1. AP BIOLOGY Photosynthesis What happens next?

2. What happens to the electrons in chlorophyll a in Photosystem II when light energy strikes the chloroplast?
What happens to the oxygen atoms that are released when water is split during the light dependent reactions?
They are excited to higher energy levels and pass to the primary electron acceptor and into ETC
Join to make O2 and are released into
the atmosphere

3. Which molecules are produced in the light dependent reactions?
What happens to the hydrogen released when water is split during the light dependent reactions?
Which molecules are produced in the
light dependent reactions?
Accumulates in thylakoid space and eventually passes through ATP synthase into the stroma and ends up in NADPH
ATP, NADPH, O2

4. Which molecule donates electrons to replace the electrons in chlorophyll a that are excited by light and passed to ETC?
Electrons are replaced when WATER is split

5. What happens to the NADPH made during the light reactions?
Which molecule(s) are produced in the
light independent reactions?
Used in Calvin cycle to make sugar
G3P (glucose)

6. What happens to excited electrons
What happens to the ATP that is made during the light dependent reactions?
What happens to excited electrons
from Photosystem I during cyclic electron flow?
Used in Calvin cycle to make sugar
Pass back to the ETC (cytochromes) instead of onto NADP+

7. What happens to the H+ ions that build up
in the thylakoid space during the light
dependent reactions?
Pass down their concentration gradient through
ATP synthase and provide power to add Pi
onto ADP to make ATP

8. What happens to the 4 carbon sugar made in the mesophyll when CO2 is fixed in C4 plants?
It is shuttled into neighboring bundle sheath cells and used in the Calvin cycle

9. Which molecule is the final electron acceptor at the end of ETC in the light dependent reactions?
What happens to light energy collected by carotenoids during the light dependent reactions?
NADP+
Excited electrons are passed to chlorophyll a in the reaction center

10. Where do the carbon and oxygen atoms in CO2 used in the Calvin cycle end up?
What happens to the ADP produced when ATP is used in the Calvin cycle to make sugar?
Incorporated into carbohydrates
Recycled and recharged in light dependent reactions

11. What happens to the electrons at the end of the electron transport chain?
Received by NADP+ to make NADPH

12. Which 4 carbon sugar is formed when PEP carboxylase adds CO2 to PEP?
What happens to the NADP+ produced when NADPH is used in the Calvin cycle to make sugar?
OAA-oxaloacetic acid
Recycled and recharged in light dependent reactions

13. What happens as a result of H+ ions passing through ATP synthase?
H+ ions provide energy to add Pi onto ADP to make ATP

14. What happens to the G3P produced in the Calvin cycle?
Which pathway do C3 plants follow on hot days when they have to shut their stomates to prevent dehydration and CO2 is low and O2 is high?
What happens to the G3P produced in the Calvin cycle?
photorespiration
Can be used to make glucose, starch, cellulose,
or become building blocks to make other macromolecules

15. Tell which molecule each of the atoms that end up in glucose originally came from:
_______ ________ _________
CO2
CO2
H2O