M14 PHOTOSYNTHESIS 2

Question 1

A process wherein chemical energy (from the light reactions – ATP and NADPH) and CO2 (from the atmosphere) are used to produce organic compounds (like glucose).

Answer 1

Calvin cycle

Question 2

3 Phases of Calvin Cycle

Answer 2

• Carbon Fixation
• Reduction
• Regeneration of RuBP

Question 2

This is the process of assimilating carbon from a non-organic compound (CO2) and incorporating it into an organic compound (carbohydrates).

Answer 2

Carbon Fixation

Question 3

In this phase the 3-PGA molecules created through carbon fixation are converted into molecules of simple sugar – glucose.

Answer 3

Reduction

Question 4

In ___________, 3 molecules of CO2 (from the atmosphere) are joined to 3 molecules of RuBP (a 5-carbon sugar) by Rubisco (an enzyme also known as RuBP carboxylase)

Answer 4

Carbon Fixation

Question 5

1. The 6 – carbon molecules are reduced by gaining electrons from NADPH.
2. Molecular rearranging with the use of ATP. The three 6-carbon molecules will split in half, forming six 3-carbon molecules.
3. One of these “extra” 3-carbon G3P/PGAL molecules will exit the cycle and be used to form ½ a glucose molecule.
4. Once the Calvin Cycle “turns” twice (well, actually 6 times), those 2 molecules of G3P (a 3-carbon carbohydrate) will combine to form 1 molecule of glucose (a 6-carbon carbohydrate molecule) OR another organic compound.

Answer 5

Reduction

Question 6

The remaining 5 G3P molecules (3-carbons each!) get rearranged (using ATP) to form 3 RuBP molecules (5-carbons each).

Answer 6

Regeneration of RuBP