Question

#3

2. Explain the synthesis of lipids at the ER membrane and how transmembrane proteins are inserted. 3. Compare and contrast types of membrane transport including transport proteins.

Answer 1

Question

3. Plasma membrane is a selectively permeable membrane and it allow only limited substance to pass through freely but other substance require energy or carrier molecule to get transported. The different type of transport are:

I. Simple diffusion:

II. Fasciliated diffusion

III. Primary active transport

IV. Secondary active transport

Differences among various type of membrane transport are:

	Simple diffusion	Fasciliated diffusion	Primary active transport	Secondary active transport
Movement of molecules	From higher concentration to lower concentration	From high concentration to lower concentration	From lower concentration to higher concentration	From lower to higher concentration
Require energy	No	No	Yes	Yes
Require transport proteins	No	Yes	Yes	Yes
Require carrier protein	No	Yes	Yes	Yes

There are mainly two type of transport protein. First is carrier protein and second is channel protein.

I. The channel protein mainly transport ions against the electrochemical gradient whereas carrier transport molecules.

II. The position of channel protein is fixed but confirmation of carrier protein change in plasma membrane.

III. Channel protein have high transporation rates as compare to cartier protein.