The rhodopsin pathway in rod cells is used for visual signaling. Describe the steps involved in...

The rhodopsin pathway in rod cells is used for visual signaling. Describe the steps involved in signal transduction in the rhodopsin pathway.

Expert Solution

The rods and cones serve as sensory nerve endings for visual sensation. light falling upon the retina causes photochemical changes which in turn trigger a cascade of biochemical reactions that result in generation of electrical changes. Photochemical changes occurring in the rods and cones are essentially similar but the changes in rod pigment (rhodopsin or visual purple) have been studied in more detail. This whole phenomenon of conversion of light energy into nerve impulse is known as phototransduction.
Photochemical changes
The photochemical changes include:
Rhodopsin bleaching. Rhodopsin refers to the visual pigment present in the rods—the receptors for night (scotopic) vision. Its maximum absorption spectrum is around 500 nm. Rhodopsin consists of a colourless protein called opsin coupled with a carotenoid called retinine (Vitamin A aldehyde or 11-cis-retinal). light falling on the rods converts 11-cis-retinal component of rhodopsin into 11-cis-retinal through various stages . The all-trans-retinal so formed is soon separated from the opsin . This process of separation is called photodecomposition and the rhodopsin is said to be bleached by the action of light.

Rhodopsin regeneration. The 11-cis-retinal is regenerated from the alt-trans-retinal separated from the opsin (as described above) and vitamin-A (retinal) supplied from the blood. The 11-cis- retinal then reunites with opsin in the rod outer segment to form the rhodopsin. This whole process is called rhodopsin regeneration . Thus, the bleaching of the rhodopsin occurs under the influence of light, whereas the regeneration process is independent of light, proceeding equally well in light and darkness.

Sydney Mullin answered 1 year ago

Describe the process of rhodopsin signaling in rod cells of the mammalian retina.

Describe how activation or synthesis occurs in the follow steps in the GPCR signaling pathway. GPCR...

Describe how activation or synthesis occurs in the follow steps in the GPCR signaling pathway. GPCR and G protein signal molecule and GPCR protein kinase A and cAMP protein kinase A and other protein kinases adenylyl cyclase and cAMP

Describe the mechanisms that limit signaling by the phosphoinositide pathway.

Describe the pathway of visual information to the cortex and explain the major visual field deficits...

Describe the pathway of visual information to the cortex and explain the major visual field deficits resulting from damage along the primary visual pathway? Use your own words in the explanation and give examples.

trace the steps of a long and indirect signaling pathway from a cell-surface receptor to a...

trace the steps of a long and indirect signaling pathway from a cell-surface receptor to a change in gene expression in the nucleus . compare this pathway with an example of a short and direct pathway from cell-surface to the nucleus.

Order the steps in the visual pathway, starting at the eye. number 1-6. a. Activation of...

Order the steps in the visual pathway, starting at the eye. number 1-6. a. Activation of photoreceptors b. Activation of retinal bipolar cells c. Activation of the optic nerve d. Decussation of some fibers at the optic chiasma e. Termination of ganglion cell axons in the thalamus Optic radiations deliver signal to the Visual Cortex.

1. Describe the steps in the metabolic pathway in which cells oxidize a five-carbon, straight-chain, saturated...

1. Describe the steps in the metabolic pathway in which cells oxidize a five-carbon, straight-chain, saturated fatty acid (valerate; 5:0) to the fragments that enter the citric acid cycle. Show the structures of intermediates and products, and indicate where any cofactor(s) participate(s).

Biochemical Signaling i. Write out by hand the steps of the signal transduction pathway starting from...

Biochemical Signaling i. Write out by hand the steps of the signal transduction pathway starting from binding of insulin to its receptor on a liver cell, leading to inhibition of glycogenolysis in that tissue. Include all steps in detail and hand write out this process. Look for hints as to the amount of detail on the Note Outlines with additional notes associated with Module 8. This also requires some review of module 5 on glycogen metabolism. Also remember insulin my...

Mutations to proteins directly involved in the G-protein couple receptor could render the signaling pathway either...

Mutations to proteins directly involved in the G-protein couple receptor could render the signaling pathway either constitutively active or inactive. Explain in which protein(s) can result in constitutively active signaling pathway and which one will result in inactive signaling by mutations.

describe the steps involved in PCR DNA amplification?

Question