Unit 3 check

Unit 3 check: Cellular Energetics

10 questions from 5 lessons in Unit 3. Answer each one, and if you miss, follow the link back to where it is taught, then try again. Your score counts first tries.

Question 1 · from 3.1 · Fill the statement

Complete the description of an enzyme.

An enzyme is a that acts as a biological : it speeds up a chemical reaction and is by that reaction.

Question 2 · from 3.2 · Sort it

Each card describes one enzyme sample. Tap a card, then the bin that best describes what happened to that sample's enzyme.

Rate changed, but its structure is unchanged

Structure changed, and activity can return

Structure changed, and activity does not return

Question 3 · from 3.3 · Multiple choice

In a pathway W to X to Y to Z, each step is catalyzed by its own enzyme. A poison stops only the enzyme that converts X to Y. What happens in the cell?

Question 4 · from 3.4 · Match

Match each term to its description.

Setup for question 5

A new organism, a new question. Yeast cells are grown in two sealed flasks with a steady supply of glucose at the same temperature. One flask has oxygen; the other has none. These numbers are a teaching example.

With oxygen: 10 units of glucose used per hour, 2 units of alcohol made
Without oxygen: 60 units of glucose used per hour, 110 units of alcohol made

Question 5 · from 3.5 · Calculate

Without oxygen, the yeast use how many times as much glucose per hour as with oxygen?

Your answer

Question 6 · from 3.1 · Sort it

An enzyme is added to a reaction. Tap each card, then the bin that says what happens to it.

Changes when the enzyme is added

Stays the same when the enzyme is added

Question 7 · from 3.2 · Multiple choice

In a tube with an enzyme and its substrate, product forms quickly at first, then more and more slowly. The temperature and pH stay at the enzyme's optimum throughout. Which explanation is best supported?

Question 8 · from 3.3 · Match

Match each term to its description.

Setup for question 9

A new experiment, a new question. A student shines light on a suspension of algae, then switches the light off. She measures how fast the algae take up CO₂ from the water around them. These numbers are a teaching example.

Light on: 12 units per minute
1 minute after the light goes off: 3 units per minute
3 minutes after the light goes off: 0 units per minute

Question 9 · from 3.4 · Calculate

One minute after the light goes off, the rate of CO₂ uptake is what percentage of the rate with the light on? Give your answer to the nearest whole percent.

Your answer %

Setup for question 10

With oxygen: 10 units of glucose used per hour, 2 units of alcohol made
Without oxygen: 60 units of glucose used per hour, 110 units of alcohol made

Question 10 · from 3.5 · Decide and justify

A student claims the yeast without oxygen use more glucose because fermentation captures more energy from each glucose molecule than aerobic respiration does. Is the claim correct?

Which reasoning supports your decision?

0 of 10 answered.