BIO 111: FOUNDATIONS OF BIOLOGY

LECTURE: CELLS III: "Photosynthesis"

Assumed Knowledge:

nothing new - yay!

Study Questions for Chapter 10:

• Briefly outline the two-step process of photosynthesis, including the inputs and products.
• In cyclic phosphorylation, the energy in sunlight is used to add P to ADP, making ATP. Explain how this is done, including the the action of a photosystem and electron transport chain.
• In order to make glucose from CO2, the CO2 must be reduced/"hydrogenated". What molecule is the reducing agent?
• Draw the diagram for the light reaction for sulphur photosynthesis.
• What organisms still use this reaction? Where do they live and why do they only live there?
• What was the major adaptive benefit for organisms that evolved PSII?
• Draw the diagram for the light reaction for oxygenic photosynthesis.
• Why is oxygen gas produced from photosynthesis?
• What types of organisms perform oyxgenic photosynthesis?
• Describe the Calvin Cycle, showing how the 30 carbons in 6 RuBP molecules are recycled and how 6 molecules of CO2 are used to form a glucose molecule. Be sure to include the products of the light reaction.
• How can dry conditions limit CO2 availability inside leaves? What happens as a consequence?
• Describe the modifications expressed by C4 plants, and explain why these adaptations improve performance in hot, dry conditions.
• Describe the modifications of CAM plants, and explain why these changes improve performance in hot, dry conditions.
• When did oxygen begin to accumulate in the Earth's atmosphere? What produced it? What fossil evidence corroborates this?
• What came first, oxygenic photosynthesis or aerobic respiration?