Brainscape's Knowledge GenomeTM

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


See full index

A level Biology > Topic 5.1 - Photosynthesis > Flashcards

Topic 5.1 - Photosynthesis Flashcards

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

What is ATP?

A

Adenosine Triphosphate. It is the source of energy for use at the cellular level.

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

Can ATP be stored? Why?

A

No, ATP cannot be stored as it is unstable.

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

Where do animals get their nitrate ions from?

A

From plants that contain nitrates, or from eating other animals that have eaten plants.

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

Where do plants get their nitrate ions from?

A

Soil.

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

What does ATP break down into?

A

ADP + Pi

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

When ATP is broken down, energy is released. What is the four processes that use this energy? Give an example of each process.

A
  1. Chemical - Synthesis.
  2. Osmotic - Active Transport.
  3. Mechanical - Muscle Contraction.
  4. Electrical - Motor neuron nerve cells.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give 5 reasons why ATP is useful.

A
  1. It is a single-step reaction (therefore is an immediate source of energy.)
  2. The energy released is large enough for most processes and has minimal waste.
  3. The activation energy is low, so the bonds are easier to break.
  4. It can be reformed.
  5. It cannot be transported out of the cell.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What kind of reaction converts ATP to ADP + Pi? What is used?

A

A hydrolysis reaction using the enzyme ATP hydrolase and a molecule of water.

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

What is released from the hydrolysis reaction?

A

Energy is available for cellular work.

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

What kind of reaction converts ADP + Pi to ATP? What is used?

A

A condensation reaction uses energy from sunlight or food and releases a molecule of water. The enzyme ATP synthase is used.

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

Describe how an ATP molecule is formed from its component molecules. (4 marks)

A

ADP (consisting of adenine, a ribose sugar and 2 phosphate ions) joins with a phosphate ion in a condensation reaction. This forms ATP. In this reaction, an enzyme called ATP synthase is used, and a molecule of water is released.

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

What is the LDR?

A

The Light-Dependent Reaction.

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

What is the first stage in the LDR?

A

Photoionisation.

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

What happens in Photoionisation?

A

Light energy (photons) hits the chlorophyll molecule of photosystem II. This excited the electrons in the chlorophyll, causing them to leave the chlorophyll molecule.

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

What happens to the chlorophyll in photoionisation?

A

It is oxidised.

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

The chlorophyll loses electrons, how are they replaced?

A

Chlorophyll gains electrons from photolysis (has been reduced.)

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

What is oxidation?

A

Loss of electrons and hydrogen ions, gain of oxygen.

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

What is reduction?

A

Loss of oxygen, gain of electrons and hydrogen ions.

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

Where do the electrons that have been emitted by the chlorophyll molecule go to?

A

Primary acceptors.

20
Q

Where do the electrons from the primary acceptor of Photosystem II go to?

A

They go through a series of reduction and oxidation reactions, passing through 3 electron carriers until it hits the chlorophyll molecule of photosystem I. (The electron carrier is first reduced as it gains an electron and then oxidised as it passes the electron.)

21
Q

What is the process of electrons passing through electron carriers called?

A

Photophosphorylation.

22
Q

What is the chain of electron carriers called?

A

The Electron Transport Chain.

23
Q

Once the electron hits the chlorophyll of photosystem I, what happens?

A

The chlorophyll is oxidised again as photoionisation occurs.

24
Q

Where do the electrons emitted by the primary acceptor of photosystem I go to?

A

NADP Reductase.

25
Q

What is NADP Reductase?

A

An enzyme that reduces NADP by giving it electrons (from photosystem I) and H+.

26
Q

Energy pumps H+ into the thylakoid lumen from the stroma. What happens to the H+?

A

The proton gradient is dissipated and leaves the interior of the thylakoid.

27
Q

How do the H+ ions leave the thylakoid?

A

Through a complex of a proton pure and ATP synthase.

28
Q

What happens during the proton pores?

A

As the protons pass the pores, energy is released. This energy helps in the synthesis of ATP.

29
Q

What is the name for actively pumping in H+?

A

Chemiosmosis.

30
Q

Crops use light energy to produce photosynthetic products. Describe how crop plants use light energy during the light-dependent reaction (5)

A
  1. Light energy (photons) hit the chlorophyll molecule in photosystem ll causing the electrons in the chlorophyll to become excited. Due to this, electrons are emitted from chlorophyll will transferred to the primary acceptor. This causes the chlorophyll to become oxidised and the primary acceptor reduced.
  2. The electrons then go through a series of redox reactions when passing, 3 electron carriers in the electron transport chain, where the electron carrier is first reduced (gains the electron) and then oxidised (loses it to the next) releasing energy.
  3. This energy is used to join ADP and Pi to form ATP. In photosystem I another photon hits the chlorophyll and photoionisation occurs again. Electrons from the electron carriers replace the lost electrons and the chlorophyll has been reduced.
  4. Photolysis is when water is split up to form electrons, hydroxide ions and hydrogen ions (the electrons go back into the chlorophyll to make up for the ones lost.) The process is known as photoionisation.
  5. The electrons then leave photosystem I and go to NADP reductase. NADP reductase takes these electrons and extra H+ ions and gives them to NADP, reducing it to form reduced NADP.
31
Q

What does the LIR stand for?

A

Light - independent reaction.

32
Q

What is another name for the LIR?

A

The Calvin cycle.

33
Q

Where does the Calvin cycle take place?

A

In the stroma of the chloroplast.

34
Q

What does the LIR use from the LDR?

A

It uses the products of the LDR, which is reduced NADP and ATP.

35
Q

What are the three main stages of the Calvin cycle?

A
  1. Fixation of Carbon.
  2. Reduction phase.
  3. Regeneration phase.
36
Q

Roughly, what happens in the fixation of Carbon?

A

An enzyme called rubisco adds a CO2 molecule to RuBP to form GP.

37
Q

Where does the CO2 come from?

A

The atmosphere.

38
Q

What is the full name of RuBP? What is it made up of?

A

Ribulose bisphosphate. 5 carbons, 2 phosphates.

39
Q

What does GP stand for? What is it made up of?

A

Glycerate -3phosphate. It has 3 Carbons, 1 phosphate. There are usually 2 of these molecules formed.

40
Q

Generally, what happens in the reduction phase?

A

GP is reduced to form 2 molecules of TP. It is reduced as it gains electrons and hydrogen ions from reduced NADP (a product of the LDR). It also gains energy to do this from the break down of ATP to ADP + Pi. The NADP has been oxidised and goes back to the LDR to be reduced. The ADP + Pi also go back so they can be synthesised by H+.

41
Q

What does TP stand for? What does it consist of?

A

Triose Phosphate. It has 2 molecules of 3 carbons and 1 phosphate.

42
Q

TP can join together to form what?

A

Glucose.

43
Q

What are some uses of glucose?

A
  1. Respiration.
  2. Starch.
  3. Lipids / Oils.
  4. Cellulose.
  5. When joined with Ammonium ions and Nitrate ions, it can form amino acids. These can create proteins which can make enzymes. Enzymes are useful (for example rubisco for the fixation of carbon.)
44
Q

Generally what happens in the regeneration phase?

A

TP loses a carbon (an enzyme takes it out). This forms RuP. Another molecule of ATP breaks down to form ADP and Pi. The Pi is what is added to RuP to form RuBP. RuBP is then ready to start the cycle again.

45
Q

What does RuP stand for? What is it made of?

A

Ribulose Phosphate. 5 carbons and 1 phosphate.

46
Q

What is the equation for Photolysis?

A

H20 -> 2e- + 2H+ + 1/2 O2

A level Biology (9 decks)

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