You have discovered a protein that transports Ca2 + ions up a concentration gradient, from the cytoplasm into the endoplasmic reticulum. No other ions move during this transport. Which type of transport protein does this appear to be?

Primary Active Uniport

Explanation:

Because this protein transport only Ca + into the E. R it is a uniporter membrane protein. The fact that it transport the Ca + ions against the concentration gradient, then it is active transport. The fact that the ATPs for the pumping of Ca + against the electrochemical gradients is obtained from the biochemical activities inside the cells it is called Primary active transport.

Therefore the transport protein in the question is primary Active Uni-port.

Genrally Uniporters are integral proteins of the cell membrane which bind to the molecules or ions, at a particular time, for the channels to open and to move the molecules in one direction only. They can be stimulated, by voltage change, ligands, or induced by stress.

They played significant role in Action potential transmission, influx of calciun into presynaptic neurone at neuromuscular junction, and transmission of sound waves in vestibulocochlear nerves for sound perception.

Channel protein

Explanation:

A channel protein is one of types of membrane transport protein. It is a membrane transport protein that permits or allows the movement of ions, molecules through the membrane.

Channel proteins transport ions and molecules through the membrane passively by the means of facilitated diffusion.

Channel proteins are very specific to the kinds of ions that they transport through the membrane.

Examples of Channel proteins are: Calcium ion channel, Sodium ion channel e. t. c