food supply, plant growth and productivity 3.1

Question 1

what is absorption?

Answer 1

the process by which light is taken and retained by a leaf

Question 2

what is an absorption spectrum?

Answer 2

a display/ graph showing the quantity of light absorbed by a pigment at different wavelengths of light

Question 3

what is an action spectrum?

Answer 3

a graph showing the rate of photosynthesis by a green plant at different wavelengths of light

Question 4

what are carbohydrates?

Answer 4

large group of organic compounds that contain carbon, hydrogen and oxygen

Question 5

what are carotenoids?

Answer 5

yellow pigments which absorb light and pass the energy to chlorophyll

Question 6

what are chlorophylls?

Answer 6

green pigments which absorb light in the red and blue regions of the white light spectrum

Question 7

what is chromatography?

Answer 7

a technique used to separate the components of a mixture that differ in their degree of solubility in a solvent

Question 8

what is cultivar?

Answer 8

the variety of plant obtained from natural species by selection and/ or genetic manipulation and maintained by cultivation

Question 9

what is food security?

Answer 9

the ability to access food of adequate quantity and quality

Question 10

what is a nanometre?

Answer 10

one thousands-millionth of a meter ( x10^-9)

Question 11

what is photosynthesis?

Answer 11

the process by which green plants trap light energy and use it to produce carbohydrates

Question 12

what is reflection?

Answer 12

the process by which light bounces off a leaf surface

Question 13

what is transmission?

Answer 13

the process by which light passes through a leaf

Question 14

what is a trophic?

Answer 14

a term referring to a level in a food chain or pyramid

Question 15

what is ATP?

Answer 15

a high energy compound which provides the energy needed to drive the Calvin cycle

Question 16

what is ATP synthase?

Answer 16

the enzyme which catalyses the synthesis of ATP from ADP and Pi

Question 17

what is the calvin cycle?

Answer 17

the second stage of photosynthesis during which carbon dioxide is taken up and sugar is synthesised

Question 18

what is carbon dioxide?

Answer 18

a raw material which supplies carbon atoms to be fixed into carbohydrates

Question 19

what is an electron transport chain?

Answer 19

a group of protein molecules in the membrane of a chloroplast which makes energy available to pump H+ across the membrane and to split water molecules

Question 20

what is glyceraldehyde-3-phosphate? (G3P)

Answer 20

a metabolite in the calvin cycle used to regenerate RuBP and make sugar

Question 21

what is hydrogen?

Answer 21

a product of photolysis of water which becomes attached to NADP

Question 22

what is a light-dependent reaction?

Answer 22

the first stage of photosynthesis during which light energy is converted to chemical energy

Question 23

what is NAPD?

Answer 23

a compound which accepts hydrogen released during the photolysis of water

Question 24

what is oxygen?

Answer 24

a product of photolysis of water which is required for aerobic respiration

Question 25

what is photolysis?

Answer 25

the breakdown of water during the light- dependent state of photosynthesis

Question 26

what is ribulose biphosphate? (RuBP)

Answer 26

a metabolite in the calvin cycle which acts as the carbon dioxide acceptor

Question 27

what is rubisco? (RuBisCO)

Answer 27

an enzyme which fixes carbon dioxide by attaching it to RuBP

Question 28

what is water?

Answer 28

a raw material which becomes split into oxygen and hydrogen during photolysis