Brainscape's Knowledge GenomeTM

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


See full index

bio Mod 5 > Photosynthesis > Flashcards

Photosynthesis Flashcards

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

What is autotrophic nutrition?

A

Water and carbon dioxide used in organisms for energy

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

What is carbon fixation?

A
  • The process by which carbon dioxide is converted into sugars
  • helps to regulate the conc of carbon dioxide in the atmosphere
  • endothermic, requires energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a compensation point?

A
  • When photosynthesis and respiration proceed at the same rate so that there is no net gain or loss of carbohydrate
  • compensation period is the time taken to reach the compensation point and differs from plant to plant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the compensation point like for shade plants when they’re exposed to sun?

A

The compensation point is sooner than sun plants as sun plants require a higher light intensity to achieve their optimum rate of photosynthesis

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

What is the structure of chloroplasts?

A
  • Disc shaped
  • surrounded by a double membrane with an inter membrane space
  • fluid filled matrix: stroma
  • stacks of thylakoids membranes: grana
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the role/ structure of the grana?

A

-The site of the light dependant stage of photosynthesis
-Each granum is connected by intergranal lamellae
-Large surface area for:
•the distribution of photosystems that contain photosynthetic pigments that trap light energy
•electron carriers and ATP synthase enzymes needed to convert light energy into ATP

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

What is the role/contents of the stroma?

A
  • Contains enzymes needed to catalyse the reactions of the light-independent stage
  • contains loop of DNA that codes for proteins needed in photosynthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Explain the whereabouts and function of photosynthetic pigments

A
  • within photosystems, within thylakoids membranes: grana
  • Each pigment absorbs light of a particular wavelength and reflects other wavelengths of light
  • light captured is channeled down to the primary pigment reaction centre containing chlorophyll at the base of the photosystem
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the two types of chlorophyll?

A
  • Chlorophyll a: photosystem I and photosystem II, appear blue-green
  • Chlorophyll b, appears yellow-green
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

A)What is photolysis?

B)What is water necessary for in the light-dependant stage?

A

A) In PSII there is an enzyme which splits water into H+, electrons and O2

B)source of hydrogen ions which are used in phosphorylation, donates electrons to chlorophyll which are lost when light strikes, keeps plant turgid, source of oxygen

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

What wavelength does photosystem I absorb?

A

700 nm

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

What wavelength does photosystem II absorb?

A

680 nm

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

What is non-cyclic phosphorylation?

A

Part of the light dependant stage which involves PSI and PSII to produce ATP, oxygen and reduced NADP

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

What is cyclic phosphorylation?

A

Part of the light dependant stage which involves only PSI to produce ATP no photolysis

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

What is the pH like in the stroma?

A

Concentration of free protons in the stroma falls as they are pumped into the thylakoids spaces pH raises to around 8 which is optimum for the enzyme RuBisCO

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

What are the uses of triose phosphate(TP)?

A
  • some glucose is converted to sucrose, some to starch and some to cellulose
  • some TP is used to synthesise amino acids, fatty acids and glycerol
17
Q

What is the effect on the Calvin cycle when there’s little or no light?

A
  1. GP cannot be reduced to TP
  2. TP levels fall and GP accumulates
  3. This means RuBP cannot be regenerated
18
Q

What happens to the Calvin cycle when the concentration of carbon dioxide becomes too low?

A
  1. RuBP cannot accept it so accumulated
  2. GP cannot be made
  3. Therefore TP cannot be made
19
Q

How does temp affect the rate of photosynthesis?

A
  • Rate of Photosynthesis increases as temp increases
  • At 30•C oxygen competes with CO2 for RuBisCO’s active site resulting in less GP and therefore TP
  • At 45•C enzymes may be denatured reducing conc of GP, TP and RuBP
20
Q

What is water stress?

A
  1. The roots are unable to take up enough water to replace that lost in transpiration
  2. Cells loose water- plasmolysed
  3. Plant roots produce abscisic acid causing stomata to close reducing gaseous exchange
  4. Tissues become flaccid, leaves wilt
  5. Rate of photosynthesis reduces

bio Mod 5 (6 decks)

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