GCSE AQA Biology - Topic 4 - BIOENERGETICS Flashcards
word equation for photosynthesis
carbon dioxide+ water -> oxygen + glucose
symbol equation for photosynthesis
6CO2 + 6H2O -> C6H12O6 + 6O2
4 factors that can affect the rate of photosynthesis.
LIGHT
CONCENTRATION
TEMPERATURE
CHLOROPHYLL
describe AND explain the graph of temperature versus rate of photosynthesis.
as the temperature increases the rate of photosynthesis increases until optimum temperature is reached and the rate levels off. As the temperatures continues to rise the enzymes start to denture so rate decreases until it stops completely
describe AND explain the graph of light intensity versus rate of photosynthesis.
as the light intensity increases the rate of photosynthesis increases until either carbon dioxide concentration or temperature become the limiting factor and the rate of photosynthesis levels off even though the light intensity continues to increase.
describe AND explain the graph of carbon dioxide level versus rate of photosynthesis.
as the CO2 concentration increases the rate of photosynthesis increases until either light intensity or temperature become the limiting factor and the rate of photosynthesis levels off even though the CO2 concentration continues to increase.
describe the relationship between light intensity and distance.
when the lamp is closer to the plant the light intensity is higher, but as the lamp is moved further away the light intensity decreases
name the law that is used to link light intensity and distance.
the inverse square law
give the equation that shows the relationship between light intensity and distance.
light intensity = 1 / distance squared
give 5 uses of the glucose made in photosynthesis
RESPIRATION
MAKING CELLULOSE
MAKING AMINO ACIDS
STORED AS OILS OR FATS
STORED AS STARCH
what is respiration
the process of transferring glucose into energy
why is respiration EXOthermic
because it transfers energy to the environment
the energy transferred in respiration is used for all living processes
give 3 examples
TO BUILD UP LARGER MOLECULES
TO ALLOW MUSCLES TO CONTRACT
TO KEEP THE BODY TEMPERATURE STEADY
what is aerobic respiration
respiration using oxygen
what is the word equation for aerobic respiration
glucose + oxygen -> carbon dioxide + water (+ ENERGY)
what is the symbol equation. for aerobic respiration?
C6H12O6 + 6O2 -> 6CO2 + 6H2O (+ ENERGY)
where do most of the reactions for aerobic respiration occur?
inside mitochondria
what is anaerobic respiration
respiration without oxygen
when does anaerobic respiration take place in muscles
when you do vigorous exercise and your body is unable to supply oxygen quickly enough
which type of respiration transfers the least energy
anaerobic respiration transfers the least energy because glucose is not fully broken down
give a word equation for anaerobic respiration in muscles
glucose -> lactic acid (+ ENERGY)
give a word equation for anaerobic respiration in plants and yeast
glucose -> ethanol + carbon dioxide (+ ENERGY)
what is anaerobic respiration in yeast cells called
fermentation
why do you need more energy when you exercise
because exercise requires your muscles to be able to contract and relax to allow movement, this requires energy
describe what happens to the heart rate, breathing rate and breathing volume during exercise and explain why this happens.
- more oxygen and glucose needed in muscles for faster rate of respiration
- faster breathing rate and deeper/bigger breathing volume supplies more oxygen
- faster heart rate pumps blood more quickly to carry oxygen from lungs and glucose from intestines to muscles
what is meant by the term oxygen debt
when you finish exercising anaerobically you continue breathing faster because you need to break down the toxic lactic acid that was made, which requires oxygen
describe the role of oxygen in the removal of lactic acid from the muscles
oxygen oxidises lactic acid breaking it down into carbon dioxide and water
what is metabolic rate
the rate at which all the chemical reactions take place in the body
