Ch. 14

Question 1

On what large complex is ATP synthesized and H+ ions flow back down their electrochemical gradient?

Answer 1

ATP synthase

Question 2

How does ATP synthase work?

Answer 2

It creates a hydrophilic pathway that allows H+ to flow down its electrochemical gradient, this drives the coupling of Pi to ADP.

Question 3

What is the source of energy to excite electrons in the chlorophyll molecule?

Answer 3

photons of light

Question 4

What ion is coordinated in the chlorophyll porphyorin ring structure?

Answer 4

Magnesium

Question 5

How does the chlorophyll molecule stay associated with the thylakoid membrane?

Answer 5

A long hydrophobic tail anchors it.

Question 6

How are the chloroplast membranes different than the mitochondrial membranes

Answer 6

There is a third membrane (thylakoid membrane)

Question 7

Why are the photosystems called p680 And p700?

Answer 7

The max wavelength of light that they can absorb.

Question 8

Was there oxygen on the early earth atmosphere?

Answer 8

no

Question 9

Where do we believe the first simple life forms evolved? Did they have oxygen or light? did they live under extreme pressure?

Answer 9

Near hydrothermal vents on the ocean.
no.
no.
yes.

Question 10

In the electron transport chain in photosynthesis, where is the ATP and NADPH synthesized?

Answer 10

Stroma

Question 11

Does cyclic photophosphorylation produce ATP?

Answer 11

yes

Question 12

Is the Calvin cycle catabolic or anabolic

Answer 12

anabolic

Question 13

does the Calvin cycle require a large amount of energy input

Answer 13

yes

Question 14

Why do you get less ATP from FADH2?

Answer 14

Because FADH2 is added one step further down the ETC

Question 15

Where does photosynthesis take place in plant cells

Answer 15

The chloroplasts of plant cells, more specifically within the thylakoid membranes.

Question 16

How does the antenna complex work and what part of chlorophyll molecule is being excited?

Answer 16

It consists of hundreds of chlorophyll molecules that absorb photons of light leading to the excitation of electrons that eventually pass this excitation via resonance transfer around until they reach the special pair of chlorophyll molecules that donate excited electrons to an electron transport chain of carrier molecules such as plastoquinone and plastocyanin

Question 17

What are the mobile electron carriers in photosynthesis?

Answer 17

Plastoquinone (Q), plastocyanin (pC), and ferredoxin

Question 18

How many electrons are needed to make 1 NADPH molecule?

Answer 18

4 electrons removed from 2 water molecules, (requires 4 photons light) O2 is released.

Question 19

What are the final end products of photosynthesis?

Answer 19

NADPH, ATP, O2

Question 20

What are all these metal ions doing in these complexes?

Answer 20

Metal atoms from part of the resonance energy transfer system of the antenna complex that will ultimately impart this excitation to the special pair of chlorophyll molecules in the reaction center:

Question 21

What is the Calvin cycle or light-independent reaction and where does it occur?

Answer 21

it converts CO2 into sugars and it occurs in the stroma of the chloroplasts

Question 22

Does the Calvin cycle occur at night or during the day?

Answer 22

Can occur in the day or night—these are the light-independent reactions of photosynthesis

Question 23

Is it activated by light?

Answer 23

Indirectly, yes. It is indirectly activated by the presence of CO2 and ATP/NADPH

Question 24

How does the CO2 get into the leaf cell and ultimately into the chloroplast?

Answer 24

Diffuses through the stomata of plant cells; its a small non polar molecule

Question 25

Is the Calvin cycle endergonic (requires an input of energy)?

Answer 25

yes

Question 26

What high energy molecules are used in the Calvin cycle to drive the synthesis of glyceraldehyde-3-phosphate?

Answer 26

ATP and NADPH

Question 27

If your ATP levels were low would you engage in more cyclic photophosphorylation?

Answer 27

yes, when NADPH accumulates, the cell tends to favor this cyclic scheme.