Bioenergetics

Question 1

define photosynthesis

Answer 1

A chemical process used by plants to make glucose and oxygen from carbon dioxide and water, using light energy. Oxygen is produced as a by-product of photosynthesis.

Question 2

define glucose

Answer 2

a simple sugar used by cells for respiration

Question 3

define inorganic molecules

Answer 3

a compound that does not include carbon combined with hydrogen

Question 4

how do plants produce glucose in photosynthesis

Answer 4

from inorganic molecules- carbon dioxide and water, using light energy

Question 5

write the word equation for photosynthesis

Answer 5

carbon dioxide + water —–(light + chlorophyll)– glucose + oxygen

Question 6

write the symbol equation for photosynthesis

Answer 6

(6 CO₂ ) + (6 H₂O) — (light and chlorophyll )— (C₆H₁₂O₆) + (6 O₂)

Question 7

what type of reaction is photosynthesis

Answer 7

an endothermic reaction
(a reaction where energy is taken in)

Question 8

how does light energy required for photosynthesis get absorbed

Answer 8

a green pigment called chlorophyll

Question 9

where is chlorophyll located

Answer 9

in chloroplasts in plant cells, particularly the palisade and spongy mesophyll cells

Question 10

what is the main photosynthetic organ in plants

Answer 10

the leaves

Question 11

define respiration

Answer 11

the chemical change that takes place inside living cells, which uses glucose and oxygen to release the energy that organisms need to live. carbon dioxide is a by-product of respiration

Question 12

define biosynthesis

Answer 12

the production of more complex molecules , from simpler ones, in living organisms

Question 13

why is glucose needed

Answer 13

it is the starting point for the biosynthesis of materials that plants need to live

Question 14

name the ways that glucose that is not used for respiration is used in plants

Answer 14

1. as starch from many glucose molecules joined together- it is insoluble and a storage form of carbohydrate
2. as lipids (fats/ oils)- used for storage in seeds
3. as amino acids from glucose + nitrates which are absorbed from the soil –> and then many amino acid molecules joined together make proteins
   4.as cellulose from many glucose molecules joined together - used to build cell walls and add strength to cell walls

Question 15

how can you measure the rate of photosynthesis

Answer 15

the rate of oxygen output
the rate carbon dioxide uptake
the rate of carbohydrate production

Question 16

name factors that affect the rate of photosynthesis

Answer 16

light intensity
carbon dioxide concentration
temperature
amount of chlorophyll

Question 17

define a limiting factor

Answer 17

A factor which, if in short supply limits or reduces the rate of photosynthesis, eg temperature, light intensity and carbon dioxide concentration

Question 18

what is the chemical reaction that combines carbon dioxide and water to produce glucose controlled by

Answer 18

enzymes

Question 19

why would the rate of photosynthesis change with the time of day

Answer 19

because light intensity is a limiting factor of photosynthesis, and we have day and night

Question 20

what type of lamp is ideal for the required practical

Answer 20

LED because it will not raise the temp of the water

Question 21

what is added to the water in the required practical to supply carbon dioxide

Answer 21

sodium hydrocarbonate

Question 22

what is the light intensity in the required practical proportional to

Answer 22

distance

Question 23

what is the aim of the required practical

Answer 23

to investigate the effect of light intensity on the rate of photosynthesis

Question 24

what is the inverse square law

Answer 24

1/ (distance)²

Question 25

what conditions can be used to increase light intensity?

Answer 25

.use greenhouses that specifically are constructed from glass .and position plant for maximum light absorption .use artificial lighting that has increased light intensity .use artificial lighting that provides optimum wavelengths of light for photosynthesis

Question 26

what conditions can be used to increase carbon dioxide concentration

Answer 26

. use paraffin heaters . use types of fungi grown as mycelium . use liquid carbon dioxide

Question 27

what conditions can be used to increase water supply for photosynthesis

Answer 27

. irrigation systems . grown in hydroponic liquid systems

Question 28

what conditions can be used to keep temperature optimal for photosynthesis

Answer 28

.heat is used inside note that cooling sometimes needs to happen

Question 29

how is carbohydrate stored in plants

Answer 29

as starch

Question 30

what happens when plants do gas exchange

Answer 30

. plants take up oxygen at night . there is a net production of oxygen during the day

Question 31

what molecule is the storage form of carbohydrate in humans

Answer 31

glycogen

Question 32

what is the formula for anaerobic respiration in plants

Answer 32

glucose - > ethanol and carbon dioxide

Question 33

what type of process is respiration

Answer 33

exothermic

Question 34

what is the energy from respiration used for in animals

Answer 34

. to build complex carbohydrates . build proteins . to build lipids . digestion . movement .cell division . homeostasis . active transport . transmission of nerve impulses . in birds and mammals it is used to keep them warm as heat is released and distributed around the body

Question 35

what is the energy released from respiration used for in plants

Answer 35

. for active transport . for driving chemical reactions . cell division

Question 36

define aerobic respiration

Answer 36

respiration that requires oxygen

Question 37

define respiratory substrate and name the molecule that is main respiratory substrate

Answer 37

. a substance broken down by respiration to release energy . glucose

Question 38

name the word equation for aerobic respiration

Answer 38

glucose + oxygen -> carbon dioxide + water

Question 39

in which sub- cellular structure does respiration occur in

Answer 39

mitochondria

Question 40

what happens to glucose so it can release it's energy

Answer 40

it oxidises

Question 41

what is the symbol equation for aerobic respiration

Answer 41

C₆H₁₂O₆ + 6O₂ -->6Co₂ + 6H₂O + energy released

Question 42

where do the first stages of respiration occur and where is most of the energy released from

Answer 42

cytoplasm mitochondria

Question 43

define anaerobic respiration

Answer 43

respiration without oxygen

Question 44

what is the equation of anaerobic respiration in animals

Answer 44

glucose --> lactic acid + energy released

Question 45

where does anaerobic respiration occur

Answer 45

only in the cytoplasm

Question 46

is the oxidation of glucose in anaerobic respiration complete or incomplete

Answer 46

incomplete

Question 47

what happens to the body during exercise and why

Answer 47

. the breathing rate and volume of each breath increases to bring more oxygen into the body and remove co2 . heart rate increases to supply the muscles with extra oxygen and remove co2

Question 48

what happens during long periods of vigorous activity

Answer 48

. lactic acid levels build up . glycogen reserves in the muscles become low as more glucose is used for respiration and additional glucose is transported from the liver

Question 49

what happens when the glycogen stores in the body becomes low during exercise

Answer 49

the person suffers from muscle fatigue

Question 50

what is the livers role in respiration

Answer 50

the liver converts lactic acid back into glucose (the process needs oxygen)

Question 51

what can happen to the lactic acid taken to the liver

Answer 51

.can be oxidised into carbon dioxide and water . converted to glucose, then glycogen - so that the glycogen stores in the liver and muscles can be restored

Question 52

define oxygen debt

Answer 52

the amount of oxygen required to remove the lactic acid and replace the body's reserves of oxygen

Question 53

define metabolism

Answer 53

all the chemical reactions in the cells of an organism , including respiration