Sensory Transduction in the Eye

What is the initial step in the transduction of visual information to the nervous system?

Conversion of cis-retinal to trans-retinal

What is the result of the enzyme phosphodiesterase hydrolyzing cyclic GMP in rods and cones?

Sodium ion channels close

Why are rods in which the light response is saturated often described as 'bleached'?

Due to the change in color of rhodopsin from purple to yellow

What is the function of cyclic GMP in rods and cones in the dark?

It binds to sodium ion channels and keeps them open Signup and view all the answers

Why do rods not regain full responsiveness for several minutes after a sudden decrease in light intensity?

Due to the time required for enzymes to convert retinal back to the cis form Signup and view all the answers

What is the shape difference between trans-retinal and cis-retinal?

Trans-retinal has a different shape than cis-retinal Signup and view all the answers

What is the effect of light on the visual pigment in rods?

It activates the visual pigment Signup and view all the answers

What is the role of the enzyme phosphodiesterase in the signal transduction pathway?

It hydrolyzes cyclic GMP Signup and view all the answers

What is the result of the cell becoming hyperpolarized in the rods and cones?

A decrease in the response to light Signup and view all the answers

What is the function of the G protein in the signal transduction pathway?

It activates the enzyme phosphodiesterase Signup and view all the answers

What is the difference between cis-retinal and trans-retinal?

They differ in their spatial arrangement of atoms Signup and view all the answers

What is the effect of a sudden decrease in light intensity on the rods?

They become less sensitive to light Signup and view all the answers

What is the role of sodium ion channels in the rods and cones in the dark?

They are open Signup and view all the answers

What is the result of the signal transduction pathway in bright light?

The response in the rods becomes saturated Signup and view all the answers

What is the purpose of the enzymes that convert retinal back to its cis form?

To inactivate the visual pigment Signup and view all the answers

Sensory Transduction in the Eye

Questions and Answers