Photosynthesis

Which of the following can happen when a photosynthetic pigment pigment absorbs light?

exciton transfer, photooxidation, energy lost as heat, energy given off by fluorescence

The Z-scheme of photosynthesis produces a 3:2 ratio of ATP:NADPH. How does a C4 plant compensate for the greater ATP requirement created by the C4 pathway?

more cyclic photophosphorylation must occur

During the oxidation of water, where do the protons go?

thylakoid lumen

What part of the chloroplast is the site of energy-transducing reactions of photosynthesis?

thylakoid membrane

If carbon dioxide is used as a substrate, the major products of rubisco are _________; if oxygen is used as a substrate, the major products are ______.

2 molecules of 3-phosphoglycerate; 2-phosphoglycolate and 3-phosphoglycerate

Chlorophylls and carotenoids absorb most light between _________ nm and ________ nm, while reflecting most light between _______ nm.

400-500 and 600-700, reflect 500-600

The production of one molecule of glucose requires ________.

6CO2, 18 ATP, 12 NADPH

Which of the following shows the correct movement of electrons in the Z-scheme of photosynthesis?

H20, P680, plastoquinone, cytochrome b6f, platocyanin, P700, ferredoxin, NADP+

Complete the following reaction: P680 + light → ______ → ________.

P680* => P680+ and e-1

The active group of photosystem I is known as ________

P700

Which of the following best describes how a reaction center is excited?

any antenna of the light harvesting complex can transfer an electron to the reaction center by exciton transfer

Cytochrome b6f is most similar to mitochondrial _______ with the exception that electrons are passed to _______, not to cytochrome c.

complex III, plastocyanin

What were the first organisms that had the ability to oxidize water?

cyanobacteria

In the rubisco mechanism, what performs the nucleophilic attack on carbon dioxide?

enodialate intermediate

Why does rubisco make up about half of the protein content in a typical chloroplast?

it is a very inefficient enzyme, catalyzing only three reactions per second

Why is photosystem I unable to oxidize water?

it is not a strong enough oxidizing agent

What is an assembly of antenna pigments?

light harvesting complex

Regeneration of the rubisco substrate, ribulose-1, 5-bisphosphate involves which of the following sugars?

pentose phosphate, hexose phosphate, heptose phosphate, tetrose phosphate

Light dependent ATP production is called _______ and occurs in the ________ of chloroplasts.

photophosphorylation, thylakoid membrane

Which of the following occurs during the cyclic electron flow?

photosystem I absorbs light, not PS II

Electrons are transferred from P680 to ________, then to cytochrome b6f.

plastoquinone

The carbon fixing reactions occur in the _______.

stroma

The P680 of photosystem II is composed of ____________.

two chlorophylls