BIO 221 Herman Gingerich - Photosynthesis

What environment do C4 plants thrive in?

Warm and dry climates

What environment do C3 plants thrive in?

Cool and moist environments

Where does photosynthesis occur in CAM plants

Mesophyll cells

Pigment that bacteria use to absorb light

Bacteriophyll

Organisms that perform anoxygenic photosynthesis

Purple bacteria, green sulfur bacteria

Organisms that perform oxygenic photosynthesis

Plants, algae, cyanobacteria

What happens in phase 1 of the Calvin Cycle?

Carbon fixation

CO2 is attached to an organic molecule via rubisco

What happens in phase 2 of the Calvin Cycle?

Reduction and carbohydrate production

ATP used as source of energy

NADPH donates high-energy electrons

12 ATP—>12 ADP

12 NADPH —>12 NADP+ and 12 phosphates

What happens in phase 3 of the Calvin Cycle?

Regeneration of RuBP

3 G3P creates glucose and other sugars

Remaining 10 G3P regenerates RuBP via several enzymes

6 ATP—>6 ADP

Products of the Calvin Cycle:

G3P (Glyceraldehyde 3-phosphate) (builds glucose and other organic molecules)

ADP

NADP+

(ADP and NADP+ is used in light reactions)

What can 6 CO2 produce after the Calvin Cycle?

1 glucose, 18 ADP, 12 NADP+

What can 1 CO2 produce after the Calvin Cycle?

1/6 glucose, 3 ADP, 2 NADP+

What does noncyclic electron flow produce?

ATP, NADPH, and oxygen

What does cyclic flow produce?

ATP, PMF

Does the Calvin Cycle need products from the noncyclic electron flow?

No!

Which direction do electrons flow in noncyclic electron flow?

PSII to PSI

What happens to electrons after leaving PSII?

Transferred to cytochrome complex or ATP synthase

What happens to electrons after leaving PSI?

NADP+ becomes NADPH

How does NADP+ become NADPH in noncyclic electron flow?

NADP+ reductase

What promotes proton motive force in noncyclic electron transport?

Splitting (oxidation) of water

Transfer of high energy electrons from PSII to PSI

Formation of NADPH

What is one factor that promotes proton motive force in noncyclic electron transport?

Splitting (oxidation) of water

What is a second factor that promotes proton motive force in noncyclic electron transport?

Transfer of high energy electrons from PSII to PSI

What is a third factor that promotes proton motive force in noncyclic electron transport?

Formation of NADPH

What is photophosphorylation?

Sunlight being converted into ATP

How is ATP produced in noncyclic electron transport?

Photophosphorylation

Does cyclic electron flow produce reducing power

No!

What proteins are used in cyclic electron flow?

Ferredoxn and plastocyanin

What are chlorophyls composed of?

Porphyrin ring and phytol tail

How is energy and the rate of photosynthesis related?

Directly; More energy = High rate of photosynthesis

What are the two main types of pigments

Chlorophyll and cartenoids

What is one of the main types of pigments

Chlorphylls

What is one of the main types of pigments

Cartenoids

What does the thylakoid lumen contain?

Water

What doe photosystems II and I contain?

PIgments that absorb light

Where do light reactions occur?

Thylakoid membrane

What do light reactions produce?

ATP, NADPH, O2

Where does the Calvin cycle occur?

Stroma

How does the Calvin Cycle use CO2, ATP, and NADPH

To create carbohydrates

How does the energy of photons and wavelengths relate?

Decrease of photon energy = Lower wavelengths

Increase of photon energy = Higher wavelengths

What colors are shorter and high in energy?

Violet, blue

What colors are longer and low in energy?

Orange, red

Why are pigments good at absorbing wavelengths of light?

They are electron dense

Where do light dependent reactions occur?

Chloroplasts

Where do light independent reactions occur?

Stroma