Proteins that help move certain substances such as water and sugars across the membrane are called?

Question

transport proteins.

active proteins.

passive proteins.

none of the above.

Answer 1

Transport proteins.

Answer 2

Water molecules normally move through the phospholipid bilayer by simple diffusion. However, [channel protein] also known as carrier proteins called aquaporins in plasma membrane increase the rate of diffusion.

For sugar, its also aided by carrier protein.

Answer 3

Sugars are transported across the membrane by (surprise, surprise!) transport proteins. =p Depending on the type of protein and their function, it could be either active or passive. The active form requires energy (ATP) to function and transports sugars from areas of low sugar concentration to areas of high sugar concentration (against the concentration gradient).

Water usually worms its way across the phospholipid bilayer since it is small enough to pass in the space in between the phospholipids. However, sometimes channels called aquaporins are used in certain cells (like those in the kidney tubules) to allow water to move across the cell membrane more rapidly and easily. These are technically transport proteins that are passive, meaning that no energy is required to power the channels.