Part of the retina of a young rat was removed and kept in the dark for two hours. This allowed the pigment in the rod cells to recover from bleaching caused by exposure to light. Suggest what happens in the rod cells during this two hours of darkness.

Rhodopsin is the pigment found in rod cells, which consists of cis-retinal and the protein opsin. When the rod cells are kept in darkness, the opsin is uncoupled from the cell surface membrane of the rod cells and the trans-retinal is converted back to cis-retinal. These 2 components join to reform rhodopsin, resulting in a process known as dark adaptation. The permeability of the rod cell to sodium ions increases as the sodium channels become unblocked, decreasing the hyperpolarisation within the cell. This leads to the release of greater quantities of neurotransmitter (glutamate).

PL
Answered by Panos L. Biology tutor

4708 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Explain how an electrochemical gradient is formed in the mitochondria, and how this gradient is used to synthesise ATP.


Effect of substrate concentration on enzyme catalysed reaction


What is eutrophication?


How and why are bacteria used in industry?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences