5.2 Photosynthesis (Overview)*

Question 1

What is Carbon Dioxide reduced to?

Answer 1

Carbon Dioxide is reduced as hydrogen and electrons from water are added to it creating a carbohydrate.

Question 2

What is the process of splitting up water?

Answer 2

Photosynthesis uses energy from sunlight to split water

Process is called photolysis of water: involvement of energy from light in the reaction

Question 3

What can be glucose be converted to?

Answer 3

Glucose is converted into a variety of chemical substances needed by the plant
	• Starch
	• Cellulose
	• Fats
	• Amino Acids
	• Proteins
	• Nucleic acids

Question 4

What are the extra elements and where are they taken up?

Answer 4

Extra elements: nitrogen + phosphorous (taken up by the roots from soil)

Question 5

Why is Photosynthesis important?

Answer 5

1. Organic molecules are passed on through food webs
   
   2. Animals cannot make all the organic compounds
   3. Plants release oxygen gas into the atmosphere which organisms need for aerobic respiration

Question 6

What are the two stages of Photosynthesis?

Answer 6

1. Light-Dependent Reactions: Energy from light + hydrogen from photolysis of water: produce reduced NADP, ATP + waste produce oxygen.
   
   2. Light-Independent Reactions: Use reduced NADP + ATP from the light-dependent reactions to reduce carbon dioxide to carbohydrates.