Topic 4 Biogenetics Flashcards
What type of reaction is photosynthesis?
Endothermic
What is the word equation for photosynthesis?
Carbon dioxide + water > glucose + oxygen
What are the 5 ways plants use glucose produced in photosynthesis?
Respiration
Make cellulose
Make amino acids for protein synthesis
Stored as oils/fat
Stored as starch
What is cellulose used for?
Make strong plant cell walls
How do plants make amino acids?
Combine glucose with nitrate ions
Why is glucose stored as starch?
Insoluble- cell with lots of glucose would draw in water and swell up
What are the 4 limiting factors that affect the rate of photosynthesis?
CO2 concentration
Light intensity
Temperature
Chlorophyll amount
What can the amount of chlorophyll be affected by?
Disease or environmental stress (lack of nutrients)
What happens if a plant gets too hot, how does this affect photosynthesis?
Enzymes needed for photosynthesis denature
What type of reaction is respiration?
Exothermic
What are 3 ways organisms use energy transferred by respiration?
Build larger molecules from smaller ones
Muscle contraction
Keep body temp steady
What is the word equation for anaerobic respiration in muscles?
Glucose>lactic acid
Why does anaerobic respiration not transfer as much as energy as aerobic respiration?
Glucose isn’t fully oxidised
What is the word equation for anaerobic respiration in plant and yeast cells?
Glucose > ethanol + carbon dioxide
What is anaerobic respiration in yeast cells called?
Fermentation
Why is fermentation of economic importance?
Used to make bread and alcoholic drinks
Why does the breathing rate and breath volume increase during exercise?
Get more oxygen into blood
Why does the heart rate increase during exercise?
Get oxygenated blood around body faster
What does the incomplete oxidation of glucose/anaerobic respiration cause in the muscles?
Lactic acid build up and oxygen debt
What do long periods of exercise cause?
Muscle fatigue and stop contracting efficiently
What is oxygen debt?
Amount of extra oxygen body needs after exercise to react with accumulated lactic acid and remove from cells
What does oxygen react with lactic acid to form?
CO2 and water
Why does the pulse and breathing rate stay high for a while after exercise?
Repay oxygen debt
What does the blood do to deal with high levels of lactic acid?
Blood flowing through muscles transports lactic acid to liver where it’s converted back to glucose
What is metabolism?
Sum of all chemical reactions in cell/body
What are lipid molecules formed from?
One molecule glycerol and three molecules fatty acids
What are 2 examples of reactions where larger molecules are broken down into smaller molecules?
Glucose in respiration
Excess protein to urea for excretion
What are 3 examples of reactions where larger molecules are made from smaller molecules?
Conversion of glucose to starch/glycogen/cellulose
Lipid molecule formation
Amino acid then protein formation
What is the relationship between light intensity and distance?
Inversely proportional
What is the formula for the inverse square law?
Light intensity = 1/distance (squared)
How do greenhouses help to make sure the temperature doesn’t become limiting?
Trap suns heat
What do commercial farmers do after the sun goes down to give their plants more quality photosynthesis time?
Supply artificial light
How do farmers/gardeners increase the level of carbon dioxide in the greenhouse?
Use paraffin heater, as paraffin burns makes CO2 as by-product
What can farmers add to the soil to provide all the minerals to plants for healthy growth?
Fertilisers
Why are limiting factors important in the economics of enhancing the conditions in greenhouses?
Gain maximum rate of photosynthesis whilst maintaining profit
