Ch 5 Photosynthesis Flashcards
Is Photosynthesis Endergonic or Exergonic? Why?
- Endergonic/Anabolic
- It uses light energy/not possible without sunlight
- Reactions are unfavorable
What are photosynthesis inputs?
- Sunlight
- Water
- Carbon Dioxide
What are photosynthesis outputs?
- Oxygen
- Glucose
What is the mesophyll?
-Cells of the interior leaf that contains most of a plant’s chloroplasts
What are Stomata’s?
-Pores that let in carbon dioxide and let out oxygen
What is the Stroma?
-Fluid inside the chloroplast
What do the veins of plants do?
-Deliver water and carry away sugar produced from photosynthesis
Why do plants have a waxy covering?
-To prevent water loss
What are the 2 stages of photosynthesis?
- Light-dependent reactions
- Light-independent cycle or the Calvin-Cycle
Where does the light-dependent reaction occur?
Thylakoid membrane
What does the light-dependent reaction produce?
It produces ATP and NADPH using light energy
Where does the Calvin cycle take place?
The stroma
What are photons?
Packets of light energy/Electromagnetic energy traveling in waves
What are the 2 accessory pigments of photosynthesis and what do they do?
- Carotenoids
- Phycobilins
- They absorb photon energy and transfer it to chlorophylls
Which chlorophyll is the most common? What is their purpose?
- Chlorophyll A
- Absorb light
What happens when photons hit the thylakoids containing water?
- They get excited
- Increase in energy
What are the 3 Stages of the Calvin cycle?
- Carbon Fixation (Carbon paired with RuBP)
- Reduction (ATP NADPH reduce Co2) then become ADP and NADP+ that go back to light cycle later
- Regeneration of RuBP
How many times does the Calvin cycle need to run to produce a 6 Carbon glucose molecule?
6 times
In the second step, Reduction to make glucose, how many molecules of G3P make glucose?
2 molecules of G3P
What do heterotroph’s depend on?
Autotrophs
What happens when Rubisco mistakenly binds with Oxygen instead of Carbon Dioxide?
Photorespiration
When is photorespiration more frequent?
Warmer weather
What is the responsibility of Photosystem II? (PS680)
Oxidizes water- Oxygen is released, H+ is used to create a gradient.
What is the responsibility of Photosystem I? (PS700)
- Transfers electrons from photosystem II to NADP+ reductase
- Involved in cyclic photophosphorylation (makes ATP using proton pump)
Plants in the desert that close their Stomata at night to avoid water loss are called what?
CAM Plants (Crussulacean acids)
How do CAM plants differ from C3 plants
Open stomata at night and when they are closed during the day, they convert CO2 for the Calvin cycle
Describe C3 Plant
- Majority of plants
- Efficient use of ATP
- Photorespiration is an issue
- Uses light and Calvin cycle normally
Describe C4 Plant
- Corn/sugar cane (Warm environment)
- Uses more ATP
- Less photorespiration
- Uses carbon uptake cycle and Calvin cycle
Describe a CAM plant
- Cactus, Pineapple (Dry environment)
- Uses up more ATP
- Hard to Get enough CO2
- Less water loss ( Stomata are closed during the day)
- Uses carbon storage then Calvin cycle
How many modes of photosynthesis are there?
3
- C3
- C4
- CAM
