2. photosynthesis:energy from sunlight (calvin cycle) Flashcards
(40 cards)
what is the second stage of photosynthesis?
the Calvin cycle
what does the Calvin cycle do?
fixes CO2 into glucose
in order for CO2 to be useful ______ has to be bonded to another ______
carbon
______ is reduced to form _____
CO2 - glucose
the Calvin cycle happens in te ____
stroma
engird in ATP and NADPH in the stroma is used to ____ CO2’s _____ into a ______ from
fix , useable
what are the 3 main stages of the Calvin cycle?
carbon fixation, carbon reduction, regeneration
**** stage 1: carbon fixation what happens in this process? DRAW THIS
RuBP(5C molecule) bind with CO2 by an enzyme called rubisco… to make a highly unstable 6C molecules that is quickly broke down to .. 2 molecules of 3-PGA
***stage 2: reduction what happens in this stage? DRAW THIS
start with a 3-PGA (product of stage 1) consume a pÍ from ATP that will make P-C-C-C-P but this will then be reduced by NADPH to form a new 3C molecule called G3P
*** stage 3: regeneration explain.. DRAW THIS
some of the G3P will make glucose and the leftovers will regenerate the OG molecule RuBP so it can pick up another CO2 and enter the Calvin cycle again BUT REGENERATING RuBP CONSUMES AN ATP
FINALLY #___ ____ and #___ _____ used for every Calvin cycle
2 ATP and 1 NADPH
the products of the Calvin cycle are ____ for all ____ on earth
crucial for all LIFE
fun fact… all the carbon containing atoms/molecules in your body was once…
CO2 from the atmosphere
_______ is the enzyme in the Calvin cycle
rubisco
rubisco usually uses _____ as a substrate to fix carbon BUTTTTTT rubisco sometimes make the mistake to use _____ instead of _____
CO2, oxygen, CO2
what happens when rubisco and O2 combine?
photorespiration… loss of carbons , it is a mistake that hurts the plant
formula of photorespiration
RuBP+ O2 = phosphoglycolate + 3PG
what does phosphoglycolate do in photorespiration?
it will inhibit reactions within the Calvin cycle so it NEEDS TO GET RID OF
when photorespiration happens in the plant, the plant looses?
25%/ Quarter of glucose that can be made
when high concentration of O2 rather than CO2 can occur on ____,____ days (the ______ (plant nostrils) will ____ to prevent ____ loss.
hot, dry , stomata will close to prevent water loss
Plants do or do not differ in how they fix CO2
THEY DO DIFFER
** describe C3 plants
use rubisco as the 1st enzyme, 1st product being 3PG because stomata is closed and O2 doesn’t come in or out SO on hot dry days photorespiration occurs
C4 plant use a different?
1st enzyme
C4 plants #1 product is _________ which has #___ ________
oxaloacete , 4 carbons