Chapter 8.3- Capturing sunlight into chemical forms

Question 1

What is a major energy entry point for light energy in photosynthesis?

Answer 1

Chlorophyll

Question 2

What is visible light?

Answer 2

The portion of electromagnetic spectrum we can see with our eyes and the waves included in photosynthesis.

Around 400 nm to 700 nm

Question 3

What are pigments? How do they work? What do they do?

Answer 3

• They absorb wavelengths of visible light
• They reflect the color of light of pigments they do not absorb

Question 4

What are the structural components of chlorophyll and how does it aid photosynthesis?

Answer 4

1. Light absorbing head with double donds and single bonds alternating
2. Hydrocarbon side chain

Question 5

What are photosystems? What are they made of?

Answer 5

• pigment protein complexes that contain the section of light absorption and that drives ETC

They contain:
- chlorophyll
- Accessory pigments

Question 6

Why are accessory pigments helpful?

Answer 6

• they help absorb light that chloropyll poorly absorbs

Question 7

Compare the absorption of light in chlorophyll that is isolated vs antenna chlorophyll

Answer 7

Isolated Chlorophyll: results in heat released when electron is in excited state and fluorense in ground state

Antenna Chlorophyll: results in just the transfer of energy/electron in neighboring chlorophyll

Question 8

What is the reaction center and what does it do with electrons?

Answer 8

The reaction center is where antenna chlorophyll transfers final electrons go. They turn the electrons into chemical energy. The formation of NADPH

Question 9

Do chlorophyll molecules operate on their own or in groups? ( explain through experiment)

Answer 9

Measurement 1: They measured the amount of oxygen was in the chlorella cell

Measurement 2: They measured the chlorella after exciting the electrons

Conclusion: There was a higher ratio of chlorophyll than oxygen. Meaning there is more than one chlorophyll needed to produce electrons

Question 10

What challenges do photosystems face by using water as an electron donor? How do they overcome it?

Answer 10

1. Hard to pull electroms from water
2. They divide into to photosystems. The first system electrons is pulled from water. The second system electrons are transferred from NAD+ to NADH

Question 11

Explain the Z scheme?

Answer 11

Energy decreases when electrons move between the two photosystems

Energy increases when electrons pass through the photosystem

Question 12

What is ferredoxin- NAP+?

Answer 12

it is a protein that helps cataylze NAPH formation by transferring two electrons of ferredoxin to NADP+

Question 13

How does chloroplast accumulate in the lumen?

Answer 13

1. The oxidization of water released protons into the lumen
2. cytochrome–b f complex and plastoquinone together act as a proton
   pump that functions much like proton pumping i

Question 14

Where is ATP produced in chloroplast?

Answer 14

movement of protons from the thylakoid lumen to the stroma

Question 15

Why is the Cyclic electron transport chain needed?

Answer 15

The Calvin cycle needs three ATP molecules but it doesnt produced enough ATP.

• electrons from photosystem I are
  redirected from ferredoxin back into the electron transport chain
• more proteins are transported from the stroma to the lumen