Gce Model Questions Vol1 2023 Biology Question 24

Practice objective / multiple choice question 24 from the 2023 Gce Model Questions Vol1 Biology examination.

Gce Model Questions Vol1 2023 Biology Objective / Multiple Choice Medium Difficulty
Question 24 GCE_MODEL_QUESTIONS_VOL1 • 2023 • BIOLOGY • objective

A cell membrane is \(5\ \text{nm}\) thick and has a permeability coefficient for glucose of \(P = 1.2 \times 10^{-5}\ \text{cm\,s}^{-1}\). The external glucose concentration is \(5\ \text{mM}\) and the internal concentration is \(1\ \text{mM}\). The cell has a total membrane surface area of \(1 \times 10^{-5}\ \text{cm}^{2}\). (i) Calculate the net molar flux of glucose across the membrane (in \(\text{mol\,min}^{-1}\)). (ii) If the cell's metabolic demand for glucose is \(2 \times 10^{-12}\ \text{mol\,min}^{-1}\), does passive diffusion meet this demand?

Answer Options

A. Flux ≈ 1.5×10⁻¹³ mol min⁻¹; this is below the required 2×10⁻¹² mol min⁻¹, so passive diffusion is insufficient.
Correct Answer B. Flux ≈ 2.9×10⁻¹⁴ mol min⁻¹; this is far below the required 2×10⁻¹² mol min⁻¹, so passive diffusion is insufficient.
C. Flux ≈ 2.9×10⁻¹⁴ mol min⁻¹; this exceeds the required 2×10⁻¹² mol min⁻¹, indicating diffusion is more than enough.
D. Flux ≈ 4.0×10⁻¹⁴ mol min⁻¹; this meets the required 2×10⁻¹² mol min⁻¹, so passive diffusion is sufficient.
Correct Answer
B
Correct Option:
Flux ≈ 2.9×10⁻¹⁴ mol min⁻¹; this is far below the required 2×10⁻¹² mol min⁻¹, so passive diffusion is insufficient.

About This Question

This is Gce Model Questions Vol1 2023 Biology Question 24. It is one of the objective questions from the 2023 Gce Model Questions Vol1 Biology examination.

Difficulty level: Medium .

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