Bio topic 4

Question 1

plants are autotrophic

Answer 1

they make their own food- get energy from sun

Question 2

photosynthesis word eq

Answer 2

Carbon dioxide + Water + (Light Energy) → Glucose + Oxygen

Question 3

photosynthesis element eq

Answer 3

6CO2 + 6H2O → C6H12O6 + 6O2

Question 4

how plants photosythesise

Answer 4

light energy absorbed by chlorophyll in chloroplast in leaf
carbon dioxide in air enters leaves through the
stomata
Water enters the plant through the roots and moves up xylem in transpiration stream to the leaves

Oxygen released as waste product:
-some is used for the plant’s respiration
-some released for respiration to animals

During the day, provided the rate of photosynthesis is sufficiently high, leaves give out oxygen.

Question 5

Biosynthesis

Answer 5

the production of complex molecules within living organisms or cells

Question 6

biosynthesis of glucose in plants

Answer 6

-glucose molecules join t form starch which is an indoluble storage form of carbs
-glucose molecules join to form cellulose to build cell wall
-used for energy for active transport to absorb ions by rhc
-stored as lipids in seeds

Question 7

factors affecting photsynthesis

Answer 7

light intensity
carbon dioxide concentration
temperature
amount of chlorophyll

Question 8

light intensity- photosythesis

Answer 8

-at low light intensity plant photosynthesises slowly
-as increases light intensity rate of pt increases
-till another factor (e.g water) becomes limiting
-the the rate becomes constant

Question 9

Temperature- photosythesis

Answer 9

low temperatures slow rate of photosynthesis as molecules not enough kinetic energy for successful molecular collisions between enzymes and substrates
At high temperatures, enzymes are denatured (change shape) so it doesnt work
.

Question 10

effect of light intensity on photosynthesis can be investigated simple

Answer 10

• pour 45cm^3 sodium hydrogen carbonate into test tube
• place 8cm pondweed inside and cut stem off while submerged
• using a clamp position test tube 10cm away (measures using ruler) from an LED light
• start 1min timer and count the amount of bubbles from stem
• repeat for 20cm, 30cm, 40cm, 50cm, away from LED
• record values

Question 11

how to test effect of chloroplast on photosynthesis

Answer 11

• put leaf of variegated plant in boiling water to kill it
• leave leaf for 10 minutes in hot ethanol in a boiling tube to removes chlorophyll
• dip leaf in boiling water to soften it
• spread out leaf in Petri dish and cover with iodine solution
• areas with chlorophyll stain blue-black due to presence of starch
• areas that had no chlorophyll remain pale

Question 12

what type of reaction is photosynthesis

Answer 12

endothermic as it absorbs light from sun

Question 13

Equation for light intensity

Answer 13

light intensity = 1/ distance^2

Question 14

incresing crop yield

Answer 14

-use greenhouses constructed from glass or alternative materials that enable maximum transmission of light
-position plants for maximum light absorption#
-use paraffin heaters on a small scale
-use carbon dioxide wastes from industrial processes that has been cleaned up before use
-liquid carbon dioxide applied through pipes
-fungi grown as a mycelium to add carbon dioxide through their respiration
-irrigation with water from rivers
-hydroponics is a system that involves growing plants in a porous material

Question 15

aerobic respiration eq

Answer 15

glucose + oxygen → carbon dioxide + water
C6H12O6 + 6O2 → 6CO2 + 6H2O

Question 16

where does aerobic resp happen

Answer 16

mitochondria

Question 17

what kind of reaction is aerobic resp

Answer 17

exothermic

Question 18

why do we respire

Answer 18

-chemical reactions
-movement
-cell division
-homeostasis

Question 19

anaerobic resp eq in animals

Answer 19

glucose → lactic acid + energy released

Question 20

anaerobic resp in yeast eq

Answer 20

glucose → ethanol + carbon dioxide + energy released

Question 21

where does anaeobic resp happen

Answer 21

cytoplasm

Question 22

what is anaeobic resp in yeast used for

Answer 22

-bread
-alcohol

Question 23

when excersizing…

Answer 23

breathing rate and vol of breath increases for more oxygen into body and remove carbon dioxide
the heart rate increases, for more heamoglobic to pump more blood to provide muscles with more oxygen for resp to release energy

Question 24

During long periods of vigorous activity:

Answer 24

lactic acid levels build up
glycogen reserves in muscles become go low as more glucose is used for respiration

Question 25

body stores of glycogen become low

Answer 25

muscles become fatigued

Question 26

aerobic vs anaerobic resp

Answer 26

Aerobic:
o2 is Present
glucose completely oxidised
Produces Carbon dioxide and water
lots of energy released

anaerobic
little o2
incomplete oxidation of glucose
products is lactic acid for animals
product is ethanol and co2 for plants and yeast
little energy released

Question 27

Oxygen debt

Answer 27

amount of extra o2 required by body for recovery after exercise

Question 28

Oxygen debt and the liver

Answer 28

lactic acid needs to be removes after exercise
oxidised to carbon dioxide and water
converted to glucose, then glycogen and stored in liver for future energy

Question 29

metabolism

Answer 29

all the chemical reactions that go on inside an organism’s body.

Question 30

starch - glucose - plants

Answer 30

insoluble energy store of long chain glucose
used as store for plants to use when respiring during night
stored in stem roots and leaves

Question 31

lipids/fats - glucose - plants

Answer 31

produces lipids and oils for storage (e.g seeds)

Question 32

cellulose - glucose - plants

Answer 32

long chains form cellulose to strengthen cell wall

Question 33

nitrates - glucose - plants

Answer 33

glucose combines with nitrate ions from soil to produce amino acids for protein synthesis

Question 34

how to make lipids

Answer 34

1 glycerol + 3 fatty acids

found in cell membrane

Question 35

excess protein

Answer 35

broken down into urea and then excreted by kidney