3.5 : Energy transfers in and between organisms

Question 1

PHOTOSYNTHESIS:
What is a metabolic pathway?

Answer 1

A series of small reactions controlled by enzymes.

Question 2

PHOTOSYNTHESIS:
What is phosphorylation?

Answer 2

Adding phosphate to a molecule e.g ADP is phosphorylated to ATP.

Question 3

PHOTOSYNTHESIS:
What is photo phosphorylation?

Answer 3

Adding phosphate to a molecule using light.

Question 4

PHOTOSYNTHESIS:
What is photolysis?

Answer 4

The splitting (lysis) of a molecule using light (photo) energy.

H2O -> 1/2 O2 + 2e- + 2H+

Question 5

PHOTOSYNTHESIS:
What is photo ionisation?

Answer 5

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.

Question 6

PHOTOSYNTHESIS:
What is decarboxylation?

Answer 6

The removal of CO2 from a molecule.

Question 7

PHOTOSYNTHESIS:
What is dehydrogenation?

Answer 7

The removal of hydrogen from a molecule.

Question 8

PHOTOSYNTHESIS:
What is redox reactions?

Answer 8

Reaction that involves OIL RIG.

Question 9

PHOTOSYNTHESIS:
Where does photosynthesis take place?

Answer 9

Occurs in the leaf.

Chloroplasts are the cellular organelles within the leaf where photosynthesis takes place.

Question 10

PHOTOSYNTHESIS:
What is the stroma and what does it consist of?

Answer 10

Fluid filled matrix.

Starch and enzymes.

Question 11

PHOTOSYNTHESIS:
What is the thylakoid disc?

Answer 11

A system of interconnected, flattened fluid filled sacs with protein embedded in the membranes.

Question 12

PHOTOSYNTHESIS:
What is the function of the starch grain?

Answer 12

Stores the product of photosynthesis.

Question 13

PHOTOSYNTHESIS:
What structural features of thylakoid increase the rate of photosynthesis?

Answer 13

Stacked into granum.
Increased SA.
Increase absorption of light in the membrane.

Question 14

PHOTOSYNTHESIS:
What is the role of grana?

Answer 14

Stacks of up to 100 thylakoids.

Question 15

PHOTOSYNTHESIS:
Where does the light dependent stage of photosynthesis take place?

Answer 15

Thylakoids.

Question 16

PHOTOSYNTHESIS:
What are the two photosynthetic pigments called?

Answer 16

Chlorophyll.
Carotenoids.

Located on the chloroplast’s thylakoid membrane.

Question 17

PHOTOSYNTHESIS:
What are the names and colours of the pigment for chlorophyll?

Answer 17

Chlorophyll a -> yellow-green

Chlorophyll b -> blue-green

Reflect green, absorb red light

Question 18

PHOTOSYNTHESIS:
What are the names and colours of the pigment for carotenoids?

Answer 18

B carotene -> orange

Xanthophyll-> yellow

Reflect orange/yellow, absorb blue light.

Question 19

PHOTOSYNTHESIS:
What colour of the pigment is absorbed and reflected?

Answer 19

Reflected: green wavelengths } why plants are green in colour.

Absorbed: mainly red and blue.

Question 20

PHOTOSYNTHESIS:
Oxidation:

Answer 20

Loss of e- and hydrogen.
Gain of O2.

Question 21

PHOTOSYNTHESIS:
Reduction:

Answer 21

Gain of e- and hydrogen
Loss of O2