Bioenergetics Flashcards
what is found inside chloroplasts
a pigment called chlorophyll
what does chlorphyll use its energy for
photosynthesis
light
carbon dioxide+water —-> glucose+oxygen
6co2+6h2o > c6h12o6 +6o2
what are the 5 things glucose is used for
cellular respiration
glucose into cellulose(strengthens cell walls
glucose into starch(long term storage and insoluble and is easily broken down when needed)
glucose into amino acids(for proteins)
glucose into oils and fats(future energy source)
How do plants get the water required for photosynthesis?
It diffuses from the soil into the root hair cells by osmosis
what are 4 factors that affect the rate of photosynthesis
light intensity
temperature
chlorphyll amount
carbon dioxide conc in air
what affects the amount of chlorophyll in an individual plant
disease
envronmental stress
lack of nutrients
what are the limiting factors for photosynthesis
light intensity
co2
temperature
describe the graphs for light intensity/level of co2 and temp against rate of photosynthesis
light-increases steadily but plateaus as it is no longer limiting factor
co2-same as light
temp-increases steadily initially due to enzymes gaining more kinetic energy but rate starts to drop as enzymes denature.By 45 degrees enzymes are fully denatured so rate is 0
how do farmers artificially create conditions required for photosynthesis and pros and cons
-greenhouses(trap suns heat and increase temp
they also produce artificial light so photosynthesis can continue at night
-pump co2 or use parrafin heaters(releases heat or co2 into the greenhouse)
them being enclosed means pests and pathogens cant get in as easily
-fertilisers
-pesticides
this can cost a lot so farmers have to weigh extra cost vs extra yield
what is the inverse square law
light intensity is directly proportional to 1/distance between light source and object squared
Explain graph of temperature against rate of photosynthesis
Rate initially increases with temperature…
…because particles have more energy and move faster, so react more frequently
Highest rate is at optimum temperature for enzyme
At higher temperatures the rate decreases as bonds holding the enzyme together begin to break, and so the enzyme changes shape
Rate falls to zero as enzymes denature
what is cellular respiration
breaking apart glucose molecules to release energy stored inside
what are 3 ways organisms/cells use energy
-making larger molecules from smaller
-maintaining body temp
-muscular contractions so we can move
what is metabolism
all chemical processes that occur within an organism for it to survive
When does aerobic respiration take place
-takes place in presence of oxygen in the mitochondria continously
what is the word equation for aerobic respiration
glucose+ oxygen ——> carbon dioxide +water
c6h12o6+ 6o2 —-> 6co2 + 6h2o
when do we do anaerobic respiration
when we are sprinting for example and we our body cant get enough oxygen to our tissues to keep up with the demand of aerobic respiration
what is the equation for anaerobic respiration
glucose——->lactic acid
why do we prefer not to use anaerobic respiration
1)Incomplete breakdown of glucose as there is no oxygen to oxidise it making it inefficient as we do not unlock all the energy inside the glucose molecule-less energy released than aerobic
2)lactic acid builds up which can damage cells and leads to an oxygen debt
in plants and yeast what is the equation for anaerobic respiration
glucose—–>ethanol +carbon dioxide
what does our body have to do when we exercise
carry out more cellular respiration as we have to use muscles much more often than usual
what does increased cellular respiration do/need
more oxygen to our muscles so rate of breathing must increase and volume of breath must also
this means more energy is needed to move the muscles around our lungs
and blood needs to be pumped around our body quicker than usual so heart rate must increase requiring even more energy
what is an oxygen debt and how do we repay it
the oxygen needed to react with the lactic acid which builds up in tissues after exercise
when we pant after a race
how does the lactic acid get oxidised
blood carries it from the muscles to the liver where it reacts with oxygen and is converted back to glucose
how can we investigate effects of exercise on the body
-breathing rate -count how many times chest rises and falls in a given time
-heart rate-measure pulse
design an experiment on the effects of exercise on the body
take pulse before then take it after 5 mins 10 15 and 20 mins of running on a treadmill at the same speed
after each segment measure final heart rate and give a minute rest before measuring
body mass group, their lifestyle, their age group should all be the same
control external factors that affect heart rate (eg coffee intake)
plot time of exercise (x axis)against change in heart rate(y axis)
