Photosynthesis

Question 1

two different stages?

Answer 1

Light dependent and light independent/Calvin’s cycle

Question 2

Place that dependent reaction takes place?

Answer 2

Thylakoid membrane

Question 3

Place independent reaction takes place?

Answer 3

Stroma

Question 4

What is photlysis?

Answer 4

Splitting of water with light

Question 5

What is a heterophobic organism?

Answer 5

Obtain complex organisms by eating other organisms

Question 6

What is a autotrophic?

Answer 6

An organism that photosynthesize

Question 7

Equation for photosynthesis?

Answer 7

6CO2 + 6H2O –> C6H12O6 + 6O2

Question 8

What is a thylakoid?

Answer 8

Flattened sacs formed by the membrane where photosynthesis takes place

Question 9

A stack of thylakoids is called a?

Answer 9

Grana (singular = granum)

Question 10

Colors that chlorophyll absorbs?

Answer 10

Red and blue, reflects green making the leaves that color

Question 11

Chlorophyll A?

Answer 11

The primary pigment, at the bottom of the photosystem

Question 12

Photosystem I?

Answer 12

Happens second has a wavelength of 700nm

Question 13

Photosystem II?

Answer 13

Happens first, has a wavelength of 680nm

Question 14

Chlorophyll B?

Answer 14

Accessory pigments, get excited by the light and vibrate creating kinetic energy

Question 15

Adaptations of the waxy cuticle?

Answer 15

Transparent for light to pass through, prevents water loss to the plant

Question 16

Palisade adaptations?

Answer 16

Close together = shorter diffusion pathways, contains loads of chloroplasts to absorb more light, close to top of leaf, columnar to fit more near the top

Question 17

Explain how the light dependent stage happens?

Answer 17

PSII occurs with sunlight, fires electrons slowly losing energy to get to an electron transport chain, photolysis of water happens to replenish the lost electrons, and producing hydrogen for NADP and oxygen as a byproduct. The electron transport chain produces ATP and the electrons go to PSI here’s where the electrons can either go cyclic or non-cyclic, back to the ETC or provide energy to NADP to make NADPH for the independent stage

Question 18

Products of the light dependent stage?

Answer 18

ATP, NADPH and O2

Question 19

First stage of the Calvin cycle?

Answer 19

RuBP combines with CO2 and is catalyzed by Rubisco to make a 6C compound

Question 20

2nd stage of Calvin’s cycle?

Answer 20

The 6C compound breaks down and makes GP and in the process makes carbon dioxide fixated, GP is converted into TP using NADPH and ATP energy

Question 21

What happens with TP in the Calvin’s cycle?

Answer 21

TP can be converted into hexose sugars such as glucose or glycerol, fatty acids and lipids. Or it will get recycled into RuBP to restart the cycle again

Question 22

Three overall steps of the Calvin’s cycle?

Answer 22

Fixation of CO2, Reduction of GP to TP and Regeneration of RuBP from recycled TP

Question 23

What is photorespiration?

Answer 23

When oxygen inhibits the enzyme Rubisco, reducing production of GP. Phosphoglycerate is formed, needs to be removed as toxic to the plant.

Question 24

Percentage of products lost during photorespiration?

Answer 24

25%

Question 25

The affinity of Rubisco?

Answer 25

High affinity for carbon dioxide compared to oxygen

Question 26

Why is the most critical enzyme in photosynthesis inhibited by a common molecule such as oxygen?

Answer 26

When plants evolved to respire in the beginning of time there was no oxygen present in the atmosphere, only CO2 and nitrogen. As time passed more oxygen came into the atmosphere, plants haven’t evolved to counter the increase in oxygen

Question 26

3 types of limiting factors?

Answer 26

Temperature, light intensity and CO2 concentration

Question 27

What happens as light intensity increases?

Answer 27

ATP and NADP are produced at a quicker rate so photosynthesis all together is performed quicker.

Question 27

What happens if light intensity is decreased?

Answer 27

Light dependent reaction will slow down, less ATP and NADP. Increase in GP concentration as less is being converted into TP as less ATP and NADP. As there is less TP that means less being recycled into RuBP

Question 28

What happens if temperature is increased?

Answer 28

The enzyme such as NADP and Rubisco are affected. Temp increase = more kinetic energy and successful collisions = more enzyme activity. Enzymes eventually denature which will slow down the process of photosynthesis.