General Photosynthesis
Light Reactions
Light Reactions
Calvin Cycle
Photosynthesis and Cell Respiration
100
Does photosynthesis happen in all cells?
No, animal cells and fungi do not photosynthesize. (Some protists and prokaryotes photosynthesize but not all.)
100
In the very first step, water is split to make what molecule as a product?
oxygen
100
What is the name of the pigment that is housed in the photosystems that gets excited by the energy from light?
chlorophyll
100
Where in the chloroplast does the Calvin cycle take place?
stroma
100
The oxygen needed for cell respiration comes from what reactant of photosynthesis?
water (NOT carbon dioxide)
200
What organelle is responsible for photosynthesis?
Chloroplast
200
Which photosystem is activated first? second?
Photosystem II is activated first, then Photosystem I is activated second.
200
How is ATP made during photosynthesis? A. substrate-level phosphorylation B. oxidative phosphorylation C. photophosphorylation D. inorganic phosphorylation
(C.) photophosphorylation
200
What reactant is needed to start the Calvin cycle? What enzyme catalyzes this reaction?
carbon dioxide, CO2 rubisco
200
The products of photosynthesis are the reactants of respiration, and vice versa. Because of this, we say these two processes are _____________. A. endergonic B. exergonic C. coupled D. uncoupled
(C.) coupled
300
What type of macromolecule is made during photosynthesis?
Carbohydrates (sugars)
300
Where in the chloroplast does the process of the light reactions take place?
thylakoids (Photosystems and ETCs are embedded in the thylakoid membrane, and the H+ gradient is built in the thylakoid space.)
300
True/false - Photosynthesis occurs the same way in plant cells and prokaryotic cells.
FALSE! Prokaryotic cells have no membrane-bound organelles, which means no chloroplasts. The few prokaryotes that can photosynthesize do NOT have chloroplasts to use for this process.
300
Besides CO2, what other molecules are needed to power the Calvin cycle?
NADPH and ATP
300
True/False - Both mitochondria and chloroplasts have their own DNA and divide independently of the cell.
True!
400
What are the overall reactants and products of photosynthesis?
Reactants: water, carbon dioxide, light energy Products: oxygen, sugar
400
In the light reactions, which molecule gets reduced?
NADP+ is reduced to NADPH
400
What is the purpose of the first electron transport chain? The second?
1st - makes ATP (by creating a H+ gradient) 2nd - makes NADPH (by reducing NADP+)
400
During the Calvin cycle, when NADPH is transformed back into NADP+, we say it is ___(oxidized or reduced)____. Why?
oxidized because it loses hydrogen and electrons
400
Which two organelles are described in the endosymbiont theory?
mitochondria and chloroplasts The endosymbiont/endosymbiosis theory states that mitochondria and chloroplasts started out as early prokaryotic cells that were engulfed by larger eukaryotic cells. Over time, they became organelles. This theory is supported by both organelles having their own DNA and being able to divide independently of the rest of the cell, in a process similar to binary fission.
500
Photosynthesis is about making food using energy from light. Describe how the materials for food move through an ecosystem versus how energy moves through an ecosystem.
Matter/nutrients cycle and energy flows
500
In what type of plants do the light reactions happen at night?
none! They are the light reactions because they require light in order to happen!
500
How do C3, C4, and CAM plants differ with regard to the light reactions?
They don't. They differ with regard to the Calvin cycle.
500
On hot days when plants don't open their stomata, too much oxygen builds up in leaf tissue. What process is triggered when oxygen binds with rubisco and runs through the Calvin cycle?
photorespiration
500
If the Earth suddenly stopped receiving sunlight, why would life as we know it cease?
Sunlight is required for plants to photosynthesize, providing the world with carbohydrates and oxygen needed for respiration.
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