3.5 : Energy transfers in and between organisms Flashcards
PHOTOSYNTHESIS:
What is a metabolic pathway?
A series of small reactions controlled by enzymes.
PHOTOSYNTHESIS:
What is phosphorylation?
Adding phosphate to a molecule e.g ADP is phosphorylated to ATP.
PHOTOSYNTHESIS:
What is photo phosphorylation?
Adding phosphate to a molecule using light.
PHOTOSYNTHESIS:
What is photolysis?
The splitting (lysis) of a molecule using light (photo) energy.
H2O -> 1/2 O2 + 2e- + 2H+
PHOTOSYNTHESIS:
What is photo ionisation?
The light energy “excites” the electrons in an atom or a molecule, giving them more energy and causing them to be released.
Release of electrons causes an atom/ molecule to become a + charged ion.
PHOTOSYNTHESIS:
What is decarboxylation?
The removal of CO2 from a molecule.
PHOTOSYNTHESIS:
What is dehydrogenation?
The removal of hydrogen from a molecule.
PHOTOSYNTHESIS:
What is redox reactions?
Reaction that involves OIL RIG.
PHOTOSYNTHESIS:
Where does photosynthesis take place?
Occurs in the leaf.
Chloroplasts are the cellular organelles within the leaf where photosynthesis takes place.
PHOTOSYNTHESIS:
What is the stroma and what does it consist of?
Fluid filled matrix.
Starch and enzymes.
PHOTOSYNTHESIS:
What is the thylakoid disc?
A system of interconnected, flattened fluid filled sacs with protein embedded in the membranes.
PHOTOSYNTHESIS:
What is the function of the starch grain?
Stores the product of photosynthesis.
PHOTOSYNTHESIS:
What structural features of thylakoid increase the rate of photosynthesis?
Stacked into granum.
Increased SA.
Increase absorption of light in the membrane.
PHOTOSYNTHESIS:
What is the role of grana?
Stacks of up to 100 thylakoids.
PHOTOSYNTHESIS:
Where does the light dependent stage of photosynthesis take place?
Thylakoids.
PHOTOSYNTHESIS:
What are the two photosynthetic pigments called?
Chlorophyll.
Carotenoids.
Located on the chloroplast’s thylakoid membrane.
PHOTOSYNTHESIS:
What are the names and colours of the pigment for chlorophyll?
Chlorophyll a -> yellow-green
Chlorophyll b -> blue-green
Reflect green, absorb red light
PHOTOSYNTHESIS:
What are the names and colours of the pigment for carotenoids?
B carotene -> orange
Xanthophyll-> yellow
Reflect orange/yellow, absorb blue light.
PHOTOSYNTHESIS:
What colour of the pigment is absorbed and reflected?
Reflected: green wavelengths } why plants are green in colour.
Absorbed: mainly red and blue.
PHOTOSYNTHESIS:
Oxidation:
Loss of e- and hydrogen.
Gain of O2.
PHOTOSYNTHESIS:
Reduction:
Gain of e- and hydrogen
Loss of O2
