Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
Know
remaining cards
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards
share
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

photochem/electics

vision 1

QuestionAnswer
what is responsible for conversion of 11-cis retinal to all trans retinal in the visual pigment rhodopsin? light. as a result: all trans retinal can no longer fit into the binding site on the opsin
formed in 1 msec as a consequence of opsin undergoing conformational changes in response to light metarhodopsin II (activated rhodopsin)
the critical link between the series of photoreceptor reactions and the electrical response is: metarhodopsin II
true or false: the all trans retinal is degraded at the end of the light induced chemical reaction false: it is converted back to the cis retinal form. pigment epithelium is responsible for this.
the dark current refers to: a high sodium conductance( there is depolarization in the dark and membrane potential is close to Na+)
in the rods, if membrane potential is moving closer to K+ equillib potential, the dark current is increased or decreased? dark current is decreased, meaning the rod receptor is hyperpolarized
first step of mechanism of Metarhodopsin II: 1 metarhodopsin activates hundreds of G-proteins called transducin
second step of mechanism of Metarhodopsin II: each transducin molecule stimulates a phosphodiesterase molecule
third step of mechanism of Metarhodopsin II: each phosphodiesterase molecule hydrolyzes 10^3 cGMP (to GMP). without the cGMP Na+ channels close:dark current is reduced
what happens to the photoreceptor potential in response to more light? more hyperpolarization. the response is graded. more light=more hyperpolarized
when the photoreceptor hyperpolarizes what happens with glutamate(neurotransmitter)? less glutamate released from photoreceptor
response of the ganglion cell to excitatory neurotransmitter: increased action potential activity
Created by: nsubact