Question

Scientists were monitoring the biochemical properties of a proton transporter by comparing the pH inside & outside the cell in the presence or absence of ATP. They noticed that the pH of the solution outside of the cell went down when ATP was added. Explain (a) whether the transporter used active or passive transport, (b) the direction of movement of the proton (H+), and (c) whether the reaction was endergonic or exergonic

Answer 1

1. Active transport: Metabolic energy is used to move ions or molecules against concentration gradient. Active transport results in the accumulation of solute on one side of membrane. Transport ATPase are the ATP powered pumps. Three major types are associated with membranes that couple ATP hydrolysis to the translocation of specific ions across a membrane. P-ATP ase have a simple polypeptide composition and are phosphorylated during catalysis

Ex: H+-ATPase of the plasma membranes of fungi and plants

1. The proton (H+) were move inside to outside of the cell
2. The cell was ATP metabolic energy is used to move ions or molecules , energy-requiring (endergonic) processes. ATP is extremely soluble in water and is relatively stable in solutions between pH 6.8 and 7.4.