Photosynthesis Affectors

Question 1

What are 3 things that affect photosynthesis

Answer 1

Light intensity, temperature, co2 concentration

Question 2

What happens with more light?

Answer 2

Higher rate of photosynthesis

Question 3

What happens with higher temp?

Answer 3

Rate of photosynthesis raises until reaches 27° then decreases until 40° where completely denatures

Question 4

What happens with high co2 concentration?

Answer 4

Increases until reaches plateau

Question 5

What is photorespiration

Answer 5

Plant uses sun to produce co2 instead of o2

Question 6

Problem if photorespiration

Answer 6

Less sugar and starch are produced and plants have a difficult time surviving

Question 7

Where does photorespiration happen?

Answer 7

Calvin cycle

Question 8

What is the worlds most abundant enzyme?

Answer 8

RuBP

Question 9

RuBP is to plants as what is to humans?

Answer 9

PDC

Question 10

How did photorespiration start?

Answer 10

Co2 levels used to be much higher but as plants photosynthesized atmosphere filled with oxygen.
Oxygen now competes with co2 for RuBisCo bonding sites

Question 11

What happens if o2 enters RuBisCO instead of CO2?

Answer 11

Then there isn’t enough carbon to make PGA and sugars are made much slower

Question 12

What happens as temperature raises with photorespiration

Answer 12

More o2 finds it’s way into RuBisCO

Question 13

Main plants photorespiration

Answer 13

C3

Question 14

Solution for c3

Answer 14

Evolved and produced new mechanism called c4

Question 15

What changed in c4?

Answer 15

Palisade mesophyll cells surround bundle sheath cells

Question 16

Important enzyme helping with photorespiration

Answer 16

PEP carboxylaze.

Question 17

Photorespiration fighters

Answer 17

C4 and CAM

Question 18

Where does CAM exist?

Answer 18

Succulents such as cacti or dessert plants

Question 19

How do CAM plants resist photorespiration

Answer 19

Same 2 carbon fixing steps as c4 but not separated between mesophyll and bundle sheath instead the carbon dioxide fixing enzymes are in sane cells.

Question 20

How do CAM PLANTS WORK

Answer 20

Stomata open at night
Co2 diffuses into leaf and mesophyll cellsand foxes by c4 photosynthesis and changed into malic acid and stored in vacuoles until next day
When sun rises stomata closes and malic acid is transported out of vaculoe to cytoplasm
Then broken down and all co2 will enter chloroplast to be continued with closed stomata