PHOTOSYNTHESIS Y2 PT.3 Flashcards
What is the LDR also known as
The Calvin cycle
Where does the Calvin cycle take place
In the stroma of the chloroplasts
What does the Calvin cycle make
A molecule called triode phosphate from CO2 and ribulose biphosphate ( a five carbon compound)
What can triose phosphate be used to make
Glucose and other useful organic substances
What does the Calvin cycle need to keep it going
H+ ions. And ATP
The reactions in the Calvin cycle are all linked in a cycle which means the starting compound ____ is ________
Ribulose biphosphate
Regenerated
What is carbon dioxide combined with ribulose resulting in
Two molecules of glycerate 3 phosphate
What are all the steps to forming the two molecules of glycerate 3 phosphate
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
what are ATP and reduced NADP required for
the reduction of GP to triose phosphate
what is the hydrolysis of ATP from the LDR used for
it provides energy to turn the 3-carbon compound,GP, into a different 3- carbon compound called triose phosphate.
what does the reaction of creating triose phosphate also require
H+ ions which come from reduced NADP (also from the LDR) reduced NADP is recycled to NADP
what is some triose phosphate converted into after being formed from GP
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
what are five out of every six molecules of Triose Phosphate used for
not to make hexose sugars, but to regenerate ribulose bi phosphate
what does regenerating RuBP use
the rest of the ATP produced by the LDR
what is the Calvin cycle the starting point for
it is the starting point for making all the organic substances a plant needs
what are triose phosphate and glycerate 3- phosphate (GP) molecules used to make
carbohydrates, lipids, and amino acids
how do TP and GP make carbohydrates
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.
how do TP and GP form lipids
these are made using glycerol, which is synthesised from triose phosphate, and fatty acids, which are synthesised form glycerate 3-phosphate
how do TP and GP form amino acids
some amino acids are made from glycerate 3-phosphate
what are all the parts of the Calvin cycle
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
