Chapter 10: Photosynthesis

Question 1

An autotroph is:

Answer 1

Organism that produces its own food

Question 2

A heterotroph is:

Answer 2

An organism that does not produce its own food

Question 3

A photon is:

Answer 3

A particle of light

Question 4

Fluorescence is:

Answer 4

Light being released from an electron moving from a higher energy level to a lower energy level

Question 5

Where do light-dependent reactions begin in eukaryotes?

Answer 5

Antenna Complex

This is where light enters plant cells

Question 6

Where does ATP Synthesis take place in plant cells?

Answer 6

ATP is synthesized in the chloroplast stroma (“cytoplasm” inside of a chloroplast)

Question 7

Where does ATP synthesis take place in animal cells?

Answer 7

ATP is synthesized in the Cristae of mitochondria

Question 8

List the 3 phases of the calvin cycle

Answer 8

1. Fixation Phase
2. Reduction Phase
3. Regeneration Phase

Question 9

Detail the fixation phase of the calvin cycle

Answer 9

CO₂ reacts with RuBP

Fixes carbon and produces two molecules of phosphorylated 3-carbon organic acid (3PGA)

Question 10

Detail the Reduction phase of the calvin cycle

Answer 10

3PGA is phosphorylated to ATP, accepts electrons from NADPH, and is reduced

This produces glyceraldehyde-3-phosphate (G3P)

Question 11

Detail the regeneration phase of the calvin cycle

Answer 11

G3P keeps the cycle going for third phase of cycle: uses ATP to regenerate RuBP

Question 12

T or F: Photosystem II is the first complex in photosynthesis

Answer 12

True. Photosystem II is called photosystem II because it was discovered by scientists second, but it is actually the first complex in the process of photosynthesis

Question 13

Photosynthesis occours in the ______

Answer 13

Chloroplasts of plant cells

Question 14

Plants are not the only organisms that use photosynthesis. Name two other organism types that also use photosynthesis

Answer 14

Algae and cyanobacteria

Question 15

The photosynthetic electron transport chain is made up of these 4 primary protein complexes

Answer 15

Photosystem II, Cytochrome B6-F, Photosystem I, and ATP synthase

Question 16

The photosynthetic ETC is embedded in the _____

Answer 16

Thylakoid membrane of chloroplasts

Question 17

Photosystems I and II harvest energy from packets of light called photons using ______ ________

Answer 17

Antenna compelxes

Question 18

Antenna complexes are composed of _______

Answer 18

Chlorophyll molecules

Question 19

Give the overall reaction for photosynthesis

Answer 19

6 CO₂ + 6 H₂O + Solar Energy (Photons) = C₆H₁₂O₆ (glucose) + 6 O₂

Question 20

What does Oxygenic mean?

Answer 20

Production of oxygen via chemical reaction. EX: Photosynthesis turns CO₂ into O₂

Question 21

What does Anoxygenic mean

Answer 21

Photosynthesis that does not produce oxygen as a byproduct. EX: Bacterial photosynthesis in cyanobacteria

Question 22

Why are leaves green (reference the EM spectrum)

Answer 22

When light hits chlorophyll pigment, it will fluoresce with light that has a wavelength that humans see as the color green ( ~ 550 nanometers)

Question 23

What are the primary electron donors in photosynthesis

Answer 23

NADPH, H₂O

Question 24

What are the primary electron acceptors in photosynthesis?

Answer 24

NADP⁺

Question 25

How does ATP synthase produce ATP in the light-dependent reactions of photosynthesis?

Answer 25

A proton gradient is created by the photosynthetic electron transport chain, which drives ATP synthase which will turn an ADP and a Pi into ATP

Question 26

How does photorespiration affect the number of photons required to produce one glucose molecule?

Answer 26

A plant cell can use O₂ instead of CO₂ in the calvin cycle if necessary, however this is much less efficient and will waste a lot of NADPH as a consequence

Question 27

Explain the role of the stomata

Answer 27

Stomata can open and close to regulate the diffusion of molecules such as CO₂ and O₂ from in and out of the plant’s internal tissues

EX: Cacti stomata will close during the day to prevent water loss due to the extreme heat of their desert environments, but will open at night to allow photosynthesis to occur.

Question 28

Compare and contrast C₃, C₄ and CAM plants

Answer 28

CAM plants are the survivalists, with the least efficient energy production but the best water conservation. EX: cacti

C₄ plants are an in-between class between CAM and C₃ plants. Semi-efficient energy production and semi-effective water conservation. EX: wheat, corn

C₃ plants have the worst water conservation but the most efficient energy production. They require a consistently favorable environment and consistent water intake to survive. EX: your grandma’s azaleas.