Brainscape's Knowledge GenomeTM

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


See full index

Y13 A2 Biology > Photosynthesis > Flashcards

Photosynthesis Flashcards

1
Q

What is the equation for photosynthesis?

A

6CO₂ + 6H₂O + light energy —> C₆H₁₂O₆ + 6O₂

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

What is photosynthesis an example of?

A

A metabolic pathway

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

What is a metabolic pathway?

A

The process occurs in a series of small reactions controlled by enzymes

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 the structure of a chloroplast?

A

They are small, flat organelles surrounded by a double membrane.
Thylakoids are stacked up into structures called grana
Grana are linked together by bits of thylakoid membrane called lamellae

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

What do chloroplasts contain?

A

Photosynthetic pigments

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

What are some examples of photosynthetic pigments?

A

Chlorophyll a
Chlorophyll b
Carotene

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

Where are photosynthetic pigments found in the chloroplast?

A

Thylakoid membranes

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

What is the purpose of photosynthetic pigments?

A

To absorb the light energy needed for photosynthesis

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

What are photosynthetic pigments attached to? What is this combination called?

A

A protein

A photosystem

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

What are the two photosystems called and what wavelengths of light do they each absorb?

A

Photosystem ll comes first and absorbs light best at a wavelength of 680 nm
Photosystem l comes second and absorbs light best at a wavelength of 700nm

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

What is the stroma?

A

Gel-like substance which contains enzymes, sugars and organic acids

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

How are the carbohydrates produced by photosynthesis used?

A

They are stored as starch grains in the stroma

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

What is a redox reaction?

A

A reaction which involves both reduction and oxidation

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

What is OILRIG?

A

Oxidation is loss of electrons

Reduction is gain of electrons

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

What is a coenzyme and how do they work?

A

A co-enzyme is a molecule that aids the function of an enzyme as they work by transferring a chemical group from one molecule to another

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

Which co-enzyme is used in photosynthesis?

A

NADP

18
Q

What are the two stages of photosynthesis?

A

Light dependent

Light independent

19
Q

Where does the light-dependent reaction take place? Why?

A

The thylakoid membranes

This is where the photosynthetic pigments are

20
Q

What is the first stage of non-cyclic photophosphorylation?

A

Photoionisation

21
Q

Describe what happens during photoionisation.

A

The light energy is absorbed by the chlorophyll in the photosystems, causing an electron to become excited and be released from the chlorophyll molecule and the high energy electrons move down the electron transport chain to PSl

22
Q

What is the second stage during non-cyclic photophosphorylation?

A

Photolysis

23
Q

Describe what happens during photolysis.

A

The light energy splits up a water molecule at PSll into protons (H+ ions), electrons and oxygen

24
Q

What is the purpose of photolysis?

A

To replenish the lost electrons at PSll

25
Q

What is the equation for photolysis?

A

H₂O —> 2H⁺ + 2e⁻ + 1/2O₂

26
Q

What is the third stage of non-cyclic photophosphorylation?

A

The excited electrons lose energy as they move along the electron transport chain. This energy is used to actively transport H+ ions across into the thylakoid. This creates a proton gradient across the thylakoid membrane.

27
Q

What role does ATP synthase play in non-cyclic photophosphorylation?

A

Protons move down their concentration gradient into the stroma through ATP synthase. This energy from the movement drives the synthesis of ATP from ADP and an inorganic phosphate

28
Q

What is the final stage in non-cyclic phosphorylation?

A

The electrons are transferred to NADP with an H+ ion to form reduced NADP

29
Q

What is the chemiosmotic theory?

A

The process of electrons flowing down the electron transport chain and creating a proton gradient across the membrane to drive ATP synthesis

30
Q

What is cyclic photophosphorylation?

A

It only uses PSl

The electrons aren’t transferred to NADP but instead passed back to PSl via electron carriers

31
Q

What does cyclic photophosphorylation produce?

A

Doesn’t produce reduced NADP or oxygen

Small amounts of ATP

32
Q

Where does the Calvin cycle take place?

A

In the stroma of the chloroplast

33
Q

What enzyme is involved in the Calvin cycle?

A

Rubisco

34
Q

What is the first stage of the Calvin cycle?

A

CO2 enters the leaf through the stomata
Combines with 5 carbon ribulose biphosphate (RuBP)
Catalysed by rubisco

35
Q

What is the second stage of the Calvin cycle?

A

Forms an unstable 6 carbon compound which quickly breaks down into 2 glycerate-3-phosphate molecules, a 3 carbon compound

36
Q

What is the third stage of the Calvin cycle?

A

The hydrolysis of 2 ATP molecules provides energy to reduce the 3-carbon compound. It is reduced again when 2 molecules of reduced NADP are oxidised. This forms 2 molecules of triose phosphate, a 3 carbon molecule

37
Q

How are useful substances formed from the Calvin cycle?

A

One carbon atom is from TP for every cycle of the Calvin cycle

38
Q

What is the fourth stage of the Calvin cycle?

A

5 out of every 6 molecules of TP produced go on to regenerate 5 carbon molecule RuBP. This also uses ATP, breaking it down to ADP and an inorganic phosphate

39
Q

How many times does the Calvin cycle have to repeat in order to formulate a glucose molecule?

A

6 times

40
Q

What useful substances are formed from the Calvin cycle?

A

Carbohydrates
Lipids
Amino acids

41
Q

What is the purpose of ATP in the light-independent reaction?

A

To provide energy for the conversion of glycerate-3-phosphate into triose phopshate

42
Q

What is the purpose of NADPH in the light-independent reaction?

A

To reduce glycerate-3-phosphate to triose phosphate

Y13 A2 Biology (45 decks)

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