Question

13. Describe the sodium-potassium pump, including all players involved, and what the function is 16. Name 3 components that contribute to the structure of the plasma membrane 17. Draw and label the reaction of the formation of a peptide bond with two generic amino acids

Answer 1

Answer 13: The sodium potassium pump is transport proteins found on cell membrane which helps in nerve cell signaling. It creates a gradient between sodium and potassium ions. It maintains the resting potential of cells by keeping low concentrations of sodium ions and high concentration of potassium ions inside the cells this it does by pumping sodium out of the cell and by pumping potassium inside the cell which is powered by ATP. In one cycle it pumps three sodium ions outside the cell and two potassium ions inside the cell thereby making interior of cell more negative as compared to exterior of cell hence it helps in maintaining resting potential of cell.

Answer 16: Plasma membrane protects the cell from surrounding and is permeable to ions and organic molecules and therefore it regulates their movement in and out of cells. Plasma membrane is made up of three main components i.e lipid (phospholipid and cholesterol), proteins and carbohydrates. Phospholipids are arranged in bilayers with proteins embedded in it. These proteins acts as channels through which molecules moves inside or outside of cell. Carbohydrates are bound to proteins by forming glycoproteins or they are bound to lipids by forming glycolipids. Phospholipids have one head and two tails. Head is polar and hydrophilic in nature whereas tails are nonpolar and hydrophobic in nature. Head points outwards and tail points inwards to the middle.