photosynthesis

Question 1

metabolism

Answer 1

chemical processes in organisms controlled by enzymes

Question 2

anabolism

Answer 2

building up chemical reactions

Question 3

catabolism

Answer 3

breaking down chemical reactions

Question 4

iodine solution

Answer 4

chemical used to test for starch – a positive test results in the
colour changing from brown to blue-black

Question 5

autotrophic

Answer 5

green plants that produce their own food through
photosynthesis

Question 6

heterotrophic

Answer 6

organisms that cannot photosynthesize and obtain food from
other organisms

Question 7

define photosynthesis

Answer 7

the building up of organic compounds (glucose) from CO2 and H2O using radiant energy from the sun trapped by chlorophyll in chloroplasts, oxygen is released as a bi product

Question 8

chloroplast

Answer 8

organelle in plants, site for photosynthesis

Question 9

chlorophyll

Answer 9

green pigment needed for photosynthesis

Question 10

thylakoids

Answer 10

part of the chloroplast that contains chlorophyll

Question 11

grana

Answer 11

stacks of thylakoids, light dependent phase of photosynthesis
takes place here (lig)

Question 12

stroma

Answer 12

liquid part of the chloroplast, light independent phase of
photosynthesis takes place here

Question 13

what are the 6 adaptations of chloroplasts for photosynthesis

Answer 13

1- double membrane = permeable to H2O and CO2 + radiant energy
2- starch granules = temp store starch produced
3- grana made of lamellae (thin flat discs) = give large SA for absorption of sunlight
4- grana contains chlorophyll= trap sunlight
5- stroma contains enzymes= reactions for Dark phase (Das)
6- stroma contains ribosomes = synthesise enzymes for photosynthesis

Question 14

photolysis

Answer 14

splitting of water molecules into oxygen atoms and hydrogen
atoms. photo = light, lysis = split

Question 15

phosphorylation

Answer 15

formation of energy transporting molecules called ATP

Question 16

ATP

Answer 16

adenosine triphosphate, energy carriers in cells

Question 17

Calvin cycle

Answer 17

cyclical process during the light-independent phase of
photosynthesis, aka dark phase, where glucose (C6H12O6) is formed from energy-rich H-atoms combined with CO2 using enzymes like ATP and NADPH

Question 18

glucose

Answer 18

carbohydrate formed during photosynthesis

Question 19

starch

Answer 19

stored form of glucose in plants

Question 20

light phase 5 characteristics

Answer 20

1- Occurs in the grana

2-Light is required

3- chemosynthesis: radiant energy from the sun converted into chemical energy . Radiant energy is absorbed and used for the
reactions of photolysis & phosphorylation

4- Photolysis occurs: splitting of H2O.hydrogen is released and
oxygen is returned to the atmosphere

5- Phosphorylation occurs: ATP is produced

Question 21

5 characteristics of dark phase/ calvin cycle

Answer 21

1- Occurs in the stroma

2- light not req

3- Carbon dioxide is absorbed from
the atmosphere

4- Hydrogen and carbon dioxide
combine by using atp to form
glucose. hydrogen from light phase

5- Excess glucose is stored as starch

Question 22

importance of photosynthesis

Answer 22

1- prov food = trophic levels, transfer of energy. It uses radiant energy to produce chemical potential energy in the form of
glucose which serves as food for other organisms.

2- It balances the levels of carbon dioxide and oxygen in the atmosphere

3- The process uses carbon dioxide and releases oxygen.

Question 23

describe 9 structures of leaf layers, how it helps photosynthesis

Answer 23

1- cuticle= thin layer, 1) thin + transparent, allows light to easily pass through, 2) waxy, reduce water loss

2- epidermis= layer after cuticle, 1)single layer, light easily pass through, 2) transparent

3- palisade mesophyll= 1)contains chloroplasts, max trap of light energy, 2) elongated for deep penetration of radiant energy, 3) thin walls for entry of CO2 and H2O

4- spongy mesophyll= 1) thin walls for entry of CO2 and H2O, 2) chloroplasts trap light energy, 3) irregular shape creates intercellular space betw cells

5- intercellular space = allows for gaseous exchange of CO2 and O2

6- xylem = transp of water and minerals through the plant to cells that req it to make glucose and perform other imp functions

7- phloem= transp products of photosynthesis to keep plant alive

8- stoma= abundant on ventral (bottom) surface for exchange of CO2 and O2, away from sun to reduce water loss via transpiration

9- guard cell = controls opening and closing of stoma