Ch 5 Photosynthesis

Question 1

Is Photosynthesis Endergonic or Exergonic? Why?

Answer 1

• Endergonic/Anabolic
• It uses light energy/not possible without sunlight
• Reactions are unfavorable

Question 2

What are photosynthesis inputs?

Answer 2

• Sunlight
• Water
• Carbon Dioxide

Question 3

What are photosynthesis outputs?

Answer 3

• Oxygen

- Glucose

Question 4

What is the mesophyll?

Answer 4

-Cells of the interior leaf that contains most of a plant’s chloroplasts

Question 5

What are Stomata’s?

Answer 5

-Pores that let in carbon dioxide and let out oxygen

Question 6

What is the Stroma?

Answer 6

-Fluid inside the chloroplast

Question 7

What do the veins of plants do?

Answer 7

-Deliver water and carry away sugar produced from photosynthesis

Question 8

Why do plants have a waxy covering?

Answer 8

-To prevent water loss

Question 9

What are the 2 stages of photosynthesis?

Answer 9

• Light-dependent reactions

- Light-independent cycle or the Calvin-Cycle

Question 10

Where does the light-dependent reaction occur?

Answer 10

Thylakoid membrane

Question 11

What does the light-dependent reaction produce?

Answer 11

It produces ATP and NADPH using light energy

Question 12

Where does the Calvin cycle take place?

Answer 12

The stroma

Question 13

What are photons?

Answer 13

Packets of light energy/Electromagnetic energy traveling in waves

Question 14

What are the 2 accessory pigments of photosynthesis and what do they do?

Answer 14

• Carotenoids
• Phycobilins
• They absorb photon energy and transfer it to chlorophylls

Question 15

Which chlorophyll is the most common? What is their purpose?

Answer 15

• Chlorophyll A

- Absorb light

Question 16

What happens when photons hit the thylakoids containing water?

Answer 16

• They get excited

- Increase in energy

Question 17

What are the 3 Stages of the Calvin cycle?

Answer 17

1. Carbon Fixation (Carbon paired with RuBP)
2. Reduction (ATP NADPH reduce Co2) then become ADP and NADP+ that go back to light cycle later
3. Regeneration of RuBP

Question 18

How many times does the Calvin cycle need to run to produce a 6 Carbon glucose molecule?

Answer 18

6 times

Question 19

In the second step, Reduction to make glucose, how many molecules of G3P make glucose?

Answer 19

2 molecules of G3P

Question 20

What do heterotroph’s depend on?

Answer 20

Autotrophs

Question 21

What happens when Rubisco mistakenly binds with Oxygen instead of Carbon Dioxide?

Answer 21

Photorespiration

Question 22

When is photorespiration more frequent?

Answer 22

Warmer weather

Question 23

What is the responsibility of Photosystem II? (PS680)

Answer 23

Oxidizes water- Oxygen is released, H+ is used to create a gradient.

Question 24

What is the responsibility of Photosystem I? (PS700)

Answer 24

• Transfers electrons from photosystem II to NADP+ reductase

- Involved in cyclic photophosphorylation (makes ATP using proton pump)

Question 25

Plants in the desert that close their Stomata at night to avoid water loss are called what?

Answer 25

CAM Plants (Crussulacean acids)

Question 26

How do CAM plants differ from C3 plants

Answer 26

Open stomata at night and when they are closed during the day, they convert CO2 for the Calvin cycle

Question 27

Describe C3 Plant

Answer 27

• Majority of plants
• Efficient use of ATP
• Photorespiration is an issue
• Uses light and Calvin cycle normally

Question 28

Describe C4 Plant

Answer 28

• Corn/sugar cane (Warm environment)
• Uses more ATP
• Less photorespiration
• Uses carbon uptake cycle and Calvin cycle

Question 29

Describe a CAM plant

Answer 29

• Cactus, Pineapple (Dry environment)
• Uses up more ATP
• Hard to Get enough CO2
• Less water loss ( Stomata are closed during the day)
• Uses carbon storage then Calvin cycle

Question 30

How many modes of photosynthesis are there?

Answer 30

3

• C3
• C4
• CAM