Question 1

The two systems responsible for regulating the huge number of chemical processes in the human body are the ________ and ________ systems.

Accepted Answer

The nervous system and endocrine system work together to regulate the chemical processes in the human body. The nervous system controls rapid responses through electrical impulses, while the endocrine system regulates longer-term processes through the release of hormones. Together, they help maintain homeostasis in the body.

Question 2

Which statement(s)about hormones are correct?

Accepted Answer

Hormones are secreted by specific tissues and travel through the blood stream to the location of action, which may be far from the site of secretion. This helps hormones to act over long distances and affect multiple target organs. Thus, option E - Both A and C is the correct choice. Option D is incorrect because hormones act over long distances, not short distances.

Question 3

Which type of hormone actually enters the target cell?

Accepted Answer

Steroid hormones are lipid soluble and can pass through the cell membrane to bind to intracellular receptors, ultimately entering the target cell. Amino acid derivatives and peptides are not lipid soluble and bind to receptors on the cell membrane. Enzymes and zymogens are not hormones.

Question 4

When epinephrine interacts with a cell,the step immediately following binding of the messenger with the receptor site is

Accepted Answer

The step immediately following the binding of epinephrine (or any similar messenger) to its receptor is the activation of a G protein in the cell membrane. This is part of the signal transduction pathway that leads to various cellular responses.

Question 5

Hormones are produced in the ________ system.

Accepted Answer

Hormones are produced in the endocrine system, which consists of various glands throughout the body that secrete hormones directly into the bloodstream to regulate bodily functions. The digestive system is responsible for the breakdown and absorption of nutrients, the excretory system eliminates waste products, the nervous system controls body movements and sensations, and the circulatory system transports oxygen and nutrients throughout the body.

Question 6

The molecule or molecules that interacts with a hormone or other biologically active molecule to initiate a cellular response is called

Accepted Answer

A receptor is a molecule or protein that binds to a hormone or other biologically active molecule, allowing it to initiate a cellular response. Receptors are found on target cells, which are the cells that respond to the hormone or molecule. Receptors are specific to particular hormones or molecules and are critical for proper cellular functioning.

Question 7

The organ that controls the endocrine system is the

Accepted Answer

The hypothalamus is the part of the brain that controls the endocrine system by releasing hormones that stimulate or inhibit the release of hormones from the pituitary gland, which in turn controls the activity of other endocrine glands. The ovaries, testes, thyroid gland, and adrenal gland are all endocrine glands that secrete hormones in response to signals from the hypothalamus and/or pituitary gland. However, none of these organs directly control the endocrine system.

Question 8

Which descriptions are true of hormones?
I.produced by the nervous system
II.transported in the blood stream
III.interact with any cell having the appropriate receptor
IV.act within 1 second or less after release
V.effects may last several hours or days

Accepted Answer

Hormones are not produced by the nervous system, but rather by the endocrine glands. They are transported in the bloodstream and can interact with any cell that has the appropriate receptor. Hormonal effects may last several hours or days, but they typically do not act within 1 second or less after release. Therefore, the descriptions that are true of hormones are II, III, and V.

Question 9

The major chemical structures of hormones include

Accepted Answer

The major chemical structures of hormones include steroids, polypeptides, and amino acid derivatives. Polysaccharides and esters are not commonly seen as hormones, and only including molecules containing amine groups would exclude important hormone categories such as steroid hormones. Therefore, option B is the best choice as it covers all major hormone chemistries.

Question 10

Which two types of hormones act by way of second messengers?
I.amino acid derivatives
II.enzymes
III.peptides
IV.steroids
V.zymogens

Accepted Answer

Amino acid derivatives, enzymes, and peptides all act by way of second messengers. Steroids do not require second messengers and zymogens are inactive precursor enzymes that are activated by cleavage, not hormones that act by way of second messengers. Therefore, the best choice is B (amino acid derivatives and peptides).

Question 11

Chemical messengers deliver information by interacting with ________ in or at the target cell.

Accepted Answer

Chemical messengers interact with receptors in or at the target cell to deliver their message. This interaction can trigger a cellular response in the target cell. Antibodies and antigens are involved in the immune response, while hormones and neurotransmitters are types of chemical messengers.

Question 12

The hypothalamus gland communicates with other tissues by ________ and ________.

Accepted Answer

The answer of The hypothalamus gland communicates with other tissues...

Question 13

Hormones regulate biochemical reactions by

Accepted Answer

Hormones generally act by binding to specific receptor proteins, which then initiate a signaling cascade that ultimately leads to changes in gene expression or other cellular processes. However, the hormones themselves typically do not directly participate in biochemical reactions. Instead, they can produce indirect effects on reactions occurring at some distance from the site of hormone production by altering the behavior of cells or tissues within the body. This can lead to changes in the properties or activity of enzymes or other molecules involved in the target reaction.

Question 14

Which of the following hormones must deliver its signal using the "second-messenger" mechanism?

Accepted Answer

Vasopressin, which is a peptide hormone, signals through the second-messenger mechanism. The hormone binds to the vasopressin receptor, which activates a G protein, leading to the production of the second messenger, cyclic AMP (cAMP), which then activates protein kinase A (PKA) to produce the cellular response. Estradiol, testosterone, progesterone, and androsterone are steroid hormones, which directly diffuse into cells and bind to intracellular receptors to produce a response, without the need for second messengers.

Question 15

All of the following types of molecules function as chemical messengers in the body except

Accepted Answer

Neurons, including axons and dendrons, do not function as chemical messengers themselves, but rather they release neurotransmitters which act as chemical messengers between neurons or between neurons and other cells.

Question 16

The function of a receptor is to

Accepted Answer

The function of a receptor is to receive messages and cause chemical changes within the target cell. This is essential for the proper functioning of cells, tissues, and organs in the body. Receptors play a critical role in various physiological and pathological processes and are the targets for many drugs and therapeutics.

Question 17

The receptors on the surfaces of cell membranes are

Accepted Answer

The receptors on the surfaces of cell membranes are usually protein molecules, capable of recognizing specific ligands and initiating signal transduction pathways upon ligand binding. Lipids, carbohydrates, nucleic acids, and steroids are not typically involved in this process.

Question 18

Chemical messengers that are produced by the endocrine system and circulate in the bloodstream are

Accepted Answer

Hormones are chemical messengers produced by the endocrine system and released into the bloodstream to communicate with target cells and tissues throughout the body. Enzymes are proteins that catalyze chemical reactions, antibodies are produced by the immune system to identify and neutralize foreign substances, neurotransmitters are chemical messengers that transmit signals between nerve cells, and neuropeptides are small proteins that act as neurotransmitters or neuromodulators in the nervous system.

Question 19

Which statement about hormones is not correct?

Accepted Answer

Hormones are not always very specific, they can sometimes have multiple effects on different biochemical reactions or target cells.

Question 20

The endocrine system is most often controlled by

Accepted Answer

The pituitary gland is often referred to as the "master gland" because it releases hormones that control the activities of other endocrine glands in the body. The release of these hormones is controlled by regulatory hormones released by the hypothalamus, which stimulate or inhibit the secretion of pituitary hormones. Therefore, the endocrine system is most often controlled by regulatory hormones released by the pituitary gland upon stimulation from the hypothalamus.

Quiz 28: Chemical Messengers: Hormones, neurotransmitters, and Drugs

The two systems responsible for regulating the huge number of chemical processes in the human body are the and systems.

Which statement(s) about hormones are correct?