Chapter 8

Question 1

where does photosynthesis take place?

Answer 1

in the leaves of plants, in chlorophyll in chloroplasts

Question 2

what happens during photosynthesis?

Answer 2

energy from the light is used to turn carbon dioxide and water into glucose and oxygen

Question 3

what is the equation for photosynthesis?

Answer 3

carbon dioxide + water -(light)-> glucose + oxygen

Question 4

chemical formula for glucose

Answer 4

C6 H12 O6

Question 5

is photosynthesis an endo or exo thermic reaction?

Answer 5

endothermic

Question 6

why is photosynthesis an endothermic reaction?

Answer 6

it requires energy to break the bonds between the CO2 and H20

Question 7

how are leaves adapted for photosynthesis? (5)

Answer 7

large SA
very thin
chlorophyll in the chloroplasts on the upper side of leaf
veins to give the cells nutrients they need and to remove waste products
air spaces allow CO2 to reach all cells

Question 8

why would a photosynthesising leaf turn iodine blue black?

Answer 8

starch is made up of simple sugars like glucose

Question 9

relationship between starch and glucose?

Answer 9

carbohydrates like starch are made up of simple sugars like glucose

Question 10

limiting factors of photosynthesis (3)

Answer 10

light
temperature
CO2 concentration

Question 11

how is light a limiting factor of photosynthesis

Answer 11

when there is no light, the cells can’t get the energy they need to turn the reactants into products

Question 12

how is temperature a limiting factor of photosynthesis?

Answer 12

an increase of temperature will increase the rate of reaction
photosynthesis is controlled by enzymes so a very high temperature will denature them

Question 13

how is carbon dioxide a limiting factor for photosynthesis?

Answer 13

plants need CO2 for photosynthesis

too little CO2 means photosynthesis can’t take place

Question 14

when is CO2 a limiting factor and why?

Answer 14

in the day
at night plants respire but don’t photosynthesise = more CO2
in the day, plants photosynthesise and respire = less CO2

Question 15

why is chlorosis so bad for plants?

Answer 15

the yellow colour means there is no chlorophyll for photosynthesis so the plant can’t grow and therefore dies

Question 16

how do plants use glucose?

Answer 16

to make cellulose for strong cell walls
to get stored as starch 
to get stored in seeds
to get stored as lipids
to make protein

Question 17

why is it better to store glucose as starch?

Answer 17

glucose is soluble in water, meaning it affects the water concentration and therefore osmosis

Question 18

where is starch stored?

Answer 18

roots, stem and leaves

Question 19

how do plants turn sugars into proteins

Answer 19

they combine the sugars with nitrate ions and other nutrients in the soil

Question 20

why can only certain plants, like venus fly traps, live in bogs?

Answer 20

there is no nitrate ions to be turned into protein for growth, so they get it from animals they eat

Question 21

how do greenhouses effect photosynthesis? (2)

Answer 21

they are warm so the process speeds up

the owner can control everything

Question 22

what is hydroponics?

Answer 22

when plants are grown in a solution with optimum nutrients

Question 23

what is different about hydroponics rather than a greenhouse?

Answer 23

in hydroponics, you can control everything

Question 24

How to algae get CO2

Answer 24

Absorb it from the water surrounding them

Question 25

When you get a straight line on a graph of photosynthesis what does this tell you

Answer 25

Something has become the limiting factor

Question 26

What is the light intensity inverse square law?

Answer 26

Light intensity is indirectly proportional to the distance^2

Question 27

What is cellulose used for

Answer 27

Strength

Question 28

What do plants do 24/7

Answer 28

Respite

Question 29

Advantages to hydroponics 3

Answer 29

Less staff needed
Shorter growth time
Larger final crop

Question 30

Disadvantages to hydroponics 3

Answer 30

Expansive monitoring equipment
Alarms if things go wrong
Energy needed to maintain optimum conditions