bioenergetics Flashcards
what is the equation symbol of photosynthesis
6CO2+ 6H20——> C6H12O6+6O2
photosynthesis produces _______ using __________
glucose using light
how does photosythesis work
- uses enegry to chnage carbon dioxide and water into glucose and oxygen
where does photosythesis take place
cholorpasts in green plant cells
- cholorophyll abosrbs the light
how is enegry transfered to the chloroplasts from the enviroment
through light
is photosythesis endothermic or exothermic
endothermic
what do planst sue glucose for
- respiration
- making amino acids
- making cellucose
- stored as oils or fats
- stored as starch
What is the molecular formula for glucose?
C6H12O6
How do plants get the carbon dioxide required for photosynthesis?
It diffuses from the air into the leaves via stomata
How do plants get the water required for photosynthesis?
It diffuses from the soil into the root hair cells by osmosis
What makes starch a useful long term storage molecule?
It is insoluble in water
It can easily be broken down when needed
It is compact
Which useful energy transfer or conversion happens overall in photosynthesis?
Light ➔ chemical
Why may plants produce insufficient chlorophyll?
They have a disease like Tobacco Mosaic Virus
They lack the required nutrients
these cause chloroplasts to get damaged
what are the factors that affect the rate of photosynthesis
- light intensity
- amount of carbon dioxide
- temperature
- amount of chlorophyll
explain how the rate of photosynthesis varies with temperature.
- photosynthesis rises with temperature as the particles have more energy and move more quickly. This means they can react more quickly
- as temperature rises above the optimum temperature for the enzymes involved, the enzymes may start to break down. This decreases the rate until it falls to zero
How can farmers ensure that photosynthesis takes place 24 hours a day?
artifical light
what are two benefits of parrifan heaters
release
- heat
- carbon dioxide
what is respiration
the process of transferring energy from glucose which goes on in every cell
Is respiration an exothermic or endothermic reaction?
exothermic becuase it relases enegry
Which process in plants produces the glucose required for respiration?
photosnythesis
what are examples about how organisms use the energy transferred by respiration
- muscle contraction
- maintain body temperature
- build up larger molecules from smaller ones
What is the word equation for aerobic respiration?
Glucose + oxygen ➔ carbon dioxide + water
What is glucose converted to during anaerobic respiration in animals?
lactic acid
what is the word equation of anarobic repiration in plants and fungi
Glucose ➔ ethanol + carbon dioxide
What are the two reasons animals cells prefer aerobic respiration to anaerobic respiration?
Anaerobic respiration doesn’t break down the glucose molecule completely, and so releases less energy than aerobic respiration
-Anaerobic respiration produces lactic acid which can damage cells and leads to an oxygen debt
Which type of respiration is more efficient, aerobic or anaerobic?
aerobic
Which type of respiration requires oxygen, aerobic or anaerobic?
aerobic
why do muscles need enegry from repiration
to contract
the increase in repsiration in your cells means you need to get more ________ to them
oxygen
why do your breathing increase while doing excersize
to get more oxygen to the blood
why doe syour heart rate increase while doing excersize
to get more oxygen aroun dthe body rapidly - removes CO2 at teh same time more rapidly
what is oxygen debt
the amount of oxygen the body needs to react with the build of of lactic acid to remove it from the body cells
what happens when oxygen reacts with latic acid
forms CO2 and oxygen
what happens when you do vigorous excersize
- body cant supply oxygen fast enough
- start respirating anaerobically
what is anaerobic repsiration not good
lactic acid builds up in muscles which gets painful
was is mucle fatigue
- muscles get tired and stop contracting efficiently
why do we breath hard after stopping vigiorous excerzise
- to get more oxygen into blood to repay oxygen taht didnt get to muscle cells in time - oxygen debt releif
plus and breathing rate stay ____ whist there are high levels or latic acid
high
what is anotehr way that sint debt releif taht the body copes with high levels of latic acid
- blood that enters muscles transports latic acid to liver where it is convereted back to glucose
how can you measure bretahing rate
- counting breaths
- heart rate
hwo can you investigate the effect of excersize on the body?
take pulse after
- 5 mins sitting
- 5 mins gentle walking
- 5 mins jogging
- 5 mins running
- do it in a group to reduce random errors
Which type of respiration leads to the build up of lactic acid, aerobic or anaerobic?
anaerobic
why is a led light source used in a photosynthesis practical
they dont realse much heat - too much heat would change the temperature of the experiment
what are the steps in photosythesis practical
- boiling tube 10cm away from LED light source
- fill boiling tube with water
- pond weed into boiling tube with cut end at top
- pond weed is left to photosythesis for a set amount of time
- as it photosythesises oxygen released will collect in the capillary tube
- end of experiment - syringe used to draw the gas bubbles in tube alongslide a ruler and length of gas bubbles is measured
- repeated twice to calculate mean volume at that distance
- repeated with light source at different distances from pond weed
if you wanted to use a normal light bulb in photosythesis practical what adpatation would you have to make
place beaker of water inbetween light bulb and boiling tube becuase it absorbs the heat
why do we use sodium hydrogen carbonate in photosynthesis practical
- realeases carbon dioxide which is needed for photosythesis
what are issues with photosynthesis practical
- number of bubbles to fast to count
- bubbles are not always same size
what can we do instead of counting bubbles produced in photosynthesis practical
measuring volume of oxygen produced
how to do photosythesis practical
volume of oxygen produced
- palce pond weed under funell and catch bubbles in measuring cylinder full of water
- use measuring cylinder to calculate volume of oxygen produced
how does glucose make ammino acids
it is combined with nitrate ions which are absorbed from the soil to make ammino acids
why do plants store glucose as starch
stored in roots + leaves
- good for in winter when photosythesis isnt happening
- starch in insoluble which makes it better for storing glucose
why is starch better for storing than glocuse
starch is insoluble
- if glucose was stored it would draw in loads of water and the cell would swell up
how can insufficient chlorophyll affect the rate of photosythesis
if not enough chlorophyll is made then not as much light is absorbed
what happens when the light level is raised in photosynthesis
the rate of photosythesis increases until certain point - beyond that point as light intensity increases the rate will no longer increase because temp or Co2 will now become the limiting factor
at what temperature can plants get too hot for the enzymes to be destroyed in photosythesis
45 degrees
what happens if the temperature is too low in photo synthesis
the ezymes needed for photosythesis will work more slowly
what happens when the CO2 levels is raised in photosynthesis
the rate of photosythesis increases until certain point -beyond that point as light intensity increases the rate will no longer increase because temp or light intensity will now become the limiting factor
in the photosynthesis experiment was is the length of gas bubbles measured proportional to
the volume of O2 produced
what is the control variable in photosynthesis practical
temperature of water
size of pond weed
volume of water
what is the independant variable in the photosythesis practical
the light intensity
what is the dependant variable in the photosythesis practical
the number of oxygen bubbles given off
What is the purpose of repeating the experiment at different distances?
to investigate the effect of light intensity on the rate of photosynthesis
how can the photosythesis experiment be altered to find the effect of the temperature on photosythesis
west tube of pond weed put in a waterbath with a set temperature
repeated wthe different temperatures of water
how can the photosythesis experiment be altered to find the effect of the CO2 levels on photosynthesis
a measured amount of sodium hydro carbonate dissolved in the water with pond weed in it
repeated with different concentration
what is the formula for the inverse square law
light intensity = 1/d(distance)^2
what is the most common way to artifically grow plants in ideal enviroments
green houses
what do green houses do
helps trap the suns heats the temperature doesnt become a limiting factor
how might farmers keep ideal temperature in their green houses at winter
use heaters
how might farmers keep ideal temperature in their green houses at summer
use shades or ventilation to cool green house down of too hot
how can farmers increase the levels of carbon dioxide in green houses
paraffin heaters
whats good about green houses
- enclosed so it makes it easier to keep plants from pests
- if conditions are right plants will grow much faster and there will be more crops at harvest which can then be sold
what is metabolism
all the chemical reactions in an organism
in a cell what are chemical reactions controlled by
enzymes
what is aerobic respiration
respiration using oxygen
- most efficent way to transfer energy from photosynthesis
what is the symbol equation for for aerobic repsiration
C6H12O6 + 6O2 -> 6CO2 + 6H20
when is anaerobic respiration used
when your body cant supply enough oxygen to your muscles
e.g vigorous supersize
what is anaerobic respiration
respiration without oxygen
- incomplete breakdown of glucose creating lactic acid
how much energy does anaerobic respiration transfer compared to aerobic respiration
does not transfer nearly as much becuase the glucose isnt fully oxidised
what happens when plants and yeast respire anaerobically
they produce ethanol and carbon dioxide instead of latic acid
what is the word equation for anaerobic respiration in muscles
glucose -> lactic acid
what is anaerobic respiration in yeast cells called
fermentation
why is fermentation good in the food and drinks industry
- in bread making - carbond dioxide from fermentation makes bread rise
- in beer and wine making - fermentation is the process that produces alchohol
why is anarobic repsiration not the best way way to transfer energy from glucose
becuase it produces latic acd which builds up in the muscles which can be really painful
what is muscle fatigue
when muscles get tired and stop contracting efficently
what causes muscle fatigue
exerciseing for long periods of time
Which organ in the body removes the lactic acid from the blood.
liver
