Gce Model Questions Vol1 2020 Biology Question 50

Practice objective / multiple choice question 50 from the 2020 Gce Model Questions Vol1 Biology examination.

Gce Model Questions Vol1 2020 Biology Objective / Multiple Choice Medium Difficulty
Question 50 GCE_MODEL_QUESTIONS_VOL1 • 2020 • BIOLOGY • objective

Glucose moves across a cell membrane by passive diffusion. The membrane permeability coefficient for glucose is \(P = 2 \times 10^{-5}\ \text{cm s}^{-1}\). The external glucose concentration is \(5\ \text{mM}\) and the internal concentration is \(1\ \text{mM}\). The effective surface area of the membrane is \(A = 1.5 \times 10^{-4}\ \text{cm}^2\). Using Fick's law \(J = P \; A \; (C_{\text{out}} - C_{\text{in}})\), calculate the rate of glucose entry in moles per second. If an active transport system could increase the uptake three‑fold and each glucose molecule requires one ATP, estimate the number of ATP molecules hydrolysed per second by the active system.

Answer Options

A. Passive diffusion flux = 9.0 × 10⁻¹⁵ mol s⁻¹; three‑fold active uptake requires ≈1.8 × 10¹⁰ ATP molecules per second.
B. Passive diffusion flux = 2.4 × 10⁻¹⁴ mol s⁻¹; three‑fold active uptake requires ≈4.4 × 10¹⁰ ATP molecules per second.
C. Passive diffusion flux = 1.5 × 10⁻¹⁴ mol s⁻¹; three‑fold active uptake requires ≈3.0 × 10¹⁰ ATP molecules per second.
Correct Answer D. Passive diffusion flux = 1.2 × 10⁻¹⁴ mol s⁻¹; three‑fold active uptake requires ≈2.2 × 10¹⁰ ATP molecules per second.
Correct Answer
D
Correct Option:
Passive diffusion flux = 1.2 × 10⁻¹⁴ mol s⁻¹; three‑fold active uptake requires ≈2.2 × 10¹⁰ ATP molecules per second.

About This Question

This is Gce Model Questions Vol1 2020 Biology Question 50. It is one of the objective questions from the 2020 Gce Model Questions Vol1 Biology examination.

Difficulty level: Medium .

View More Gce Model Questions Vol1 2020 Biology Questions More Gce Model Questions Vol1 Practice Questions Back to Questions

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Chat with Support