Test Your Knowledge!

Input and Architecture

1. Why are leaves green?
    
2. Red light has a longer wavelength than blue light. Which light has higher energy?
    
3. What molecule in a plant actually absorbs the light energy needed for photosynthesis?
    
4. What are the products of the light reactions?
    

Light

1. Once a pigment loses an electron, what is its charge?
    
2. What type of agent removes the electrons from a photosystem?
    
3. Which direction, from high to low concentration, or from low to high concentration, do protons move to generate ATP?
    
4. What is one of the most limiting steps of photosynthesis?
    
5. What does it mean when we say a protein is reduced?

Input and Architecture Answers

1. Answer: Leaves are green because they are not good at absorbing green light for photosynthesis, and green light is therefore reflected, making the leaves green.
    
2. Answer: Blue light has higher energy than red light.
    
3. Answer: Chlorophyll is the pigment in plants that absorbs light energy for photosynthesis.
    
4. Answer: O₂, ATP, and NADPH are produced.
    

Light Answers

1. Answer: A pigment is positively charged after losing an electron.
    
2. Answer: An oxidizing agent removes electrons from the system; oxidizing agents can also be called electron acceptors.
    
3. Answer: Protons move from high to low concentration to generate ATP.
    
4. Answer: Carbon fixation by RuBisCo.
    
5. Answer: It gained an electron.