Brainscape's Knowledge GenomeTM

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


See full index

A-Level Biology ONLY > EN: Photosynthesis > Flashcards

EN: Photosynthesis Flashcards

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

Where does photosynthesis take place?

A

Chloroplasts.

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

Chloroplasts

A

Flattened organelles surrounded by a double membrane.

Found in plant cells.

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

Thylakoids

A

Fluid-filled sacs stacked up in the chloroplast into structures called grana.

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

Grana

A

Stacks of thylakoids.

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

Lamellae

A

Thylakoid membranes that link together the grana.

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

What photosynthetic pigments do chloroplasts contain?

Where are they found?

A
  • Chlorophyll A
  • Chlorophyll B
  • Carotene

Found in the thylakoid membranes - attached to proteins.

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

Flattened organelles surrounded by a double membrane.

Found in plant cells.

A

Chloroplasts

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

Fluid-filled sacs stacked up in the chloroplast into structures called grana.

A

Thylakoids

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

Stacks of thylakoids.

A

Grana

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

Thylakoid membranes that link together the grana.

A

Lamellae

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

What is the use of photosynthetic pigments in chloroplasts?

A

They are coloured substances that absorb light energy needed for photosynthesis.

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

Photosystem

A

Protein and pigment that are attached in the chloroplast.

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

What are photosystems used by plants for?

How many are there?

What wavelength do they best absorb light at?

A

To capture light energy.

There are 2 : photosystem I (PSI) or photosystem II (PSII).

PSI = 700nm

PSII = 680nm

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

Stroma

A

Gel-like substance, contained in the inner membrane, surrounding the thylakoids.

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

Protein and pigment that are attached in the chloroplast.

A

Photosystem

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

Gel-like substance, contained in the inner membrane, surrounding the thylakoids.

A

Stroma

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

What does the stroma contain?

A

Enzymes, sugars and organic acids.

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

What happens to carbohydrates produced by photosynthesis?

A

Most is not used straight away and is stored as starch grains in the stroma.

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

What are the stages of photosynthesis?

A
  1. Light-dependent reaction
  2. Light-independent reaction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Briefly describe the light-dependent reaction stage of photosynthesis:

A
  1. Light energy is absorbed by chlorophyll in the photosystems.
  2. Light energy excites the electrons in the chlorophyll, leading to eventual releases from the molecule - chlorophyll has been photoionised.
  3. Some energy from the released electrons is used to add a phosphate group to ADP to form ATP, and some is used to reduce NADP to reduced NADP.
  4. ATP transfers energy and reduced NADP transfers hydrogen to the light-independent reaction.
  5. H2O is oxidised to O2.
21
Q

Where does the light-dependent stage of photosynthesis occur?

A

Thylakoid membranes of the chloroplasts.

22
Q

What is produced in the light-dependent stage of photosynthesis?

A

ATP and reduced NADP.

23
Q

In the light-dependent stage of photosynthesis, what does each product do?

A

ATP = transfers energy to light-independent reaction

Reduced NADP - transfers hydrogen to light-independent reation.

24
Q

What is the light-independent stage of photosynthesis also called?

A

The Calvin cycle

25
Q

Where does the light-independent stage occur?

A

In the stroma

26
Q

Briefly, what happens in the light-independent stage of photosynthesis?

A

ATP and reduced NADP from the light-dependent reaction supply the energy and hydrogen to make simple sugars from CO2

27
Q

How is ATP made in the light-dependent reaction?

A

Photophosphorlyation

28
Q

In the light-dependent reaction, the energy produced from the photoionisation of chlorophyll is used for what?

A
  1. Making ATP from ADP and inorganic phosphate - phosphorylation.
  2. Making reduced NADP from NADP.
  3. Splitting water into protons, electrons and oxygen - photolysis.
29
Q

What types of phosphorylation does the light-dependent stage include?

What is the difference?

A

Non-cyclic and cyclic.

Each has different products.

30
Q

What are photosystems linked by?

A

Electron carriers - proteins that transfer electrons.

31
Q

Electron transport chain

A

Chain of proteins through which excited electrons flow.

Formed from photosystems and electron carrier chains.

32
Q

Briefly describe what happens during the light-dependent stage of photosynthesis:

A
  • Light energy absorbed by chlorophyll in the photosystems.
  • Excites electrons - leads to their release from chlorophyll.
  • Energy released is used to add a phosphate group to ADP to ATP and also to reduce NADP to form reduced NADP.
  • H2O is oxidised to O2
33
Q

Draw a diagram to show how the light dependent reactions and the calvin cycle are linked:

A
34
Q

Chemiosmosis

A

Process of electrons flowing down the ETC and creating a proton gradient across the membrane to drive ATP synthesis.

35
Q

What photosystem does cyclic phosphorylation use?

A

PSI

36
Q

What does the Calvin Cycle make?

What does it make this from?

A

A molecule of triose phosphate.

Made from CO2 and ribulose bisphosphate.

37
Q

How many carbons does ribulose bisphosphate have?

A

5 carbons.

38
Q

What is triose phosphate used for?

A

To make glucose and other organic substances.

39
Q

Briefly describe the steps of the calvin cycle:

A
  1. Carbon dioxide is combined with ribulose bisphosphate to form two molecules of glycerate 3-phosphate.
  2. ATP and reduced NADP are required for the reduction of GP to triose phosphate.
  3. Ribulose bisphosphate is regenerated.
40
Q

What happens in the 1st stage of the Calvin Cycle?

A
  • CO2 enters leaf through stomata and diffuses to stroma.
  • Combined with RuBP - 5 carbons.
  • Catalysed by enzyme rubisco.
  • Gives an unstable 6-carbon compound called glycerate 3-phosphate (GP).
41
Q

What happens in the 2nd stage of the calvin cycle?

A
  • Hydrolysis of ATP (light-dependent) provides energy to turn GP into TP.
  • Also requires H+ ions from reduced NADP (LD).
  • Reduced NADP is recycled to NADP.
  • Some triose phosphate is converted to useful organic compounds - some continues in calvin cycle to regenerate RuBP.
42
Q

In the Calvin cycle, what does reduced NADP from the light dependent reactions do?

A

Reduces GP to TP.

43
Q

What happens in the 3rd stage of the calvin cycle?

A
  • Five out of 6 moleculed of TP aren’t used to make hexose sugars, but to regenerate RuBP.
  • Regenerating RuBP uses the rest of the ATP produced by the light-dependent reaction.
44
Q

The light-independent reaction/the calvin cycle, can also be known as what?

A

Carbon dioxide fixation because carbon from CO2 is ‘fixed’ into an organic molecule.

45
Q

Draw a diagram of the Calvin Cycle:

A
46
Q

What are TP and GP used to make after the calvin cycle?

Explain in detail.

A
  • Carbohydrates - hexose sugars made by joining two TP molecules.
  • Lipids - made using glycerol, which is synthesised from TP, and fatty acids, which are synthesised from GP.
  • Amino acids - some are made from GP.
47
Q

How many times does the Calvin cycle need to turn to make one hexose sugar?

A

6 times.

48
Q

Why does the calvin cycle need to turn 6 times to make one hexose sugar?

How much ATP and reduced NADP does this need?

A
  • 3 turns of the cycle produces 6 molecules of TP, as 2 molecules of TP are made for every CO2 molecule used.
  • 5/6 of these TP molecules are used to regenerate RuBP.
  • So, for 3 turns of the cycleonly 1 TP produced is used for a hexose sugar.

​

  • Hexose has 6 carbons, so two TP molecules are needed to form one.
  • Therefore, cycle has to turn 6 times to produce 2 x TP.
  • 18 ATP and 12 reduced NADP from light-dependent reaction are needed for this.*

A-Level Biology ONLY (45 decks)

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