short answer question list

Question 1

2 ways how photorespiration is detrimental to a plant?

Answer 1

1) lack of co2 fixation: diverts resources and energy away from efficient carbon fixation and carbohydrate production

2) wasteful energy consumption of ATP

Question 2

why is photorespiration a greater problem in warmer climates than in cooler climates?

Answer 2

• In warmer climates, there is increased water loss that may occur so the stomata will open far less to prevent water loss, this causes the lack of gas exchange and entry of CO2 which can lead to O2 being fixated to Rubisco instead and cause photorespiration.
• warmer climates, with water evaporation can also result in increased o2 production so if gas exchange is occurring in areas with higher amounts of o2, there will be a greater chance of photorespiration occurring there

Question 3

would a green plant grow better under a green light or a red light?

Answer 3

red light:

• chlorophyll absorbs red light and reflects green light, red light is effective for photosynthesis because it stimulates PSI and PSII in the chloroplasts, promoting the efficient conversion of light energy into chemical energy for the photosynthetic process.
• plants can still grow under green light, but the effects would be minimized

Question 4

What is driving the ETC in P1 and P2

Answer 4

light energy that causes the electron to get excited, and allows the electron to enter a series of reDox reactions

Question 5

does the presence or absence of light affect starch production?

Answer 5

During the day when there is sufficient light, photosynthesis converts light energy into chemical energy in the form of ATP and NADPH. These energy carriers are used in the Calvin cycle to fix carbon dioxide and produce sugars that can be converted and stored as starch.

Without light, NADPH and ATP cant be produced because there is no light energy to be converted to chemical energy

Question 6

Explain how CAM and C4 plants are more successful than C3 plants

Answer 6

CAM and C4:
- use PEP carboxylase instead of rubisco to reduce the effects of photorespiration
- adapt to intense environment conditions; high light intensity, high temperature
- developed mechanisms to minimize water loss, can be evolutionary even

Question 7

the green grass stain question

Answer 7

shows that chlorophyll eventually breaks down: important to recognize because chlorophyll can be used in nutrient recycling

Question 8

a botanist takes a sample of chloroplasts from a plant. the plant has been thriving under normal conditions in the greenhouse. upon examining the chloroplasts under the microscope, the botanist notices they contain a very high concentration of ATP but very little NADPH. what are some possible explanations for the high concentration of ATP?

Answer 8

1) issue in electron flow: An increased flow of electrons through the cyclic electron transport pathway, which generates ATP without producing NADPH, might result in the observed high concentration of ATP and low NADPH.

2) Imbalance in the Light-Dependent Reactions: The high concentration of ATP and low NADPH might suggest an imbalance in the light-dependent reactions of photosynthesis. This imbalance might occur due to factors such as an excess of light intensity or altered conditions affecting the electron transport chain (ETC). A higher ATP concentration might result from increased electron flow through the photosystems, leading to more ATP production compared to NADPH.

3) Disruption in the Calvin Cycle: An alteration or disruption in the Calvin cycle, the dark reactions of photosynthesis, could potentially result in an accumulation of ATP and a deficit of NADPH. If the Calvin cycle is unable to efficiently utilize ATP due to limited availability of NADPH, the excess ATP might accumulate within the chloroplasts.

Question 9

what conditions would maximize photosynthesis and minimize respiration?

Answer 9

• maintaining an adequate temperature, not too high (where respiration can occur), not too low either, where neither can occur properly

-stomata openings

• moderate light levels
• CO2 concentration; enough to prevent photorespiration

Question 10

why do the plants in hot areas suck, and are cool in the rainforests?

Answer 10

suck in the hot areas:

• WUE and reduced photorespiration
• reduces these photorespiration chances of occuring

cool in rainforests:

• more moderate temperature and nice moist climate
• C3 photosynthesis: less efficient but more common