bioenergetics Flashcards
(20 cards)
What are the equations for photosynthesis?
WORD: carbon dioxide + water -(light)> glucose + oxygen
BALANCED SYMBOL: 6CO2 + 6H2O -> C6H12O6 + 6O2
Is photosynthesis endothermic or exothermic?
Endothermic
What is inverse square law?
Light intensity is inversely proportional to distance squared
Light intensity is proportional to 1/distance squared
apparently??? what the even hell?????
REQUIRED PRACTICAL: rate of potosynthesis
Method:
1.Set up a boiling tube containing 45 cm3 of sodium hydrogencarbonate solution
(1%). Allow the tube to stand for a few minutes and shake to disperse any air
bubbles that might form.
2.Cut a piece of the pondweed, Cabomba. The pondweed should be 8 cm long.
3.Use forceps to place the pondweed in the boiling tube carefully. Make sure that
you don’t damage the pondweed, or cause the liquid to overflow.
4.Position the boiling tube so that the pondweed is 10 cm away from the light
source. Allow the boiling tube to stand for five minutes. Count the number of
bubbles emerging from the cut end of the stems in one minute. Repeat the count
five times and record your results.
5.Calculate the mean number of bubbles produced per minute. Repeat the
experiment at different distances away from the light source.
* Independent variable – distance from the light source/light intensity.
* Dependent variable – the number of bubbles produced per minute.
* Control variables – concentration of sodium hydrogencarbonate solution,
temperature, using the same piece of Cabomba pondweed each time.
What are the limiting factors of photosynthesis?
Water, temperature, light intensity, carbon dioxide concentratioon, chorophyll levels
What happens when the light intensity and carbon dioxide concentration is increased?
The rate of photosynthesis increases unless another limiting factor is in short supply
What happens when temperature is increased?
The rate of photosynthesis increases until optimum temperature is reached and enzymes are denatured
What are the equations for aerobic respiration?
WORD: glucose + oxygen -> carbon dioxide + water (+ energy)
BALANCED SYMBOL: C6H12O6 + 6O2 è 6CO2 + 6H2O
Where does aerobic respiration take place?
Mitochondria
What is energy used for?
Movement, warmth, and growth & repair
Is respiration endothermic or exothermic?
Exothermic
What is the equation for anaerobic respiration in animals?
glucose -> lactic acid (+ energy)
Why is anaerobic respiration less efficient?
Glucose isnt fully oxidised so less energy is released
What is the equation for anaerobic respiration in plantys and yeast?
glucose -> ethanol + carbon dioxide (+ energy)
Where does anaerobic respiration take place?
Cytoplasm
What happens to lactic acid after exercise?
It is either oxidised to carbon dioxide and water or converted to glucose then glycogen
What is oxygen debt?
The amount of oxygen requireed to remove the lactic acid and replace the body’s oxygen reserves
How does the body respond to exercise?
Increased demand for energy > more cellular respiration > increased oxygen and glucose to cells > increased heart rate > increased blood flow > increased breathing rate > anaerobic respiration will take place if the oxygen supply is insufficient > incomplete oxidation of glucose causes lactic acid build up and oxygen debt
What is metabolism?
The sum of all chemical reactions in the body
What is glucose used for in plants?
-Respiration
-Converted into insoluble starch for storage
-To produce fats and oils for energy storage
-To produce cellulose to strengthen cell walls
-To combine with nitrate ions to produce amino acids for protein synthesis
