PHOTOSYNTHESIS Y2 PT.3

Question 1

What is the LDR also known as

Answer 1

The Calvin cycle

Question 2

Where does the Calvin cycle take place

Answer 2

In the stroma of the chloroplasts

Question 3

What does the Calvin cycle make

Answer 3

A molecule called triode phosphate from CO2 and ribulose biphosphate ( a five carbon compound)

Question 4

What can triose phosphate be used to make

Answer 4

Glucose and other useful organic substances

Question 5

What does the Calvin cycle need to keep it going

Answer 5

H+ ions. And ATP

Question 6

The reactions in the Calvin cycle are all linked in a cycle which means the starting compound ____ is ________

Answer 6

Ribulose biphosphate

Regenerated

Question 7

What is carbon dioxide combined with ribulose resulting in

Answer 7

Two molecules of glycerate 3 phosphate

Question 8

What are all the steps to forming the two molecules of glycerate 3 phosphate

Answer 8

CO2 enters the leaf through the stomata and diffuses into the stroma of the chloroplast

Here, it’s combined with ribulose biphosphate a five carbon compound. This reaction is catalysed by the enzyme rubisco

This gives an unstable 6 carbon compound which quickly breaks down into two molecules of a 3 carbon compound called glycerate 3 phosphate

Question 9

what are ATP and reduced NADP required for

Answer 9

the reduction of GP to triose phosphate

Question 10

what is the hydrolysis of ATP from the LDR used for

Answer 10

it provides energy to turn the 3-carbon compound,GP, into a different 3- carbon compound called triose phosphate.

Question 11

what does the reaction of creating triose phosphate also require

Answer 11

H+ ions which come from reduced NADP (also from the LDR) reduced NADP is recycled to NADP

Question 12

what is some triose phosphate converted into after being formed from GP

Answer 12

some triose phosphate is then converted into useful organic converted into useful organic compounds (e.g. glucose) and some continues in the calvin cycle to regenerate RuBP

Question 13

what are five out of every six molecules of Triose Phosphate used for

Answer 13

not to make hexose sugars, but to regenerate ribulose bi phosphate

Question 14

what does regenerating RuBP use

Answer 14

the rest of the ATP produced by the LDR

Question 15

what is the Calvin cycle the starting point for

Answer 15

it is the starting point for making all the organic substances a plant needs

Question 16

what are triose phosphate and glycerate 3- phosphate (GP) molecules used to make

Answer 16

carbohydrates, lipids, and amino acids

Question 17

how do TP and GP make carbohydrates

Answer 17

hexose sugars e.g. glucose are made by joining two triose phosphate molecules together and larger carbohydrates (e.g. sucrose starch cellulose) are made by joining two hexose sugars together in different ways.

Question 18

how do TP and GP form lipids

Answer 18

these are made using glycerol, which is synthesised from triose phosphate, and fatty acids, which are synthesised form glycerate 3-phosphate

Question 19

how do TP and GP form amino acids

Answer 19

some amino acids are made from glycerate 3-phosphate

Question 20

what are all the parts of the Calvin cycle

Answer 20

1) Carbon dioxide is combined with ribulose biphosphate to form two molecules of glycerate 3-phosphate
2) ATP and reduced NADP are required for the reduction of GP to triose phosphate
3) ribulose bi phosphate is re generated