Bioenergetics - Respiration and Exercise 110-113 Flashcards
what is respiration
the process of transferring energy from the breakdown of glucose which goes in every cell in your body
what type of reaction is respiration
exothermic
how do organisms use the energy transferred by respiration
3 points
1) build up larger molecules from smaller ones - proteins from amino acids
2) in animals it allows muscles to contract
3) in mammals and birds it’s used to keep body temp steady in colder surroundings
give some examples of when larger molecules are made from smaller ones
3 points
1) small glucose molecules join in reactions to form starch, glycogen and cellulose
2) lipid molecules are made from one molecule of glycerol and three fatty acids
3) glucose is combined with nitrate ions to make amino acids which are then made into proteins
give examples of when larger molecules are broken down into smaller ones
2 points
1) glucose is broken down in respiration
2) excess protein is broken down in a reaction to produce urea
what is metabolism
the sum of all of the reactions that happen in a cell or the body
what is anaerobic respiration
the incomplete breakdown of glucose, making lactic acid
when is anaerobic respiration used
when there’s not enough oxygen - e.g. when you do vigorous exercise and your body can’t supply enough oxygen to your muscles
what is the most efficient way to transfer energy from glucose
aerobic respiration
what is the word and symbol equation for respiration
2 points
1) glucose + oxygen → carbon dioxide + water + energy
2) C6H12O6 + 6O2 → 6CO2 + 6H2O
what’s the word equation for anaerobic respiration
glucose → lactic acid
what is bad about anaerobic respiration
3 points
1) it doesn’t transfer nearly as much energy as aerobic because glucose isn’t fully oxidised
2) so it’s only useful in emergencies - vigorous exercise
3) so it allows you to keep using your muscles for a while longer
what is anaerobic respiration in yeast cells called
fermentation
what is the word equation for anaerobic respiration in plant and yeast cells
glucose ⟶ ethanol + carbon dioxide
how is fermentation good for bread making
it’s the CO2 from it that makes bread rise
how is fermentation good for making alcoholic drinks
it’s the fermentation process that produces alcohol
what happens when you exercise
6 points
1) muscles need energy to contract, when you exercise some contract more, so they need more energy
2) the energy comes from increased respiration, this means your cells need more oxygen
3) your breathing rate and volume increase to get more oxygen and your heart rate increases to get the blood round faster - this removes CO2 quicker
4) when you do vigorous exercise your body can’t get O2 quick enough so they respire anaerobically
5) lactic acid builds up in the muscles which hurts
6) long periods of exercise can cause muscle fatigue so they stop contracting efficiently
what is oxygen debt
4 points
1) when you stop exercising you’ll have ‘oxygen debt’ this is the amount of extra oxygen your body needs to react with the build up of lactic acid
2) this means you have to keep breathing hard after exercise
3) your pulse and breathing rate stay high when there’s high lactic acid and CO2 levels
4) the blood can also transport extra lactic acid to the liver where it’s converted back into glucose
