Podcast
Questions and Answers
What is the initial step in the transduction of visual information to the nervous system?
What is the initial step in the transduction of visual information to the nervous system?
- Hydrolysis of cyclic GMP
- Conversion of cis-retinal to trans-retinal (correct)
- Binding of sodium ions to channels
- Activation of a G protein
What is the result of the enzyme phosphodiesterase hydrolyzing cyclic GMP in rods and cones?
What is the result of the enzyme phosphodiesterase hydrolyzing cyclic GMP in rods and cones?
- The visual pigment is activated
- Sodium ion channels close (correct)
- The cell becomes depolarized
- Sodium ion channels open
Why are rods in which the light response is saturated often described as 'bleached'?
Why are rods in which the light response is saturated often described as 'bleached'?
- Due to the permanent damage to the rods
- Due to the change in color of rhodopsin from purple to yellow (correct)
- Due to the decrease in sodium ion channels
- Due to the temporary loss of responsiveness
What is the function of cyclic GMP in rods and cones in the dark?
What is the function of cyclic GMP in rods and cones in the dark?
Why do rods not regain full responsiveness for several minutes after a sudden decrease in light intensity?
Why do rods not regain full responsiveness for several minutes after a sudden decrease in light intensity?
What is the shape difference between trans-retinal and cis-retinal?
What is the shape difference between trans-retinal and cis-retinal?
What is the effect of light on the visual pigment in rods?
What is the effect of light on the visual pigment in rods?
What is the role of the enzyme phosphodiesterase in the signal transduction pathway?
What is the role of the enzyme phosphodiesterase in the signal transduction pathway?
What is the result of the cell becoming hyperpolarized in the rods and cones?
What is the result of the cell becoming hyperpolarized in the rods and cones?
What is the function of the G protein in the signal transduction pathway?
What is the function of the G protein in the signal transduction pathway?
What is the difference between cis-retinal and trans-retinal?
What is the difference between cis-retinal and trans-retinal?
What is the effect of a sudden decrease in light intensity on the rods?
What is the effect of a sudden decrease in light intensity on the rods?
What is the role of sodium ion channels in the rods and cones in the dark?
What is the role of sodium ion channels in the rods and cones in the dark?
What is the result of the signal transduction pathway in bright light?
What is the result of the signal transduction pathway in bright light?
What is the purpose of the enzymes that convert retinal back to its cis form?
What is the purpose of the enzymes that convert retinal back to its cis form?
