Lecture 14 & 15 Study Guide

Question 1

Give the full equation for photosynthesis State and briefly describe the two main reactions of photosynthesis. Explain how the reactants and products enter and exit the plant.

Answer 1

light energy + 6CO2 + 12H2O -> C6H12O6 + 6O2 + 6H2O

1. light reactions: water is split to O2
2. Carbon fixation reactions- incorporates CO2 from air into organic molecules already present in chloroplast

Question 2

Define what a pigment is and state the name of the three main photosynthetic pigments and the wavelengths of light they absorb.

Answer 2

pigment: a molecule that absorbs photons in the visible spectrum

chlorophyll a: 430nm (blue) to 662nm (red)
carotenoid: 400 (violet) to 5550 (green)
chlorophyll b: 460nm to 647nm

Question 3

Where does the Calvin cycle occur?

Answer 3

stroma of chloroplast

Question 4

What is the role of ribulose bisphosphate and Rubisco?

Answer 4

Rubisco is an enzyme used in carbon fixation; RuBp is a 5 carbon molecule used in the calvin cycle

Question 5

Where does the energy to fix gaseous CO2 come from?

Answer 5

from the ATP produced in the light reactions

Question 6

State the three main processes of the Calvin cycle.

Answer 6

1. carbon fixation
2. reduction and sugar formation
3. regeneration of CO2 acceptor

Question 7

List three fates of triose phosphate (G3P).

Answer 7

converted to glucose
converted to starch
used to regenerate RuBp