lecture 9 - photosynthesis Flashcards
Where does photosynthesis occur in a plant cell?
Chloroplast
What is the equation for photosynthesis?
6CO2 + 6H2O -> (plant,light) C6H12O6 + 6O2
What are the reactants in photosynthesis?
6 Carbon dioxide, 6 water
What are the products of photosynthesis?
1 glucose, 6 oxygen
How many membranes do chloroplasts have?
3
What are the three membranes of a chloroplast?
Outer, inner, thylakoid
What are the three compartments of a chloroplast?
Inter membrane space, stroma, thylakoid space.
Where are chlorophyll/other pigments contained in a chloroplast?
In the thylakoid
What is a key structural feature of the thylakoid?
It contains a highly folded thylakoid membrane
What is the goal of the light reaction?
To capture light energy and convert it to chemical energy. (ATP)
What are the key components in the membrane involved in the photosynthetic electron transport chain?
Photosystem II, cytochrome complex, Photosystem I, ATP synthase
Where do the electrons in the photosynthetic electron transport chain come from?
The splitting of water molecules, which produces oxygen, H+ ions and electrons
What is the equation for the splitting of water in the photosynthetic electron transport chain?
H2O is converted to 1/2 O2 and 2H+ and 2e-
What occurs at Photosystem II in the photosynthetic electron transport chain?
A pigment (chlorophyll) absorbs light energy, releasing high energy electrons which chemical energy.
How many electrons enter/exit photosystems in the photosynthetic electron transport chain?
2
What occurs at the cytochrome complex?
High energy electrons lose energy by transferring it to allow H+ to move against its concentration gradient, across the thylakoid membrane into the thylakoid space.
What occurs at Photosystem I in the photosynthetic electron transport chain?
Electrons that have lost energy at the cytochrome complex are re-energised by light energy, via chlorophyll pigment absorption.
Where do high energy electrons go to after they leave Photosystem I in photosynthetic electron transport chain?
To enzymes in the cell membrane that add them to carrying molecules - NADP+ - forming NADPH
Where is NADPH formed in the photosynthetic electron transport chain?
At enzymes in the membrane that accept high energy electrons
What occurs at ATP synthase in the photosynthetic electron transport chain?
H+ move down their concentration gradient (energy-less) from thylakoid space to stroma, facilitating the formation of ATP from ADP + P.
What is produced in the photosynthetic electron transport chain?
6O2 as well as ATP and NADPH
What is the reactant that is used up in the photosynthetic electron transport chain?
6H2O
What products of the photosynthetic electron transport chain are used by the Calvin cycle?
NADPH and ATP
What photosynthesis reactant is reacted in the Calvin cycle?
6CO2
What is the other name for the Calvin Cycle?
Carbon fixation
Where does the Calvin cycle occur?
The stroma of a chloroplast
Where does the photosynthetic electron transport chain take place?
The thylakoid membrane
What are the 3 steps of the Calvin Cycle?
Fixation, Reduction,Regeneration
What is the reactant used in the Calvin Cycle?
3CO2
What is the process of fixation in the Calvin Cycle?
A 5 carbon molecule combines with CO2 to form 2 3 carbon molecules.
What is the process of reduction in the Calvin cycle?
A 3 carbon molecule is converted into a different 3 carbon molecule. Energy is used up - 6ATP converted to ADP. 6 NADPH to 6NADP+
How much ATP is used up in the reduction phase of the Calvin Cycle?
6ATP
How much NADPH is converted in the reduction phase of the Calvin Cycle?
6NADPH
How much ATP is used up in the regeneration phase of the Calvin Cycle?
3ATP
How many turns of the Calvin cycle are required to produce Glucose?
6
What is glucose formed from in the Calvin Cycle?
3-carbon sugars
What is the photosynthesis reactant and product of the Calvin Cycle?
6CO2 and C6H12O6 (glucose)
What protein is ATP generated in, in both animal and plant cells?
ATP synthase
Where is ATP synthase in an animal cell?
The inner membrane of the mitochondria
Where does ATP synthase sit in plant cells?
The thylakoid membrane
What is the origin of chloroplasts and mitochondria?
They originated as prokaryotes with aerobic or photosynthetic functions, and were engulfed by eukaryotes until they became essential for cell function, forming chloroplasts and mitochondria
What is a stack of thylakoids?
A granum (plural grana)
What is the size of a chloroplast?
5-7µm
Where is NADP+ formed into NADPH and what type of chemical process is it?
Reduction (electron gain) occurs at NADP+ reductase
Where are protons pumped from and to in photosynthesis?
