4-Bioenergetics Flashcards
Is photosynthesis endo or exo thermic
Endothermic as energy is transferred from the environment
What r the reactants of photosynthesis
Carbon dioxide
Water
What r the products of photosynthesis
Glucose and oxygen
How do you balance the photosynthesis symbol equation
666
Put a 6 in front of the CO2, H20 and 02
What five ways do plants use glucose
Respiration Making cellulose Making amino acids Stored as oils and fats (seeds) Stored as starch
What r the limiting factors of photosynthesis
Light intensity
Concentration of CO2
Temperature
Chlorophyll can also be as it be affected by disease
What links light intensity to distance
Light intensity is inversely proportional to the square of distance
eg. if u third the distance, the light intensity will be nine times greater
How can farmers increase the levels of carbon dioxide in a greenhouse
Using a paraffin heater as a by product is CO2
how does increasing light intensity change rate of photosynthesis
The rate increases until a point where it just plateaus
How does levels of CO2 affect the rate of photosynthesis
Increases the rate until a point when it just plateaus
How does temperature affect the rate of photosynthesis
Increases the rate and the rapidly decreases around 45C when the enzymes denature
What plant is used in the practical for showing the effect of light intensity on photosynthesis
Canadian pondweed
Why is an LED used in the required practical for the affect of light intensity on photosynthesis
Because it releases less heat than a filament bulb so the temperature is consistent throughout the practical
How is the volume of oxygen produced measured in the required practical for photosynthesis
It is collected in a capillary tube and at the end it is drawn out with a syringe, where it can be measured.
Alternatively, the bubbles can be counted but this is not very reliable
Is respiration endo or exo thermic
Exothermic
What is respiration
The process of transferring energy from glucose
How do organisms use the energy transferred in respiration
Allows muscles to contract and relax,
Build larger molecules from small ones- proteins from amino acids etc.
Mammals and birds use it keep body temperatures steady in cold surroundings
What is metabolism
The sum of all the reactions in an organism
What r the reactants fro aerobic respiration
Glucose and oxygen
What r the products of aerobic respiration
Carbon dioxide and water
What is the word equation for anaerobic respiration
Glucose —> Lactic acid
Why does anaerobic respiration release less energy than aerobic
Because the glucose isn’t fully oxidised
What is the equation for anaerobic respiration in yeast or plants
Glucose —> ethanol + carbon dioxide
What is anaerobic respiration in yeast cells called
Fermentation
What does build up of lactic acid cause
Muscles fatigue- the muscles stop contracting efficiently
What is oxygen debt
The amount of extra oxygen your body needs to react with the build of lactic acid to remove it from your cells
What does oxygen react with lactic acid to form
Carbon dioxide and water
What other way can the body deal with high levels of lactic acid
Blood transports the lactic acid to liver where it is converted back into glucose
How can you measure the effects of exercise size on the body
Measure breathing rate by counting breaths and heart rate by taking a pulse
