Photosynthesis

Question 1

Where does photosynthesis take place specifically?

Answer 1

In the Chloroplasts

Question 2

What is the role of photosnythetic pigments?

Answer 2

Absorb the light energy needed for photosynthesis

Question 3

Where are the photosynthetic pigments found?

Answer 3

In the thylakoid membrane

Question 4

What is the attachment between a protein and a pigment called?

Answer 4

Photosystem

Question 5

What does the stroma contain?

Answer 5

Enzymes, sugars and organic acids

Question 6

Where does the light dependent reaction take place?

Answer 6

Takes place in the thylakoid membrane

Question 7

What is photoionisaition?

Answer 7

Light energy excites the electrons in the chlorophyll giving them more energy which eventually causes them to be released from the chlorophyll molecule

Question 8

Where does the light independent reaction take place?

Answer 8

In the stroma

Question 9

In the light dependent reaction what is the energy used for from the photoionisaition of chlorophyll?

Answer 9

1-Phosphorylation - making ATP from ADP and an inorganic phosphate
2-Making reduced NADP from NADP
3-Splitting water into ions, electrons and oxygen. (Photolysis)

Question 10

What types of Phosphorylation are there?

Answer 10

Non cylcic and cyclic

Question 11

What does cylcic phosphorylation produce

Answer 11

Only produces small amounts of ATP

Question 12

Why is it called cyclic phosphorylation?

Answer 12

Because the electrons aren’t passed from the chlorophyll molecule aren’t passed onto NADP but are passed back to PSI via electron Carriers

Question 13

Which is the photosystem involved in cylcic phosphorylation?

Answer 13

PSI

Question 14

What are photosystems in the thylakoid membrane ) linked to?

Answer 14

By electron Carriers

Question 15

What do the electron Carriers and the photosystems form?

Answer 15

An electron transfer chain - a chain of proteins through which excited electrons flow

Question 16

Where do high energy electrons go after they have been released from the chlorophyll?

Answer 16

They move down the electron transfer chain to PSI

Question 17

What process replaces the electrons released from photosystem ii when light is initially absorbed?

Answer 17

Photolysis

Question 18

What is the reaction for photolysis?

Answer 18

H20&raquo_space;»»> 2H+ 1/2 02

Question 19

How is Reduced NADP formed?

Answer 19

Light energy absorbed by PSI again excites electrons to an even higher energy level. Electrons are transferred to NADP along with a proton (H+ ion) from the stroma to form reduced NADP

Question 20

Where does the waste product oxygen come from in the light dependent reaction?

Answer 20

The photolysis of water

Question 21

Give the reaction in the Kalvin cycle that forms 2 GP

Answer 21

RuBP + C02 &raquo_space;»» 2GP

Question 22

What enzyme catalyses the reaction of GP

Answer 22

Rubisco

Question 23

What kind of reaction is the formation of Triose phosphate and what does it require and why does it require these molecules?

Answer 23

Reduction Reaction

Requires: Reduced NADP (used to reduce GP) and ATP (additional energy in the reaction)

Question 24

What is Triose phosphate used for?

Answer 24

Most used to be converted into glucose for respiration
Some used regenerate more RuBP
Some used for useful organic substances such as sucrose for transport and cellulose for storage.

Question 25

Name 4 environmental factors that may affect the rate of photosynthesis

Answer 25

Light intensity Carbon dioxide concentration Temperature Availability of water in the soil

Question 26

How does the management in a greenhouse/glasshouse affect the limiting factors of photosynthesis?

Answer 26

Carbon dioxide - added to air by burning small amount of propane in a C02 generator Light- Light can enter through the glass , lamps also provide light at night time Temperature- Glasshouses trap heat energy from sunlight which warms the air Heaters and cooling systems can also be used to keep a constant optimum temperature and air circulation systems make sure the temperature is even throughout the glasshouse

Question 27

What is light needed for on photosynthesis and how does it affect the rate of photosynthesis?

Answer 27

Needed to provide light energy for the light dependent reactions, higher wavelength of light more energy provided, only certain wavelengths of light are used for photosynthesis

Question 28

What is usually the optimum temperature for photosynthesis?

Answer 28

Around 25 degrees

Question 29

If temperature falls below 10 degrees what happens?

Answer 29

Enzymes such at ATP synthase and Rubisco become inactive due to low kinetic energy

Question 30

What happens if temperature goes above 45 degrees?

Answer 30

Above 45 degrees enzymes start to denature and stomata close to avoid water loss causing photosynthesis to slow down and less C02 enters leaf

Question 31

What is C02 needed for photosynthesis and what would happen if the level of C02 goes above 0.4%

Answer 31

Needed for formation of GP which leads to formation of glucose Any higher stomata starts to close

Question 32

What would happen if there is too much water and soil becomes waterlogged?

Answer 32

Roots unable to respire aerobically so less ATP for active transport of minerals into the roots. Minerals include magnesium which is needed to make chlorophyll a

Question 33

Which pigment absorbs green light?

Answer 33

Carotenoid (reflects the light so plants appear green)

Question 34

What is the equation for photosynthesis?

Answer 34

6C02 + 6H20 >>>>>> 602 + C6H1206