Question

Describe the three mechanisms via which the transport of a solute against its free energy gradient can be coupled to a source of energy (identify the source of energy in each case).

Explain the difference between direct (primary) and indirect (secondary) active transport and discuss how these two processes are "connected" to each other in cells. Think about how the effect of Na+/K+ ATPase (Na+/K+ pump) on the intracellular concentration (and electrochemical potential) of Na+ can be used to drive the transport of other solutes against their free energy gradient.

Explain the major similarities and differences between P-type pumps, V-type pumps, F-type pumps, and ABC transporters in terms of:

Type of solute transported

Source of energy for transport

Transport mechanism (is the pump phosphorylated as part of the transport process)

General localization in the cell (obviously, there are exceptions, but in general, where are these different types of pumps located in the cell).

Answer 1

Three mechanism that works for solute to move against its gradiend include:

1.ATPase/ v-type pump that uses ATP as the energy source

2. Secondary active transport that employes coupling with a molecule that has enough energy to move itself across the membrane

3. Facultative transport in which a membrane protein that is an integral protein is used to move the solute across it

Primary active transport	secondary active transport
It uses ATP directly for the transport It plays a direct role in cellular metabolism	it uses ATP indirectly It plays an indirect role in cellular metabolisms

These two processes are connected to each other in the cell as they transport solute against the gradient and the hydrolysis of the ATP makes it efficient and specific in nature