Question

passive and active process of membrane transport · concept overview physiology interactive
what type of transport protein is the ion channel?
a. pump
b. ligand - gated channel
c. voltage - gated channel
d. leak channel
which of the following terms describes the movement of na+ from the interstitial fluid into the cell?
a. osmosis
b. active transport
c. simple diffusion
d. facilitated diffusion

Explanation:

For the first question, an ion - channel is a type of transport protein that allows ions to pass through the membrane. It is not a pump (which uses energy to move substances against a gradient). Ligand - gated, voltage - gated, and leak channels are types of ion channels. But the question just asks about the general type of transport protein an ion channel is. For the second question, the movement of Na+ from the interstitial fluid into the cell against its concentration gradient requires energy and is an example of active transport. Osmosis is the movement of water, simple diffusion is the movement of non - polar or small molecules down their concentration gradient without a carrier, and facilitated diffusion is the movement of polar or large molecules down their concentration gradient with a carrier but without energy input.

Answer:

1. None of the above (as an ion - channel is a general type of transport protein different from a pump and the other options are subtypes of ion - channels).
2. B. Active transport