conditions in glasshouses? (5)

A
  1. CO2 conc.
    ⦾ Burn propane in CO2 generator (1)
  2. Light
    ⦾ Light through glass (1)
    ⦾ Lamps at night (1)
    ⦾ Red + Blue lights maximise photosynthesis (green reflected by plants)
  3. Temperature:
    ⦾ Glasshouses trap heat from sunlight → warms air (1)
    ⦾ Heaters + coolers maintain optimum temp + air circulation maintains even temp throughout glasshouse (1)
37
Q

What is a limiting factor? (1)

A

⦾ Variable that can slow down ROR (1)

38
Q

What are the limiting factors of photosynthesis? (3)

A

1 ⦾ Light (1)
2 ⦾ Temperature (1)
3 ⦾ CO2 (1)
⦾ ALL need to be at good level

39
Q

On what type of day is CO2 usually the limiting factor?

A

⦾ Warm, sunny windless day (1)

40
Q

At which time of day is light intensity usually the limiting factor? (1)

A

⦾ Night (1)

41
Q

What is ‘the saturation point’? (1)

A

⦾ Factor no longer limits reaction + something else has become the limiting factor

42
Q

What does it mean when a graph begins to level off?

for limiting factors in photosynthesis) (2

A

⦾ Doesn’t mean photosynthesis has stopped (1)

⦾ Rate of photosythesis isn’t increasing anymore (1)

43
Q

Chromatography experiment:

Chromatography purpose? (1)

A

⦾ Separates mixtures to identify components (1)

44
Q

Chromatography experiment:

What is the mobile phase? (2)

A

⦾ Molecules can move (1)

⦾ In paper + thin-layer chromatography, it’s a liquid solvent (1)

45
Q

Chromatography experiment:

What is the stationary phase? (3)

A

⦾ Molecules can’t move (1)
⦾ Paper: chromatography paper (1)
⦾ Thin-layer: thin layer of solid on TLC plate (1)

46
Q

Chromatography experiment:

What are the basic principles of chromatography? (3)

A

⦾ Mobile phase moves over stationary phase
⦾ Components in mixture spend different amounts of time in mobile + stationary phase
⦾ Components thats spend longer in mobile phase travel faster/further. Time spent in different phases is what separates out different components of mixture

47
Q

Chromatography experiment:

What is the pattern of spots you end up with called?

A

⦾ Chromatogram

48
Q

Chromatography experiment:

Plants contain different photosynthetic pigments in their leaves. Each pigment absorbs…

A

⦾ …different wavelengths of light

49
Q

Chromatography experiment:

Having more than 1 type of pigment in a leaf increases…

A

⦾ …range of wavelengths of light plant can absorb

50
Q

Chromatography experiment:

Different plants species contain different proportions and mixtures of…

A

⦾ …pigments

51
Q

Chromatography experiment:

What is an Rf value?

A

⦾ Distance a substance has moved from through stationary phase in relation to solvent.

52
Q

Chromatography experiment:

Each pigment has a specific ___ values under specific ________.

A

⦾ Rf

⦾ Condtions

53
Q

Chromatography experiment:

Explain the method for how to use TLC to compare pigments present in shade-tolerant and shade-intolerant plants?`

A

1 ⦾ Grind up leaved from shade-tolerant plant being investigated with anhydrous Na2SO4.
2 ⦾ Add a few drops of propanone
3 ⦾ Transfer liquid to test tube and add petroleum ether
4 ⦾ Gently shake tube
5 ⦾ 2 distinct layers form in liquid - top layer is pigment mixed in with petroleum ether.
6 ⦾ Transfer some of liquid from top layer into 2nd test tube with anhydrous Na2SO4
7 ⦾ Draw horizontal line near bottom of TLC plate
8 ⦾ Build a concentrated spot of liquid of 6 ⦾ on the line.
9 ⦾ Do this by: applying several drops, ensuring each one is dry before next is added - point of origin.
10 ⦾ When plate’s completely dry, place plate in small container with prepared solvent - just enough so point of origin is little above solvent
11 ⦾ Place lid on container + leave plate to develop
12 ⦾ As solvent spreads up plate, different pigments move with it but at different rate - therefore separate.

54
Q

Chromatography experiment:

What do you do after the different pigments have separated out?

A

1 ⦾ Take plate out + mark solvent front with pencil

2 ⦾ Leave plate to dry in well-ventilated place

55
Q

Chromatography experiment:

What is the equation for calculating Rf values?

A

⦾ Rf B Distance travelled by spot
value = —— = ——————————————
A Distance travelled by solvent

56
Q

Chromatography experiment:

What is the solvent front?

A

⦾ The furthest point the solvent has reached

57
Q

Chromatography experiment:

What are the top layer of the 2 distinct layers that form?

A

⦾ The pigment mixed in with the petroleum ether

58
Q

Chromatography experiment:

What is the point of origin?

A

⦾ The point on the line of several drops of the final pigment which separate out.

59
Q

Chromatography experiment:
What are the health + safety aspects to consider?
(4 marks)

A

1 ⦾ The chromatography solvent e.g. propanone or petroleum ether are toxic and highly flammable
2 ⦾

60
Q

Chromatography experiment:

gsdfdjsgf

A

hdskhfkjdshbgjl

61
Q

Chromatography experiment:

hsjdfch\sjdfgdjsgfjd\sgfju

A

hdjgcujdgvzd,hgfv

62
Q

Investigating the actvity of dehydrogenase in chloroplast:
What does NADP act as in photosystem I during the light-dependent reaction?
What happens to the NADP as a result?

A

⦾ An electron acceptor

⦾ It’s reduced

63
Q

Investigating the actvity of dehydrogenase in chloroplast:

What is the reaction catalysed by?

A

⦾ Dehydrogenase enzyme

64
Q

Investigating the actvity of dehydrogenase in chloroplast:

How can the activity of the enzyme be investigated?

A

⦾ Adding redox indicator dye to chloroplast extracts

65
Q

Investigating the actvity of dehydrogenase in chloroplast:

What does the REDOX indicator dye act as? (like NADP?)

A

⦾ Electron acceptor

⦾ Gets reduced by dehydrogenase in chloroplasts

66
Q

Investigating the actvity of dehydrogenase in chloroplast:

As the REDOX indicator dye gets reduced, what will you see?

A

⦾ Colour change

67
Q

Investigating the actvity of dehydrogenase in chloroplast:
Give an example of a dye?
What colour does it change to?

A

⦾ DCPIP

⦾ Blue to colourless (when reduced)

68
Q

Investigating the actvity of dehydrogenase in chloroplast:

How can you measure the rate of dehydrogenase activity?

A

⦾ Measure rate at which REDOX indicator dye (DCPIP) changes colour
⦾ Use colorimeter

69
Q

What is a colorimeter?

A

⦾ How much light solution absorbs when light source is directly shone through it
⦾ Coloured solution absorbs more light than colourless solution

70
Q

What is phosphorylation? (1)

A

⦾ Adding Pi to molecule (1)

71
Q

Under which process does phosphorylation occur? (1)

A

⦾ ADP + Pi via condensation reaction using energy (1)

72
Q

Where is energy stored in ATP? (1)

A

⦾ Energy stored as chemical energy in phosphate bond (1)

73
Q

Which enzyme catalyses the synthesis of ATP? (1)

A

⦾ ATP synthase (1)

74
Q

When energy is needed, ATP… (1)

A

⦾ …diffuses to part of cell energy’s needed (1)

75
Q

What happens when ATP reaches part of cell where its needed? (1)

A

⦾ Broken down into ADP + Pi (hydrolysis) (1)

76
Q

Which enzyme catalyses the breakdown of ATP? (1)

A

⦾ ATP hydrolase (1)

BIOLOGY A2 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions