photosynthesis year 2

Question 1

what are chloroplasts`

Answer 1

they are flattened organelles surrounded by a double membrane. They are found in plant cells.

Question 2

what are thylakoids

Answer 2

they are fluid filled sacs that are stacked up in the chloroplast into structures called grana. The grana are linked together by bits of thylakoid membrane called lamellae

Question 3

what are photosynthetic pigments

Answer 3

coloured substances that absorb the light energy needed fro photosynthesis. The pigments are found in the thylakoid membranes. Theyre attached to proteins. The protein and pigment is called a photosystem

Question 4

what are examples of photosynthetic pigments

Answer 4

chlorophyll a, chlorophyll b, and carotene

Question 5

how many photosystems are used by plants to capture light energy

Answer 5

2

Question 6

at what wavelegnths do photosystem 1 and 2 absorb light best

Answer 6

700nm

and 680nm

Question 7

what is the stroma

Answer 7

a gel like substance contained within the inner membrane of the chloroplast surrounding the thylakoids.

Question 8

when carbohydrates are produced by photosynthesis and not used straight away how are they stored

Answer 8

they are stred as starch grains in the stroma

Question 9

what are the two stages that make up photosynthesis

Answer 9

1) the light dependant reaction and 2) the light independant reaction

Question 10

what type of energy does the LDR need

Answer 10

light energy

Question 11

where does the LDR take place

Answer 11

within the thylakoid membranes of the podcast

Question 12

within the LDR’s how is light energy absorbed

Answer 12

absorbed by chlorophyll in the photosystems,

Question 13

how are electrons released from the molecule

Answer 13

the light energy excites the electrons in the chlorophyll, leading to their release from the molecule

the chlorophyll has now been photoionised

Question 14

how is the energy from the released electrons used

Answer 14

some of the released energy is used to add a phosphate group to ADP to from ATP, and some is used to reduced NADP to form reduced NADP.

Question 15

what does ATP transfer

Answer 15

energy

Question 16

what does NADP transfer

Answer 16

hydrogen to the LDR

Question 17

during the LDR what happens to to h20

Answer 17

it is oxidised to O2

Question 18

what is the LIR also known as

Answer 18

the calvin cycle and it doesnt use light energy directly (though relies on the product of the LDR)

Question 19

where does the LIR take place

Answer 19

the stroma

Question 20

from the LIR what do ATP and NADP supply

Answer 20

the energy and hydrogen to make simple sugars from CO2

Question 21

within the LDR what is ATP made by

Answer 21

photophosphorylation

Question 22

what is photophosphorylation

Answer 22

when you make ATP from ADP and inorganic phosphate

Question 23

in the LDR the energy resulting from the photoionisation of chlorophyll is used fro three things:

Answer 23

photophosphorylation

making reduced NADP from NADP

splitting water into protons,electrons and oxygen, this is called photolysis.