Biology Lab, Final Exam Questions with 100% Verified
Answers Latest Update
Question: Why did the catalase function level off when different hydrogen peroxide
concentrations were tested?
Answer:
At some point, all the catalase in solution was catalyzing reactions, so even if the hydrogen
peroxide concentration was increased, the rate of the reaction could not increase any more.
Question: How much slower would hydrogen peroxide likely be decomposed if catalase was
not available in cells?
Answer:
1,000,000 times
Question: At which temperatures did catalase function somewhat, but not optimally?
Answer:
21.5°C
Question: Why did catalase fail to function at 80 °C?
Answer:
The catalase failed to function at 80°C because it had surpassed its optimal functioning
temperature to the point of damaging the enzyme.
Question: Before the catalase concentration was saturated with hydrogen peroxide, why did
the enzyme function vary with substrate concentration?
Answer:
The enzyme function increased before it was saturated with substrate because it hadn't yet
had enough substrate to saturate all the enzymes.
Question: Why did catalase only function in a limited range of pH values?
Answer:
Catalase is an enzyme, which will function best at an optimal pH and temperature. Acidic or
alkaline conditions cause an enzyme to become distorted, after which it will no longer work.
Question: What are the enzyme, substrate, and product in these experiments?
Answer:
The enzyme in this experiment was Catalase, found in the livers of mammals. The substrate
was 3% Hydrogen Peroxide, and the product was oxygen.
, Question: What role does catalase play in the mammalian liver, or any other cell it is found
in?
Answer:
The catalase enzyme breaks down hydrogen peroxide, which is a byproduct of some cell
functions, into oxygen.
Question: How do plants metabolize the sugars they produce by photosynthesis?
Answer:
by cellular respiration
Question: What was the name of the plant you used to study photosynthesis?
Answer:
Elodea
Question: Why did the volume increase in the gas syringe on the Elodia vial?
Answer:
Oxygen was produced through photosynthesis, increasing gas in the syringe.
Question: Why did the volume of gas in the syringe decrease during dark respiration?
Answer:
During periods of darkness, the plant does not conduct photosynthesis, so it does not
produce more oxygen. Cellular respiration processes do continue, using the available
oxygen.
Question:
Answer:
Question: What inputs are required for photosynthesis to produce oxygen and glucose?
Answer:
CO2,Sunlight, and Water (for hydrogen) are required to produce oxygen and glucose.
Question: A student replicates all the variables of the first experiment, except she puts the
plant in a sealed jar without oxygen but with carbon dioxide. How do you think that would
affect her results?
Answer:
The jar would break or the stopper would push out as the plants conduct photosynthesis
and create oxygen.
Answers Latest Update
Question: Why did the catalase function level off when different hydrogen peroxide
concentrations were tested?
Answer:
At some point, all the catalase in solution was catalyzing reactions, so even if the hydrogen
peroxide concentration was increased, the rate of the reaction could not increase any more.
Question: How much slower would hydrogen peroxide likely be decomposed if catalase was
not available in cells?
Answer:
1,000,000 times
Question: At which temperatures did catalase function somewhat, but not optimally?
Answer:
21.5°C
Question: Why did catalase fail to function at 80 °C?
Answer:
The catalase failed to function at 80°C because it had surpassed its optimal functioning
temperature to the point of damaging the enzyme.
Question: Before the catalase concentration was saturated with hydrogen peroxide, why did
the enzyme function vary with substrate concentration?
Answer:
The enzyme function increased before it was saturated with substrate because it hadn't yet
had enough substrate to saturate all the enzymes.
Question: Why did catalase only function in a limited range of pH values?
Answer:
Catalase is an enzyme, which will function best at an optimal pH and temperature. Acidic or
alkaline conditions cause an enzyme to become distorted, after which it will no longer work.
Question: What are the enzyme, substrate, and product in these experiments?
Answer:
The enzyme in this experiment was Catalase, found in the livers of mammals. The substrate
was 3% Hydrogen Peroxide, and the product was oxygen.
, Question: What role does catalase play in the mammalian liver, or any other cell it is found
in?
Answer:
The catalase enzyme breaks down hydrogen peroxide, which is a byproduct of some cell
functions, into oxygen.
Question: How do plants metabolize the sugars they produce by photosynthesis?
Answer:
by cellular respiration
Question: What was the name of the plant you used to study photosynthesis?
Answer:
Elodea
Question: Why did the volume increase in the gas syringe on the Elodia vial?
Answer:
Oxygen was produced through photosynthesis, increasing gas in the syringe.
Question: Why did the volume of gas in the syringe decrease during dark respiration?
Answer:
During periods of darkness, the plant does not conduct photosynthesis, so it does not
produce more oxygen. Cellular respiration processes do continue, using the available
oxygen.
Question:
Answer:
Question: What inputs are required for photosynthesis to produce oxygen and glucose?
Answer:
CO2,Sunlight, and Water (for hydrogen) are required to produce oxygen and glucose.
Question: A student replicates all the variables of the first experiment, except she puts the
plant in a sealed jar without oxygen but with carbon dioxide. How do you think that would
affect her results?
Answer:
The jar would break or the stopper would push out as the plants conduct photosynthesis
and create oxygen.
