Photosynthesis

Question 1

What type of organisms do photosynthesis?

Answer 1

Both eukaryotes and prokaryotes can; plants, algae, and some bacteria

Question 2

Basic principle of photosynthesis?

Answer 2

Photosynthesis captures light energy from the sun and converts it to chemical energy.

Question 3

What’s the basic equation of photosynthesis?

Answer 3

Energy (from sun) + water + carbon dioxide = carbohydrates and oxygen

Question 4

What’s the actual equation of photosynthesis?

Answer 4

6CO2 + 6H2O —> C6H12O6 + 6O2

Question 5

What’s being reduced and why?

Answer 5

6Co2 is reduced to C6H12O6 because it is gaining electrons (via hydrogen)

Question 6

What’s being oxidized and why?

Answer 6

6H20 is oxidized to 6O2 because the hydrogen is taken away

Question 7

What’s a stomata?

Answer 7

On the surface of a plant cell (a pore) that opens/closes to accept Co2 and send out O2

Question 8

What’s a stroma?

Answer 8

The liquid inside a chloroplast

Question 9

What’s a granum?

Answer 9

A stack of thylakoids

Question 10

Oxygen is very electronegative. Why does this pose a problem for photosynthesis?

Answer 10

It is very difficult to oxidize water because it loves electrons

Question 11

What are the reactants in the light reaction phase?

Answer 11

Light, H20, NADP+, ADP + Pi

Question 12

What are the products of the light reaction phase?

Answer 12

O2, ATP, NADPH

Question 13

What are the reactants of the calvin cycle?

Answer 13

CO2, ATP, NADPH

Question 14

What are the products of the calvin cycle?

Answer 14

CH2O and NADP+ and ADP, Pi

Question 15

What wavelengths have higher energy?

Answer 15

Short wavelengths

Question 16

What wavelengths have lower energy?

Answer 16

Longer wavelengths

Question 17

What colors have higher energy/shorter wavelengths?

Answer 17

purple, blue, green

Question 18

what colors have lower energy, longer wavelengths?

Answer 18

yellow, orange, red

Question 19

What captures sunlight and how?

Answer 19

Chlorophyll (green pigment)

Question 20

What are the three pigments?

Answer 20

Chlorophyll a (key light capturing pigment)
Chlorophyll b (an accessory pigment)
Carotenoids (a separate group of accessory pigments)

Question 21

What happens when light hits a pigment?

Answer 21

Electrons move from the ground to an excited state

Question 22

What happens in PSII

Answer 22

Photons hit the chlorophyll pigments and excite them; water is oxidized and supplies additional electrons; as the electrons are excited, they move to another carrier

Question 23

what happens in the cytochrome complex?

Answer 23

Is a proton pump and lets more protons into the lumen. The energy is lowered here to supply H+ in the lumen

Question 24

What happens in PSI?

Answer 24

Photon light hits the chlorophyll molecules again and re-excites them

Question 25

What happens in the NADP+ reductase?

Answer 25

NADP+ reductase is an electron carrier and enzyme that reduces NADP+ to NADPH

Question 26

What happens in the ATP synthase?

Answer 26

It diffuses H+ using a proton gradient and makes ATP by photophosphorlyation (ADP, Pi to ATP)

Question 27

Where does the calvin cycle take place?

Answer 27

In the stroma

Question 28

What's phase 1 of the calvin cycle?

Answer 28

Carbon Fixation

Question 29

What's phase 2 of the calvin cycle?

Answer 29

Reduction

Question 30

What's phase 3 of the calvin cycle?

Answer 30

Regeneration

Question 31

What happens during Carbon Fixation?

Answer 31

Rubisco enzyme causes 3 CO2 molecules to interact with 3 RUBP to produce 6 PGA

Question 32

What happens during reduction?

Answer 32

The 6 3PGA uses 6ATP and 6NADPH to generate 6 G3P molecules Require ATP because it can't happen spontaneously 1 G3P molecule exits cycle here

Question 33

What happens during regeneration?

Answer 33

uses the other 5 molecules of G3P to and 3 ATP molecules to make 3 RuBP

Question 34

At the end of the calvin cycle, what molecules have the energy that originally came from light?

Answer 34

ATP and NADPH

Question 35

What product of G3P transports energy to other parts of the plant?

Answer 35

Sucrose

Question 36

What product of G3P stays stored in a plant for later use as an energy source?

Answer 36

Starch

Question 37

What's chemiosmosis?

Answer 37

the diffusion of H+ from the thylakoid space back to the storm down the gradient - powers ATP synthase and produces ATP

Question 38

What cells are involved in C4 plants?

Answer 38

Mesophyll and bundle-sheath cells

Question 39

What do C-4 plants have to overcome?

Answer 39

low CO2 levels because the stomata is closed to keep water in during hot, humid days/climates

Question 40

NADP

Answer 40

an electron acceptor as NADPH that stores electrons produced during light reactions throughout the electron transport chain

Question 41

C3 plants?

Answer 41

uses the Calvin cycle for the initial steps that incorporate CO2 into organic material

Question 42

In photosynthesis, what is the fate of the oxygen atoms present in Co2?

Answer 42

they end up as molecular oxygen (released through stomata) and in sugar molecules

Question 43

What is the role of NADP+ in photosynthesis?

Answer 43

It forms NADPH to be used in the calvin cycle

Question 44

A photon of which of these colors would carry the most energy? green yellow blue orange red

Answer 44

blue, the shortest wavelengths carry the most energy

Question 45

Based on the work of Engelmann, a ploy of photosynthetic activity versus wavelength of light is referred to as: an effective spectrum an absorption spectrum an electromagnetic spectrum a visible light spectrum an action spectrum

Answer 45

An action spectrum - which plots the effectiveness of different wavelengths of light in driving photosynthesis

Question 46

What structure is formed by the reaction center, light-harvesting complexes, and primary electron acceptors that cluster, and is located in the thylakoid membrane? the fluorescence center the photosystem the electron transport chain NADP+ reductase ATP synthase

Answer 46

the photosystem

Question 47

Where do the electrons entering photosystem II come from? ATP the electron transport chain light water

Answer 47

Water - key is paying attention to which photosystem

Question 48

During photosynthesis in a eukaryotic cell, an electrochemical gradient is formed across the? chloroplast outer membrane thylakoid membrane chloroplast inner membrane stomata cristae

Answer 48

thylakoid membrane - protons are pumped from the storm to the thylakoid space; locations are separated by the thylakoid membrane

Question 49

Of the following, which occurs in the calvin cycle? a. light energy is converted to chemical energy b. ATP and NADPH are synthesized c. CO2 is reduced d. excited electrons are conveyed from chlorophyll to an electron acceptor e. photons are absorbed

Answer 49

CO2 is reduced

Question 50

Which of the following occurs during the Calvin cycle? a. Light energy is converted to chemical energy. b. ATP is oxidized and NADPH is reduced. c. ATP is reduced and NADPH is oxidized. d. ATP is hydrolyzed and NADPH is oxidized. e. Linear electron flow produces the materials required for the fixation of carbon from carbon dioxide.

Answer 50

ATP is hydrolyzed and NADPH is oxidized - hydrolysis of ATP releases energy to drive endergonic reactions of the calvin cycle