IB Biology SL C1.1 Enzymes and metabolism questions

Exam-style multiple choice and written questions with full markschemes. Check multiple choice answers straight away, or type, photograph or draw a written answer and get it marked.

Question 1

Multiple choiceEasy1 mark

A cell’s metabolic reactions must occur quickly enough to support its activities. Which role of enzymes provides this benefit?

Show answer and explanation

Answer: D. Enzymes are catalysts that increase the rates of reactions. Faster metabolic reactions can support the activities of the cell.

A: confuses catalysis with increasing the supply of reactants. B: treats enzymes as an energy source rather than catalysts. C: treats enzymes as reactants that are converted into products.

Remember: enzymes increase reaction rates without being used up.

Question 2

Paper 2Hard16 marks

Researchers cultured equal numbers of animal cells with equal supplies of glucose and amino acids, under the same conditions and with oxygen available. For this investigation, enzyme S catalyses condensation reactions that join glucose monomers into glycogen. In a separate test using enzyme S alone, the activity of S was lower when compound X was present.

After 2 hours, mean measurements per culture were:

TreatmentGlucose removed from medium (mg)Glycogen accumulated (mg)Protein accumulated (mg)CO2 released (mg)
Without X5018814
With X506822

CO2 released was recorded as an indicator of respiration.

(a)

Define metabolism and explain why many different enzymes are required in cells.

[3]
(b)

For each reaction, state whether it is anabolic or catabolic.

  1. Amino acids joined by condensation to form a protein
  2. Glucose monomers joined by condensation to form glycogen
  3. Protein hydrolysed into amino acids during digestion
  4. Glucose oxidized during respiration
[4]
(c)

A researcher claims that X affects glycogen formation but has no effect on metabolism elsewhere. Evaluate this claim using the enzyme test and all the measurements in the table. State one limitation of the evidence.

[9]

The best questions are still waiting

Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.