1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Luba_88 [7]
3 years ago
13

Some Calvin Cycle enzymes contain disulfide bonds that must be reduced through a mechanism involving thioredoxin in order for th

e enzyme to be active in sunlight. What is the name of the key regulatory protein that inactivates these same Calvin Cycle enzymes by oxidation when the sun goes down? Choose the ONE best answer.
Thioredoxin requires sunlight for proper folding into its functional three dimensional structure, so in the absence of light, it is unfolded and cannot reduce these enzymes.
The protein is called ferredoxin-thioredoxin reductase.
There is no regulatory protein that oxidizes these Calvin cycle enzymes; oxidation is spontaneous Sunlight is a reducing energy and moonlight is an oxidizing energy, so when the moon comes out at night, the Calvin Cycle enzymes are oxidized spontaneously.
None of these answers are correct
Thioredoxin has multiple light-sensing properties and when the sun goes down it turns into a strong oxidant.
Biology
1 answer:
Ann [662]3 years ago
8 0

Answer:

There is no regulatory protein that oxidizes these Calvin cycle enzymes; oxidation is spontaneous.

Explanation:

Four enzymes of the Calvin cycle are regulated by sunlight. These enzymes are namely Ribulose 5-phosphate kinase, fructose 1,6-bisphosphatase, sedoheptulose 1,7-bisphosphatase, and glyceraldehyde 3-phosphate dehydrogenase.

The inactive form of these enzymes has disulfide bonds between two Cys residues. In the presence of sunlight, the reduced thioredoxin that obtains electrons from PS-I via ferredoxin reduces the disulfide bonds between the Cys residues of these enzymes.

The reduction of the bonds brings about the confirmation changes to make the enzyme active.

At nightfall, these bonds are spontaneously re-oxidized and there is no reduced thioredoxin available to reduce them again. The spontaneous oxidation of the disulfide bonds of these enzymes at nightfall makes them inactive again.

You might be interested in
The pie chart tracks the percentage of renewable energy that’s being used in a particular community near the ocean. What are two
Jlenok [28]

Pie chart would be the answer.

7 0
2 years ago
Read 2 more answers
how does the nervous system help the body maintain homeostasis? if it doesn't function correctly how does it affect the body?
Alchen [17]

Answer:

Homeostasis is maintained at many levels, not just the level of the whole body as it is ... Of course, body temperature doesn't just swing above its target value

6 0
2 years ago
The process of growing together sediment by chemical action is called
maxonik [38]

Answer:cementation

Explanation:

7 0
2 years ago
What type of joints make up the skull?
Yanka [14]

Answer:

The bones of the skull are highly irregular. Most of the bones of the skull are held together by firm, immovable fibrous joints called sutures or synarthroses. These joints allow the developing skull to grow both pre- and postnatally.

Explanation:

6 0
3 years ago
Read 2 more answers
_____ is an autoimmune disease in which the body's immune system destroys insulin producing cells
Maslowich
I think the answer is diabetes, specifically type 1.
6 0
3 years ago
Other questions:
  • Tom wants to incorporate more organic practices on his farm. He wants to enrich the nitrogen content of his soil through biologi
    8·2 answers
  • The narrowest taxon in the Linnaean system is the genus, order, or species
    11·1 answer
  • A substance when dissolved in water increases the H= ion concentration of the solution. Which type of solution is formed?
    14·1 answer
  • What is it called when your muscle contracts tightly and stays that way?
    11·1 answer
  • HIGH CHANCE OF GETTING BRAINLIEST !!!!!!Which clouds are fluffy and white in the sky? A. cumulus B. nimbus C. cumulonimbus D. ci
    5·2 answers
  • Which of the following organelles is part of the endomembrane system?
    12·1 answer
  • Bell and collaborators painstakingly documented a population of fossil sticklebacks from an ancient freshwater lake over a 20,00
    9·1 answer
  • List the products of the Krebs cycle. what happens to each of these products
    9·2 answers
  • Question 10 (1 point)
    10·2 answers
  • Why cant you keep your tongue still?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!