Question

A biologist conducts an experiment designed to determine whether a particular type of molecule is transported into cells by simple diffusion, facilitated diffusion, or active transport. He collects the following information: 1) The molecule is very small. 2) The molecule is polar. 3) The molecule can accumulate inside cells even when its concentration inside the cell initially is higher than it is outside the cell. 4) Cells use up more energy when the molecule is present in the environment around the cells than when it is not present. The biologist concludes that the molecule moves across cell membranes by facilitated diffusion. Do you agree with his conclusion?

Answer 1

No, the biologist's conclusion is incorrect; the described properties suggest that the molecule is transported across cell membranes by active transport, not facilitated diffusion.

Step-by-step explanation:

The conclusion drawn by the biologist does not appear to be correct based on the information provided. When considering the information given:

• The molecule is polar and small in size.
• It can accumulate inside cells even when its concentration inside the cell is higher than outside, suggesting movement against the concentration gradient.
• More energy is used by cells when the molecule is present, indicating an energy-requiring process.
• These observations are not consistent with facilitated diffusion which is a form of passive transport requiring no energy and occurs down a concentration gradient. Instead, the characteristics described fit active transport, where molecules move against a concentration gradient with the use of energy (ATP).

Answer 2

No, this is not a facilitated diffusion but an Active transport process.

Explanation:

This is an active transport process because -

• The molecules are moving against the concentration gradient from higher concentration to lower concentration.

• It is using up energy.

• The energy is stored in the form of ATP.

• To move across the concentration gradient ATP is needed.

So, we can say that the whole experiment undergoes the Active transport process.