Brainscape's Knowledge GenomeTM

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


See full index

Biology- topic 5 energy transfers in and between organisms > Photosynthesis > Flashcards

Photosynthesis Flashcards

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

What is catabolism?

A

breakdown of a substance releasing energy - respiration

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

What is anabolism?

A

synthesis of substances requiring energy - photosynthesis

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

Describe the structure of a chloroplast

A

double membrane, contains stroma (liquid inside) thylakoids stacking to form grana

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

What joins grana together?

A

intergranal lamellae

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

What makes up a photosystem?

A

pigment and proteins

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

What are thylakoids?

A

disc shaped fluid filled sacs made of thylakoid membrane

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

What is the stroma?

A

contains enzymes and starch granules (and chloroplast DNA and ribosomes)

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

How do thylakoids assist in photosynthesis?

A

-contain photosynthetic pigments to absorb light energy
-large SA as discs stacked to increase light absorption
-contains ATP synthase required to make ATP

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

What are the two reactions?

A

light dependent
light independent

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

What does the LDR produce?

A

ATP
NADPH

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

What is NADP?

A

a coenzyme

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

Why is it essential to break the bonds between the coenzyme and the product after a reaction?

A

to avoid drop in coenzyme concentration

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

Where does the LDR take place?

A

thylakoid membrane

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

What is the difference between PSII and PSI?

A

absorb different wavelengths of light

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

What happens in the LDR?

A

-light energy absorbed by PSII, exciting the electrons causing them to leave the chlorophyll to a higher energy level (photoionisation)
-the excited electrons pass from one carrier to the next along the electron transport chain, losing energy as they travel
-this energy is used to drive a protein pump that actively transports protons from the stroma to the inside of the thylakoid
-the electrons that left PSII are replaced due to photolysis of water- splitting water into oxygen, protons, and electrons
-electrons in PSI are also excited by light and passed along a second electron transport chain, where they react with protons and NADP to form NADPH. the electrons are replaced by the electrons from PSII
-protons in the thylakoid lumen build up and generate a concentration gradient- this causes chemiosmosis, where the protons diffuse down the gradient into the stroma using ATP synthase, which in turn causes photophosphorylation (ADP + Pi –> ATP)

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

Why is oxygen produced as a byproduct of the LDR?

A

product of photolysis of water, can be used in respiration or diffuse out of the leaf as a waste gas

17
Q

What is the equation for photolysis of water?

A

2H2O –> 4H+ + 4e- + O2

18
Q

Where does the LIR take place?

A

stroma

19
Q

What can the LIR also be called?

A

Calvin Cycle

20
Q

What happens in the LIR?

A

-CO2 reacts with Ribulose Bisphosphate, catalysed with the enzyme rubisco, forming an unstable 6C compound which breaks down quickly to form 2 molecules of Glycerate-3-phosphate
-both molecules of GP are reduced to Triose Phosphate, requiring H+ provided by the reduction of NADPH, which requires energy from the hydrolysis of ATP
-5/6 carbons are used from the Triose Phosphate to reform Ribulose Bisphosphate, requiring ATP, but 1 carbon is used to form organic products like glucose/amino acids/glycerol

21
Q

How was the Calvin cycle discovered?

A

calvins lollipop experiments-
-made a suspension of algae, supplied with radioactive CO2
-use a flat sided flask to mimic the conditions of a leaf
-use a rapid action tap into hot alcohol/ethanol

-keep in a dark room, then switch light on for 5 second intervals, extract some algae, repeat every set time frame and analyse each sample

22
Q

Why use hot ethanol?

A

to freeze metabolic reactions/kill algal cells

23
Q

What indicator should you use to determine photosynthesis rate?

A

hydrogencarbonate-
red at normal CO2 levels (CO2 is acidic)
purple = decreased CO2 INCREASED PHOTOSYNTHESIS
yellow = increased CO2 DECREASED PHOTOSYNTHESIS

24
Q

What are the limiting factors of photosynthesis?

A

-temp ]–tend to come together
-light intensity ]
-CO2 concentration

25
Q

What is the ideal level of CO2?

A

0.04%

26
Q

What happens when CO2 is too high?

A

stomata close

Biology- topic 5 energy transfers in and between organisms (3 decks)

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