Question

Describe the role played by protein pumps during active transport in plants.

Answer 1

Active transport uses energy to pump molecules against a concentration gradient. Active transport is carried out by membrane play a major role in both active as well as passive transport. Pumps are proteins that use energy to carry substances across the cell membrane.

These pumps can transport substances from a low concentration to a high concentration (‘uphill’ transport). E.g.,H⁺ pump,K⁺ pump, Cl- pump, Na+-K pump.The pumps operate with the help of ATP.K⁺-H⁺ exchange pump occurs in guard cells. Na⁺-K⁺ exchange pump operates across many animal membranes. Transport rate reaches a maximum when all the protein transporters or pumps are being used or are saturated.Like enzymes these carrier proteins are very specific in what they carry across the membrane. These proteins are sensitive to inhibitors that react with protein side chains.

Answer 2

In plant cells, active transport occurs against the concentration gradient, i.e., from a region of lower concentration to a region of higher concentration. The process of active transport involves specific protein pumps. The protein pumps are made up of specific proteins called trans-membrane proteins. These pumps first make a complex with the substance to be transported across the membrane, using the energy derived from ATP. The substance finally gets liberated into the cytoplasm as a result of the dissociation of the protein–substance complex.