Question

For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below. Not all words or phrases will be used; each word or phrase should be used only once. _ pathway th Transporter proteins and ion channels function in membrane transport by providing a _pathway through the membrane for specific polar solutes or inorganic ions. A _2__ is highly selective in the solute it transports, binding the solute at a specific site and changing conformation so as to transport the solute across the membrane. For an uncharged molecule, the direction of passive transport across a membrane is determined solely by its 3_ gradient. On the other hand, for a charged molecule, the_ 4_ must also be considered. The Na+K+ pump is responsible for maintaining high extracellular sodium ion concentrations. This pump carries out a type of transport called_ _5__

WORD BANK

Answer 1

1. Hydrophilic

- cell membranes composed of lipid bilayer and protein molecules are incorporated in it. Protein molecules are hydrophilic in nature and helps in transportation of nutrients.

2. Transporter protein - these proteins are transmembrane molecule and spans the entire cell membrane which creates a passage across a membrane.

3. Concentration - uncharged molecule passes through the transporter protein according to the concentration gradient, where the concentration outside the cell is higher than the inner side of the cell. This is also known as passive diffusion.

4. Facilitated diffusion - its a diffusion which allows diffusion of molecules with the help of protein carrier. It's not a energy driven process. Facilitated diffusion therefore allows polar and charged molecules, such as carbohydrates, amino acids, nucleosides, and ions, to cross the plasma membrane.

5. Active transport - it's a process by which a molecule is transported with the help of a carrier against a concentration gradient and uses energy.