Chapter 11, Problem 11.1CR

What determines whether a cell responds to a hormone such as epinephrine? What determines how a cell responds to such a hormone?

Summary Introduction

To determine: The factor which determines if a cell responds to hormone like epinephrine.

Introduction: The cells signal within themselves and then interpret those signals, which they receive from the environment and various cells. The signals include touch, light or most often the chemicals. The cells communicate in various ways and one of them is the endocrine or hormonal signaling pathway.

Explanation of Solution

The cells present in multicellular organisms communicate usually through the signaling molecules that are targeted for specific cells. The plants and animals use molecules known as hormones for the long distance signaling behavior. This type of signaling is also called the endocrine signaling. Here, there are certain specialized cells that release hormones that travel to various body parts through the circulatory system and recognize the targeted cells. A cell responds to any hormone (epinephrine), only if a receptor protein is present on the cell surface (plasma membrane of the liver cell) or in the cell, where the hormone can bind to it.

Conclusion

A cells responds to any hormone (epinephrine), only if a receptor protein is present on the surface of the cell (plasma membrane of the liver cell) or in the cell where the hormone can bind to it.

Summary Introduction

To determine: The factor which determines the way in which a cell responds to a hormone like epinephrine.

Introduction: Epinephrine hormones are secreted by the medulla of the adrenal glands. The hormones trigger vasoconstriction, and thereby increase the blood pressure.

Explanation of Solution

A cell responds to any hormone (epinephrine), only if a receptor protein is present on the cell surface (plasma membrane of the liver cell) or in the cell, where the hormone can bind to it. Further, the response for the hormone binding depends upon the pathway of signaling or the signal transduction pathway (glycogen phosphorylase in cytoplasm) inside the cell. This will lead to the cellular responses that will be specific for any hormone.

Conclusion

The response for the hormone binding depends on the signal transduction pathway (glycogen phosphorylase in cytoplasm).