Bioenergetics Flashcards
photosynthesis equation
carbon dioxide + water -light->
glucose + oxygen
6CO2+6H2O–>C6H12O6+6O2
what type of reaction is photosynthesis?
endothermic as chloroplasts take in light
what factors affect the rate of photosynthesis?
- temp
- light intensity
- CO2 concentration
- amount of chlorophyll
shortage of any of these=photosynthesis can’t occur at maximum rate
how to control limiting factors in a greenhouse?
- greenhouse=traps heat=temp x limit photosynthesis
- x shades on ceiling=maximum light
- artificial light for winter/dark hours= photosynthesis all day round
- ventilation= plants x too hot
- heater burns paraffin=CO2 released=bad for planet
- hydroponics (watering system)= plants well watered
- easier to control pests & diseases+ fertilisers= maximise growth
light intensity equation
inverse square law (light+distance)
- 1/d^2
required practical: light intensity
- Pour 45 cm3 of sodium hydrogencarbonate solution in a boiling tube
- Cut a piece of the pondweed
- Place pondweed into boiling tube carefully to ensure no damage
- Put boiling tube 10 cm away from the light source. Allow the boiling tube to stand for five minutes
- Count the number of bubbles released in one minute. Record results. Repeat 3 times and record your results
- Calculate the average number of bubbles produced per minute
- Repeat the experiment at different distances away from the light source
- Plot results in a graph
what are the uses of glucose in a plant?
- respiration
- converted into insoluble starch for storage
- produce fat or oil for storage
- produce cellulose, which strengthens the cell wall
- combined with nitrate ions in the soil to form amino acids for protein synthesis.
what type of equation is respiration?
exothermic, it release energy for living processes
what are the 2 types of respiration?
aerobic and anaerobic
what do we need energy for?
- movement
- keeping warm
- chemical reactions to build larger molecules
aerobic respiration equation
glucose + oxygen –> carbon dioxide + water
C6H12O6+6O2–> 6CO2+6H2O
anaerobic respiration equation
glucose –>lactic acid
releases less energy
when does anaerobic respiration occur?
intense exercise
not enough oxygen available
what happens during exercise?
- heart rate+breathing rate+breath volume= increase= more oxygenated blood to muscles
- insufficient oxygen suppplied= anaerobic respiration= lactic acid builds up+oxygen debt
- long exercise period=muscles fatigued=muscles x contract efficiently
how do we get rid of lactic acid?
Blood transports lactic acid to
liver where it is converted back into glucose
what is oxygen debt?
amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove it from the cells
anaerobic respiration in plants&fungi (fermentation)
glucose –>ethanol + carbon dioxide
CO2=bread rise
ethanol=alcoholic drinks
what is metabolism?
sum of all the reactions in a cell or the body
examples of metabolic processes
- converting glucose into starch, glycogen and cellulose
- formation of lipid molecule from a molecule of glycerol and three molecules of fatty acids
- use of glucose and nitrate ions to form amino acids which are used to synthesise proteins
- respiration
- breakdown of excess proteins to form urea for excretion
