DP Chemistry (last assessment 2024)

Question 20N.3.hl.TZ0.10b(i)

Date	November 2020	Marks available	[Maximum mark: 3]	Reference code	20N.3.hl.TZ0.10b(i)
Level	hl	Paper	3	Time zone	TZ0
Command term	Determine	Question number	b(i)	Adapted from	N/A

b(i).

[Maximum mark: 3]

20N.3.hl.TZ0.10b(i)

The kinetics of an enzyme-catalysed reaction are studied in the absence and presence of an inhibitor. The graph represents the initial rate as a function of substrate concentration.

(b(i))

Determine the value of $V_{\max}$ and $K_{m}$ in the absence and presence of the inhibitor.

[3]

Markscheme

✔✔✔

Award [3] for four values correct.
Award [2] for three values correct.
Award [1] for two values correct.
Ignore units.
Accept $\pm 0.1$ for $K_{m}$ and $V_{m a x}$ . No ECF applied.

Examiners report

The stronger candidates scored all three marks here for the four correct values. Most scored at least one mark for the V_max values in the absence and presence of the inhibitor. The Km values sometimes were outside the permitted ±0.1 range.

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Options » B: Biochemistry » B.7 Proteins and enzymes (HL only)

Options » B: Biochemistry

Question 20N.3.hl.TZ0.10b(i)

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