Photosynthesis

Question 1

Factors affecting Calvin cycle
-CO2 conc

Answer 1

When conc of CO2 is reduced then less is available to react with RuBP and therefore less GP and triose phosphate are formed and the levels of RuBP increase

Question 2

Factors affecting Calvin cycle
-Light intensity

Answer 2

when light is removed, the light dependent reactions can’t take place and consequently there is no ATP or NADPH available for the reduction of GP to trial phosphate
Therefore the conc of GP rises but the conc of trials phosphate and RuBP falls

Question 3

Factors affecting Calvin cycle
-Temperature

Answer 3

As the temperature increases the rate of reaction increases but the relative levels of intermediates are unchanged

However at higher temperatures oxygen competes with carbon dioxide for the rubisco enzyme and so less carbon dioxide is fixed. This results in photorespiration

The conc of all RuBP rises and the conc of GP and triose phosphate fall

At very high temperature rubisco enzyme may denature

Question 4

Limiting Factor
-CO2 conc

Answer 4

Use a propane burner to increase CO2 in the air

Question 5

Limiting Factor
-Light

Answer 5

Light passes through the glass, and fluorescent lighting can be used at nighttime

Question 6

Limiting Factor
-Temperature

Answer 6

Glasshouses will trap heat energy from sunlight which increases the temperature. Heaters can be used to increase temperature and cooling systems and air vents can be used to decrease the temperature.

Question 7

Autotrophs

Answer 7

•E.G. plants and algae
•Able to carry out photosynthesis and use simple inorganic molecules to synthesise complex organic molecules such as glucose.
•Energy is obtained from light plants and algae

Question 8

Heterotrophs

Answer 8

E.G. animals and fungi
•Organisms which obtain organic molecules by digesting and absorbing complex organic molecules
•The organic molecules are used for growth or respiration

Question 9

Thylakoids

Answer 9

•Site of LDR
•contain photosystems/photosynthetic pigments E.G.chlorophyll

Question 10

Granum

Answer 10

•stacks of thylakoids
•stacked to maximise likelihood of light striking photosynthetic pigments

Question 11

Stroma

Answer 11

•Site of LIR (calvin cycle)
•contains enzymes E.G. rubisco

Question 12

Starch grains

Answer 12

Store products are photosynthesis as starch

Question 13

70s ribosomes

Answer 13

Site of protein synthesis for the chloroplast

Question 14

circular DNA

Answer 14

carries genes coding for proteins/enzymes found in the chloroplast

Question 15

inner and outer of membrane

Answer 15

•Enclose stroma and separate contents from cytoplasm
•Control passage of substances in and out of the chloroplast

Question 16

Inter membrane space

Answer 16

Space between outer and inner membranes

Question 17

Lipid globules

Answer 17

•for chloroplast membrane information •for some chlorophyll formation

Question 18

photosynthetic pigments

Answer 18

•These are chemicals that absorb light energy (photons)
•Found in the thylakoid membranes of chloroplast
•Each pigment absorbs light energy of a particular range of wavelength of light energy

Question 19

Name photosynthetic pigments

Answer 19

Chlorophyll A- green-blue
Chlorophyll B- green
Carotene- orange
Xanthophyll- yellow

Question 20

accessory pigment

Answer 20

molecules (E.G. carotenoids) surround the primary pigments and absorb light energy and pass the energy from one to another and onto the primary pigment

Question 21

Primary pigments

Answer 21

reaction centres where electrons are excited to higher energy levels during the LDR
(usually chlorophyll A)