The proteins PER and TIM,originally discovered in insect but now found in mammals also,influence circadian rhythms by ____.
A)building up during the day and declining during sleep
B)being transformed into melatonin
C)stimulating and inhibiting (respectively) the release of acetylcholine in the cerebral cortex
D)providing negative feedback from the muscles to the neurons that innervate them

Question

The proteins PER and TIM,originally discovered in insect but now found in mammals also,influence circadian rhythms by ____.​
A)building up during the day and declining during sleep
B)​being transformed into melatonin
C)​stimulating and inhibiting (respectively) the release of acetylcholine in the cerebral cortex
D)providing negative feedback from the muscles to the neurons that innervate them

Quizplus · Accepted Answer

The proteins PER and TIM build up during the day and decline during sleep, which influences circadian rhythms. This is due to the negative feedback loop they create with other proteins in the body, such as CLOCK and BMAL1, which control the expression of genes involved in circadian rhythms. As levels of PER and TIM increase, they inhibit their own expression, leading to a decrease in their levels over time. This cycle is important in regulating sleep-wake cycles and other physiological processes controlled by circadian rhythms.

The Proteins PER and TIM,originally Discovered in Insect but Now