Question

1. Explain what happens to the action potential frequency of a cold and a warm receptor as the environmental temperature increases linearly from 20 to 40 degree Celsius and back again?

2. Some hormones bind to carrier proteins and are transported in the blood as complexes. Explain the advantages of such complexes and name one hormone that is transported in this way.

Answer 1

Answer 1:

• With an increase in the temperature, there is a decrease in the amplitude of action potential along with decrement in the duration.
• The phenomenon of cooling decreases depolarization (resting potential) which can raise the frequency of action potential.

Answer 2:

• Endocrine hormones are transported into the blood and are carried by blood and tissues. The highly selective transport proteins which transport endocrine hormones include sex hormone binding globulin (transports estradiol and testosterone) and corticosteroid binding globulin (transports glucocorticoids)
• The carrier proteins are advantageous because they promote the movement of molecules across the cell membrane to a specific target