20 terms

BIOL 1201 (EXAM 3): Photosynthesis

Which of these equations best summarizes photosynthesis?
A. C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy
B. C6H12O6 + 6 O2 → 6 CO2 + 12 H2O
C. 6 CO2 + 6 H2O → C6H12O6 + 6 O2
D. 6 CO2 + 6 O2 → C6H12O6 + 6 H2O
E. H2O → 2 H+ + 1/2 O2 + 2e-
C. 6 CO2 + 6 H2O → C6H12O6 + 6 O2
Where does the Calcin cycle occur?
It occurs in the Stroma
The light reactions of photosynthesis use _____ and produce _____.
water ... NADPH
Which term describes ATP production resulting from the capture of light energy by chlorophyll?

**The excitation of chlorophyll by light energy initiates a chain of events that leads to ATP production.
True or false? The chemiosmotic hypothesis states that the synthesis of ATP generates a proton gradient that leads to electron flow through an electron transport chain.

**The chemiosmotic hypothesis states that the flow of electrons through an electron transport chain generates a proton gradient that leads to the synthesis of ATP
According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis?
Proton gradient

**A proton gradient across chloroplast and mitochondrial membranes drives ATP synthesis by the enzyme ATP synthase
Which of the following particles can pass through the ATP synthase channel?
True or false? The region of ATP synthase that catalyzes the production of ATP from ADP and inorganic phosphate spans the chloroplast membrane.

**The region of ATP synthase that catalyzes ATP production protrudes out of, but does not span, the chloroplast membrane; the region that spans the membrane is an ion channel through which protons can pass.
Chloroplast membrane vesicles are equilibrated in a simple solution of pH 5. The solution is then adjusted to pH 8. What conclusions can be drawn from these experimental conditions?
ATP will not be produced because there is no ADP and inorganic phosphate in the solution.
Which process produces oxygen?
Cellular Respiration or Photosynthesis?
Which set of reactions uses H2O and produces O2?
Light-independent reactions or light dependent reactions
light dependent reactions
What is the importance of the light-independent reactions in terms of carbon flow in the biosphere?
The light-independent reactions turn CO2, a gas, into usable carbon in the form of sugars.

**CO2 is unusable until plants have "fixed" this carbon into sugar.
True or false? The light-dependent reactions of photosynthesis use water and produce oxygen.

**The water molecules are split to replenish electrons in photosystem II, leaving behind protons, which are used to generate a proton gradient for the formation of ATP, and oxygen, which is released as a by-product.
Which of the following molecules is the primary product of photosystem I?

B. Oxygen
D. Carbon Dioxide
What is the biological significance of the light-independent reactions of photosynthesis?
They convert carbon dioxide to sugar.
Describe the relationship between the light-dependent and light-independent reactions of photosynthesis?
The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions.
Which of the following reactions ensures that the Calvin cycle can make a continuous supply of glucose?
A. Carbon fixation
B. Production of 3-phosphoglycerate
C. Production of G3P
D. Regeneration of RuBP
D. Regeneration of RuBP
Select the correct molecule that is the main product of the Calvin cycle.

B. Glucose
A. G3P
What is the basic role of CO2 in photosynthesis?

A. CO2 is fixed or incorporated into organic
B. CO2 is a source of electrons in the formation of
organic molecules.
C. CO2 is taken in by plants as a form of inverse
respiration, in which carbon dioxide is
"breathed in" and oxygen is "breathed out."
A. CO2 is fixed or incorporated into organic
Describe the basic function of the light reactions of photosynthesis.
The basic function of the light reactions of photosynthesis is the conversion of solar energy to chemical energy.