Photosynthesis

Question 1

Photosynthesis word eq

Answer 1

Carbon dioxide + water = glucose and oxygen

Question 2

Photosynthesis symbol eq

Answer 2

6CO2+6H2O = C6H12O6+6O2

Question 3

Endothermic reaction

Answer 3

Chemical reactions where reactants absorb energy from surroundings to form products. Light energy is absorbed in the process of photosynthesis

Question 4

What do leaves need to photosynthesise

Answer 4

• Large surface to absorb light
• Chloroplasts containing chlorophyll
• A supply of water and carbon dioxide
• A system for carrying away the products of photosynthesis

Question 5

Why are stomata on the lower epidermis

Answer 5

Less water will be lost through evaporation as the lower epidermis is shaded

Question 6

Upper Epidermis

Answer 6

Protective layer of cells that produces the waxy cuticle

Question 7

Palisade Layer

Answer 7

Main photosynthetic layer with many chloroplasts

Question 8

Spongy Mesophyll Layer

Answer 8

Have air spaces to allow CO2 to diffuse through

Question 9

Veins

Answer 9

Made of xylem and phloem - xylem carrying water and phloem carrying sugars

Question 10

Guard cell

Answer 10

Opens and closes to let CO2 in but not out. Opens when there is lots of water, closes when there isn’t

Question 11

Stoma(ta)

Answer 11

Main photosynthetic layer with many chloroplasts

Question 12

Air space

Answer 12

Space for gases to travel through the leaf

Question 13

Many chloroplasts

Answer 13

Absorbing as much sunlight as possible for photosynthesis

Question 14

Waxy cuticle

Answer 14

Reduces the water loss from the leaf surface

Question 15

Limiting factors of photosynthesis

Answer 15

Temperature, Carbon dioxide concentration, Light intensity and wavelength, Chlorphyll levels in the plant

Question 16

Temperature graph

Answer 16

Particles gain more kinetic energy leading to more frequent collisions between substrate and active site. Therefore the rat increases until optimum temperature for enzymes is reached. After this enzymes begin to denature so the active site changes shape and can no longer fit the substrate

Question 17

Carbon Dioxide Concentration graph

Answer 17

Increased rate - as co2 conc rises so does photosythesis rate - means co2 is limiting factor
after a certain point, rise in co2 has no effect meaning light or temp must be the limiting factor

Question 18

Light Intenisty graph

Answer 18

same as co2

Question 19

wavelength effect on plants

Answer 19

Plants reflect green light and absorb red and blue light. If the plant does not recieve enough blue and red, photosynthesis will be affected

Question 20

Chloropyll effect

Answer 20

If chlorophyll is limited, less photosynthesis will take place
w/o enough minerals e.g. magnesium, it cannot make chlorophyll - rate drops

Question 21

Greenhouses (photosynthesismaxxing)

Answer 21

Commercial growers use greenhouses to take control of limiting factors.

Question 22

Hydroponics

Answer 22

Practice of growing plants in a bath or a flow of highly oxygenated, nutrient enriched water without any soil
Water is kept flowing to circulate minerals to the roots
Water is well oxygenated so roots can respire, producing the energy needed to take up the minerals by active transport

Question 23

Pros of hydroponics

Answer 23

Crops are clean and soil free, can be grown where land is poor, no need to prepare land, requires less labour, can adapt mineral content, space max, faster growing

Question 24

How plants use glucose - respiration

Answer 24

Glucose is broken down using oxygen to provide energy for plant and algal cells to respire. Co2 and water are waste products

Question 25

How plants use glucose - cellulose

Answer 25

Plants build up glucose into complex carbs e.g. cellulose used to strengthen cell walls

Question 26

How plants use glucose - starch

Answer 26

Plants convert some glucose into starch to be stored as starch is insolube and wont affect osmosis. Found in cells all over plant as an energy store in leaves, bulbs, tubers

Question 27

How plants use glucose - lipids

Answer 27

Glucose and energy is used to build up fats and oils - may be used in cells as an energy store, oftne in seeds providing food for the new plant to respire as it germinates

Question 28

How plants use glucose - nitrates, proteins, carnivorous

Answer 28

Plants use glucose to make amino acids by combning sugars with nitrate ions and other mineral ions, these can then be built up into proteins to be used in many ways e.g. enzymes, this uses energy from respiration. Very few plants can survive in low mineral soil. Some obain nutrients from animals/insects that are trapped