What is the chemical composition of the rod pigment, rhodopsin, and how does it appear to act in the reception of light?
What will be an ideal response
Rhodopsin is a combination of retinal and opsin. Retinal is chemically related to vitamin A and is synthesized from it. Retinal can form a variety of three-dimensional forms called isomers. The opsin protein combines with the 11-cis retinal to form rhodopsin. The light-triggered changes in retinal cause hyperpolarization of the rods. This happens because the light turns off sodium entry, which then inhibits the release of neurotransmitter, thus turning off electrical signals.
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a. Blood flows through the aorta and the pulmonary trunk. b. The semilunar valves open. c. The ventricles contract. d.The ventricles relax. e. The atrioventricular valves close.
Which buffer system accounts for 75% of all chemical buffering in the body fluids?
A. The bicarbonate system B. The phosphate system C. The ammonium buffer system D. The protein buffer system E. The carbonic acid system
The ________ system regulates blood volume and pressure, stimulates red blood cell formation, and controls fluid, electrolyte, and acid-base balance
A) digestive B) urinary C) circulatory D) respiratory E) muscular
This figure shows an anterior view of the spinal cord and meninges. What structure does number 1 indicate?
A. Anterior root B. Posterior root C. Anterior root ganglion D. Posterior root ganglion E. Gray commissure