chapter 10 Flashcards
In what ways is aerobic cellular respiration tied to photosynthesis?
Photosynthesis removes carbon dioxide from the atmosphere, and cellular respiration puts it back. Photosynthesis releases oxygen into the atmosphere, and cellular respiration uses that oxygen to release energy from food.
Autotrophs
sustain themselves without eating anything derived from other organisms, Producers of the biosphere, producing organic molecules from CO2 and other inorganic molecules, almost all plants are photoautotrophs, using the energy of sunlight to make organic molecules.
Heterotrophs
obtain their organic material from other organisms, Consumers of the biosphere, almost all heterotrophs, including humans, depend on photoautotrophs for food and O2
How does the chemical reaction of photosynthesis compare with the chemical reaction of aerobic cellular respiration? Do both processes occur in plants?
Photosynthesis reverses the direction of electron flow compared to respiration. Yes, both occur in plants.
What is the function of photosynthesis?
Photosynthesis converts light energy to the chemical energy of food
What is the function of the light reaction in photosynthesis?
The light reactions (in the thylakoids): Split H2O, Release O2, Reduce NADP+ to NADPH, Generate ATP from ADP by photophosphorylation
What is the function of the Calvin cycle (light independent reaction)?
The Calvin cycle (in the stroma) forms sugar from CO2, using ATP and NADPH
What is a pigment?
A substance that absorbs visible light; Different pigments absorb different wavelengths; Wavelengths that are not absorbed are reflected or transmitted
What is the function of chlorophyll pigments in photosynthetic organisms?
To absorb light energy for the light reaction
On what membrane do all photosynthetic organisms execute the light reactions?
Thylakoid membrane
What is the function of NADP+?
To pick up electrons and hydrogen to carry them to the Calvin Cycle.
What is the role of the thylakoid space and the stroma in the light reactions?
The thylakoid space holds the hydrogen ions for chemiosmosis and the stroma is the site of the Calvin Cycle
Linear electron flow
the primary pathway, involves both photosystems and produces ATP and NADPH using light energy; Releases oxygen
Cyclic electron flow
uses only photosystem I and produces ATP but not NADPH; No oxygen is released
Where does the Calvin Cycle occur?
Stroma of the chloroplast
