GCSE Bioenergetics Flashcards
Why are greenhouses useful?
Ability to control CO2 levels, temperature, light intensity, water concentration and mineral ions
Define respiration
An endothermic chemical reaction inside cells that releases energy from glucose
Define metabolism
The sum of all chemical reactions happening inside a cell
Give uses of glucose from respiration in animals
Muscle contraction, maintain steady body temp (mammals & birds), perform anabolic reactions (protein synthesis)
Give uses of glucose from respiration in plants
Creation of cellulose for growth & repair, building amino acids
Give the word equation for anaerobic respiration in animals
Glucose —> 5% ATP of aerobic + lactic acid
Give the word equation for anaerobic respiration in plants + fungi
Glucose —> ATP + ethanol + CO2
Why does temperature raise while exercising?
Excess heat is produced by higher rates of respiration, raising core body temp
Why does heart rate increase when exercising?
To increase the flow of blood to the lungs for increased oxygen uptake. To increase the flow of blood to the muscles to deliver oxygen & glucose for contraction
Why does breath rate increase when exercising?
To increase the amount of oxygen taken into the body and to remove increased amounts of excess CO2 from aerobic respiration
What is oxygen debt?
The amount of oxygen needed to oxidise lactic acid from anaerobic respiration into CO2 and water
When does anaerobic respiration occur in plants?
When the plant cannot access enough oxygen (e.g - waterlogged soil)
What is anaerobic respiration called in yeast?
Fermentation
Give examples of catabolic reactions
Protein + amino acid breakdown
Give examples of anabolic reactions
Lipid + protein synthesis, glucose reactions
Describe how excess protein is broken down
Excess protein is broke down into amino acids, which can diffuse from a high concentration in cells to a low concentration in the blood, to diffuse into the liver to be broken down.
Describe how amino acids are broken down
Once in the liver, enzymes remove an amine group from the amino acids (deamination), forming urea to be excreted by the kidneys
Describe reactions of glucose
Glucose produced during photosynthesis is stored as insoluble starch or made into cellulose for growth + repair. Animals store glucose and glycogen in the liver
Describe the synthesis of lipids
1 glycerol + 3 fatty acids —> lipid
Describe the synthesis of proteins
Glucose + nitrate ions make amino acids. A chain of amino acids folded in a certain was is a protein
