What is photosynthesis?
What are autotrophs?
"Self-feeding". (produces own food)
What can the carbon that's fixed and incorporated into sugars during photosynthesis be used for?
To build other types of organic molecules needed by cells.
What are heterotrophs?
"Different-feeding". (Can't convert carbon dioxide to organic compounds themselves.)
What is the equation for photosynthesis?
6CO2+6H2O --> C6H12O6+6O2 (carbon dioxide+water to glucose+oxygen)
What can photosynthesis be driven by?
A series of oxidation-reduction reactions.
What does the Calvin cycles convert ATP and NADPH to?
ATP to ADP and Pi, and NADPH to NADP+. (These can be reused as substrates in the light reactions.)
What absorbs light energy and converts it to chemical energy (through ATP and NADPH)?
Chlorophylls.
What are thylakoids?
Disc-like structures that are arranged in piles that resemble stacks of pancakes.
In the light-dependent reactions, what happens to the electrons?
Electrons are removed from water and excited (boosted to a high energy level by absorption of light energy).
What do glucose molecules provide for organisms? (two crucial resources)
Energy and fixed (organic) carbon.
What happens to the electrons that travel down the ETC?
Energy is released, and the energy is used to pump protons from stroma into the thylakoid interior, creating a gradient across the membrane. (The energy of the gradient is used to make ATP).
What is the carbon in organic molecules also called?
Fixed Carbon.
What happens to glucose molecules in a process driven by light energy?
Glucose molecules are constructed from water and carbon dioxide, and oxygen is released as a byproduct.
What are thylakoids also known as?
Grana.
Where does the Calvin cycle take place and require?
It takes place in the stroma and does not directly require light, but uses ATP and NADPH from the light-dependent reactions to fix carbon dioxide and produce three-carbon sugars, which combine to form glucose.
Photosynthesis
Light energy converted to chemical energy in the form of sugars.
What are the two main stages of photosynthesis?
Light-dependent reactions and the Calvin cycle.
How does photosynthesis affect the Earth's atmosphere?
Most photosynthetic organisms make oxygen gas as a byproduct, and the advent of photosynthesis 3 billion years ago changed life on Earth.
Are photosynthesis and cellular respiration the same when it comes to redox processes?
No.
Where are ATP and NADPH produced?
On the stroma side of the thylakoid membrane, there they can be used by the Calvin cycle.
What happens in a redox reaction?
One or more electrons are transferred from one molecule to another. The molecule that loses electrons becomes *oxidized*, while the molecule that gains electrons becomes *reduced*.
What are stomata (singular, stoma)?
Small pores found on the surface of leaves in most plants.
What happens in photosynthesis?
Solar energy is harvested and converted to chemical energy of glucose using water and carbon dioxide. Oxygen is released as a byproduct.
What are grana (singular, granum)?
Stacks of thylakoids.
What is also known as the light-independent reactions?
The Calvin cycle.
What is the steady increase in oxygen concentration in the Earth's atmosphere though to have influenced?
The evolution of aerobic life forms.
What is the stroma?
The fluid-filled space around the grana.
What is the thylakoid space?
The space inside the thylakoid discs.
How do glucose serve as fuel for cells?
Their chemical energy can be harvested through processes like cellular respiration, generating ATP for the cell's immediate energy needs.
What do stomata do?
They allow carbon dioxide to diffuse into the mesophyll layer and oxygen to diffuse out.
What happens to 'excited electrons'?
They are passed energetically "downhill" through a series of molecules embedded in the thylakoid membrane, known as the ETC (electron transport chain).
What role do photosynthetic organisms play?
They introduce chemical energy and fixed carbon into ecosystems by using light to synthesize sugars.
What do photosynthetic organisms remove from the atmosphere and do with this?
They remove large quantities of carbon dioxide from the atmosphere and use the carbon atoms to build organic molecules.
Where do light-dependent reactions take place and what do they require?
They take place in the thylakoid membrane and require a continuous supply of light energy.
What are chloroplasts and where are they located?
Tiny organelles specialized to carry out the reactions of photosynthesis. Located in each mesophyll cell.
What is carbon fixation?
When carbon from CO2 (inorganic carbon) is incorporated into organic molecules.
Do photosynthetic organisms produce their own food?
Yes.