Photosynthesis & Respiration Flashcards
Define photosynthesis
The process where energy from light is used to make glucose from water and carbon dioxide which are simple inorganic molecules
Define autotrophs
Organisms that are able to carry out photosynthesis and use simple inorganic molecules to synthesize complex organic molecules
E.g. plants and algae
Define heterotrophs
Organisms which obtain organic molecules by digesting and absorbing complex organic molecules
Where does the light independent stage take place?
Stroma
Where does the light dependent stage take place?
Thylakoid
What are photosynthetic pigments?
Chemicals that absorb light energy, found in the thylakoid membranes of chloroplasts
Why do plants have several photosynthetic pigments?
So they can absorb more wavelengths of light for the light dependent stage
Give 4 examples of chlorophyll molecules
Chlorophyll a + b
Carotene
Xanthophyll
what do photosystems consist of?
2 types of photosynthetic pigments
primary and accessory pigment
define primary pigment
reaction centres where electrons are excited and emitted to higher energy levels during the light dependent reaction
what do co-enzymes do?
aid the function of enzymes
give the name and function of the important co-enzyme in photosynthesis
NADP
it transfers hydrogens (protons) from one molecule to another
what happens in the light dependent reaction
1-chlorophyll absorbs light energy
2-electrons become excited and are emitted from chlorophyll
3-electrons are accepted and move down the electron transport chain releasing energy
4-energy is used to pump H+ from stroma to thylakoid lumen
5- H+ diffuse back into stroma through ATP synthase down electrochemical gradient forming ATP from ADP+Pi
6- photolysis of water produces proton, electrons and oxygen
7-NADP becomes reduced by electrons and H+
whats chemiosmosis?
H+ diffuse back into stroma through ATP synthase down electrochemical gradient
forming ADP + Pi
