Bioenergetics (Photosynthesis and Respiration)

Question 1

what is the main chemical reaction in plants called

Answer 1

photosynthesis

Question 2

photosynthesis converts carbon dioxide and water into?

Answer 2

oxygen and glucose

Question 3

what type of energy is used to power photosynthesis

Answer 3

light energy

Question 4

what is the light energy absorbed by

Answer 4

the green pigment chlorophyll

Question 5

is photosynthesis exothermic or endothermic

Answer 5

endothermic

Question 6

what organelle carries out photosynthesis

Answer 6

chloroplasts

Question 7

how do plants acquire carbon dioxide

Answer 7

through diffusion through the stomata

Question 8

how is water absorbed

Answer 8

through the roots of a plant and carried to photosynthesis cells by the Xylem

Question 9

what is the glucose made in respiration used for

Answer 9

respiration, stored as starch, fats or oils, used to produce cellulose or amino acids for protein synthesis

Question 10

what is a photosynthesis limiting factor

Answer 10

a factor that stops the photosynthesis reaction from
occurring at a faster rate. e.g. temp ,light intensity, CO2

Question 11

what will increasing CO2 concentration do

Answer 11

increase the rate of reaction - there are more reactants available

Question 12

what will increasing light intensity do

Answer 12

increase the rate of reaction because there is more energy to carry out the reaction.

Question 13

what does increasing temperature do

Answer 13

will increase the rate till around 45 degrees where the enzymes catalyse and denature.

Question 14

what is the limiting factor at night

Answer 14

light intensity

Question 15

what is the limiting factor in winter

Answer 15

temperature

Question 16

what is the limiting factor in other conditions

Answer 16

usually CO2

Question 17

why do graphs for limiting factors always plateau

Answer 17

increasing one factor will increase the rate of reaction it then plateau’s because another factor will have become limiting

Question 18

how are greenhouses used to control temperature

Answer 18

a greenhouse traps the suns radiation as heat inside the greenhouse so temperature is controlled

Question 19

how are greenhouses used to control light intesity

Answer 19

artificial lights can be installed to give constant light and therefore energy and it isn’t a limiting factor

Question 20

how are greenhouses used to control CO2

Answer 20

add a paraffin heater which also maintains temp but combustion cause CO2

Question 21

what are the advantages of greenhouse growing

Answer 21

crops are healthier and grown faster - diseases and pests can easily be controlled

Question 22

what are the disadvantages of greenhouse growing

Answer 22

expensive but this is outweighed by advantages

Question 23

what is the inverse square law

Answer 23

the intensity of light is inversely proportional to the square distance of the source

Question 24

using the inverse square now how do you calculate light intensity

Answer 24

light intensity = 1/distance**2

Question 25

what is light intensities units

Answer 25

arbitrary units

Question 26

what is respiration

Answer 26

respiration is a chemical reaction that releases energy for living functions and processes

Question 27

where does respiration occur

Answer 27

the mitochondria of every living cell

Question 28

what are the living functions of respiration

Answer 28

movement, warmth, building larger molecules for growth and repair

Question 29

is respiration exothermic or endothermic

Answer 29

exothermic - energy is released to the surroundings

Question 30

aerobic respiration equation

Answer 30

glucose + oxygen ===> carbon dioxide + water + energy

Question 31

does aerobic respiration use oxygen

Answer 31

yes

Question 32

anaerobic respiration equation

Answer 32

glucose ===> lactic acid + energy

Question 33

does anaerobic respiration use oxygen

Answer 33

no

Question 34

what does it mean when in anaerobic respiration the glucose isn’t fully oxidised

Answer 34

less energy is released than in aerobic respiration

Question 35

what is the anaerobic respiration of yeast equation

Answer 35

glucose ===> ethanol + carbon dioxide + energy

Question 36

what is yeast anaerobic respiration called

Answer 36

fermentation used in bread making and beer brewing

Question 37

what happens to the amount of respiration during exercise

Answer 37

when a person exercises they need more energy so the amount of respiration reactions increase

Question 38

what does the body do to supply more oxygen to the muscles during exercise

Answer 38

the heart pumps faster and the breathing rate and breath volume all increase to supply more oxygen via the bloodstream.

Question 39

if muscles arent receiving enough oxygen what happens

Answer 39

they anaerobically respire producing lactic acid

Question 40

what can happen when muscles are producing lactic acid

Answer 40

lactic acid can build up in the muscles and result in an oxygen debt

Question 41

what is oxygen debt

Answer 41

during exercise the body can respire anaerobically and produce lactic acid
lactic acid is taken to the liver which converts it back to glucose however this uses oxygen
the oxygen debt is the amount of oxygen required by the body to convert the built up lactic acid into glucose and remove it from cells

Question 42

what is metabolism

Answer 42

metabolism is the sum of all the reactions in the body or in a cell

Question 43

what is energy released during respiration used for (metabolic processes)

Answer 43

glucose to starch, glycogen to cellulose,
glycerol and three fatty acids are joined to form a lipid molecule
glucose and nitrate ions form amino acids
amino acids are joined to form proteins
excess proteins are broken down and released in urea

Question 44

is respiration included in metabolic reactions

Answer 44

yes