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What is the main purpose of the light-dependent reactions?
To capture light energy and convert it into chemical energy (ATP and NADPH)
What happens when light hits chlorophyll?
Electrons in chlorophyll become excited (gain energy)
What process splits water molecules during the light-dependent reactions?
photolysis (hydrolysis)
What molecule is produced that carries high-energy electrons to the next stage?
NADPH
What membrane is directly involved in the light-dependent reactions?
thylakoid membrane
Where do the light-dependent reactions take place in the chloroplast?
Thylakoid membrane
What happens to electrons in chlorophyll when they absorb energy?
They move to a higher energy level and leave the chlorophyll
What are the products of water splitting?
Oxygen, H+ ions, and electrons
What does ATP stand for?
Adenosine triphosphate
What is the stroma?
Inside of the chloroplast (The fluid-filled space surrounding the thylakoids)
What structure inside the chloroplast contains chlorophyll?
thylakoids (photosystems)
What is the electron transport chain?
A series of proteins that transfer electrons to do something (pump H+ or make NADPH)
Why is water essential for the light-dependent reactions?
It replaces electrons lost by chlorophyll and provides hydrogen ions
What does NADPH do in photosynthesis?
Carries high-energy electrons to the Calvin Cycle
Why are the light-dependent reactions called “light-dependent”?
Because they require light to occur
What is the function of chlorophyll in the light-dependent reactions?
to absorb light energy
Why is the electron transport chain important?
It helps produce NADPH and pump H+ (which eventually makes ATP)
What gas is released as a byproduct of the light-dependent reactions?
Oxygen gas or O2
What are thylakoids?
Flattened, disc-like sacs inside chloroplasts
What would happen if a plant did not receive sunlight?
The reactions would stop, so ATP and NADPH would not be produced
What type of energy is absorbed during the light-dependent reactions?
light energy (sunlight), photons
What molecule provides electrons to replace those lost by chlorophyll?
water
What energy-carrying molecule is produced that cells use for energy?
ATP
What is a granum?
How do the products of the light-dependent reactions support the light-independent reactions (Calvin Cycle)?
ATP provides energy and NADPH provides high-energy electrons for the Calvin Cycle