Types of Hormones - MCAT Biological and Biochemical Foundations of Living Systems
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ACTH is this type of hormone .
I. eicosanoid
II. steroid
III. polypeptide
IV. paracrine
V. None of these is a correct description
ACTH is this type of hormone .
I. eicosanoid
II. steroid
III. polypeptide
IV. paracrine
V. None of these is a correct description
Tap to reveal answer
There are many types of hormones, including all of the categories listed.
Gaseous? The dissolved gas, NO, is now known to be an important second messenger. Paracrine hormones are those that act on cells in close proximity to the secreting cell. ACTH is a polypeptide hormone secreted by the pituitary and conveyed by the bloodstream to the adrenal gland a meter away, so it is clearly not paracrine. ACTH causes the secretion of steroid hormones, but it is not a steroid.
There are many types of hormones, including all of the categories listed.
Gaseous? The dissolved gas, NO, is now known to be an important second messenger. Paracrine hormones are those that act on cells in close proximity to the secreting cell. ACTH is a polypeptide hormone secreted by the pituitary and conveyed by the bloodstream to the adrenal gland a meter away, so it is clearly not paracrine. ACTH causes the secretion of steroid hormones, but it is not a steroid.
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Which of the following is a true statement concerning thyroid hormone?
Which of the following is a true statement concerning thyroid hormone?
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Thyroid hormone is one the few hormones that are derived from a single amino acid, in this case tyrosine. Amino acids (and subsequently their derivatives) are mostly hydrophilic, and are unable to pass through the cell membrane. They must bind to surface receptors in order to initiate their effects on the cell.
Thyroid hormone is one the few hormones that are derived from a single amino acid, in this case tyrosine. Amino acids (and subsequently their derivatives) are mostly hydrophilic, and are unable to pass through the cell membrane. They must bind to surface receptors in order to initiate their effects on the cell.
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Which of the following are NOT transmembrane receptors?
Which of the following are NOT transmembrane receptors?
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Transmembrane receptors are only needed for molecules that CANNOT pass through the cell membrane. Growth hormone, insulin, calcitriol, and secretin are examples of molecules that cannot pass the cell membrane. Their respective receptors are transmembrane receptors. Cortisol, on the other hand, is a cholesterol derivative and can pass through the cell membrane due to its hydrophobic elements. Therefore cortisol receptors are not transmembrane receptors.
Transmembrane receptors are only needed for molecules that CANNOT pass through the cell membrane. Growth hormone, insulin, calcitriol, and secretin are examples of molecules that cannot pass the cell membrane. Their respective receptors are transmembrane receptors. Cortisol, on the other hand, is a cholesterol derivative and can pass through the cell membrane due to its hydrophobic elements. Therefore cortisol receptors are not transmembrane receptors.
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Which of the following is NOT a characteristic of steroid hormones?
Which of the following is NOT a characteristic of steroid hormones?
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Steroid hormones are hydrophobic molecules, synthesized by smooth endoplasmic reticulum. As they are hydrophobic, they require a hydrophilic carrier protein to transport them through the bloodstream. Steroid hormones are generally derived from cholesterol, not amino acids.
Steroid hormones are hydrophobic molecules, synthesized by smooth endoplasmic reticulum. As they are hydrophobic, they require a hydrophilic carrier protein to transport them through the bloodstream. Steroid hormones are generally derived from cholesterol, not amino acids.
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Which of the following hormones most likely functions through cell surface receptors?
Which of the following hormones most likely functions through cell surface receptors?
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Understanding the difference between peptide hormones and glucocorticoids is important in answering this question. Peptide hormones function through cell surface receptors, and usually subsequent G-protein regulated signal amplification. Glucocorticoid hormones generally function by modifying gene expression directly in the nucleus. Generally, peptide hormones end with the suffix -in, while glucocorticoids end with -one or -en. Using this information we see that renin would be a peptide hormone and would therefore function through cell surface receptors.
Understanding the difference between peptide hormones and glucocorticoids is important in answering this question. Peptide hormones function through cell surface receptors, and usually subsequent G-protein regulated signal amplification. Glucocorticoid hormones generally function by modifying gene expression directly in the nucleus. Generally, peptide hormones end with the suffix -in, while glucocorticoids end with -one or -en. Using this information we see that renin would be a peptide hormone and would therefore function through cell surface receptors.
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Which of the following hormones does NOT use a secondary messanger system to perform its function?
Which of the following hormones does NOT use a secondary messanger system to perform its function?
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Peptide hormones rely on a secondary messager system, such as cyclic AMP, to perform their functions on target cells/organs. Of the available answer choices, insulin, calcitonin, and parathyroid hormone (PTH) are peptide hormones, and are therefore incorrect.
Steroid hormones have intracellular receptors and can enter cells directly to cause changes in transcription rates, which result in their effects. Estrogen is a steroid hormone, and thus does NOT use a secondary messanger system.
Peptide hormones rely on a secondary messager system, such as cyclic AMP, to perform their functions on target cells/organs. Of the available answer choices, insulin, calcitonin, and parathyroid hormone (PTH) are peptide hormones, and are therefore incorrect.
Steroid hormones have intracellular receptors and can enter cells directly to cause changes in transcription rates, which result in their effects. Estrogen is a steroid hormone, and thus does NOT use a secondary messanger system.
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Which of the following hormones can be found bound to a cytoplasmic receptor?
Which of the following hormones can be found bound to a cytoplasmic receptor?
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Hormones that bind to cytoplasmic receptors are nonpolar. Nonpolar hormones can pass through the nonpolar phospholipid bilayer of the cell membrane, while polar hormones cannot pass through the cell membrane and must bind to receptors on the surface of the cell. Steroids are nonpolar hormones while peptide hormones are polar hormones. Estrogen is a steroid, and is therefore the correct answer.
Hormones that bind to cytoplasmic receptors are nonpolar. Nonpolar hormones can pass through the nonpolar phospholipid bilayer of the cell membrane, while polar hormones cannot pass through the cell membrane and must bind to receptors on the surface of the cell. Steroids are nonpolar hormones while peptide hormones are polar hormones. Estrogen is a steroid, and is therefore the correct answer.
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Which of the following is a direct hormone?
Which of the following is a direct hormone?
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The pneumonic to remember the hormone of the anterior pituitary is "FLAT PEG." Hormones in the word "FLAT" are tropic hormones, meaning that they act upon other endocrine glands as their target organs. Hormones in the word "PEG" are direct hormones, meaning they act directly on non-endocrine organs.
F - Follicle-stimulating hormone
L - Luteinizing hormone
A - Adrenocorticotropic hormone
T - Thyroid-stimulating hormone
P - Prolactin
E - Endorphins
G - Growth hormone
The pneumonic to remember the hormone of the anterior pituitary is "FLAT PEG." Hormones in the word "FLAT" are tropic hormones, meaning that they act upon other endocrine glands as their target organs. Hormones in the word "PEG" are direct hormones, meaning they act directly on non-endocrine organs.
F - Follicle-stimulating hormone
L - Luteinizing hormone
A - Adrenocorticotropic hormone
T - Thyroid-stimulating hormone
P - Prolactin
E - Endorphins
G - Growth hormone
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Which of the following statements is a key difference between a peptide hormone and a steroid hormone?
Which of the following statements is a key difference between a peptide hormone and a steroid hormone?
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All hormones travel through the bloodstream in order to reach their target cells, but nonpolar hormones typically require a carrier protein. A key difference between peptide hormones and steroid hormones is their solubility. Peptide hormones are polar, which makes it difficult for them to pass through cell membranes. As a result, they attach to a receptor on the outside of the membrane. Steroid hormones, on the other hand, are nonpolar and can pass through cell membranes. They enter the nucleus and directly affect the cell at the transcription level.
All hormones travel through the bloodstream in order to reach their target cells, but nonpolar hormones typically require a carrier protein. A key difference between peptide hormones and steroid hormones is their solubility. Peptide hormones are polar, which makes it difficult for them to pass through cell membranes. As a result, they attach to a receptor on the outside of the membrane. Steroid hormones, on the other hand, are nonpolar and can pass through cell membranes. They enter the nucleus and directly affect the cell at the transcription level.
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Which of the following hormones would not require a carrier protein in the bloodstream?
Which of the following hormones would not require a carrier protein in the bloodstream?
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There are three main types of hormones: peptide hormones, steroid hormones, and tyrosine derivatives. Only peptide hormones are soluble in water, and do not require carrier proteins in the bloodstream. Oxytocin is a peptide hormone, so it will not require a carrier protein.
Aldosterone and testosterone are all steroid hormones, and require a carrier protein. Triiodothyronine (T3) is a tyrosine derivative, and also requires a carrier.
There are three main types of hormones: peptide hormones, steroid hormones, and tyrosine derivatives. Only peptide hormones are soluble in water, and do not require carrier proteins in the bloodstream. Oxytocin is a peptide hormone, so it will not require a carrier protein.
Aldosterone and testosterone are all steroid hormones, and require a carrier protein. Triiodothyronine (T3) is a tyrosine derivative, and also requires a carrier.
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Which of the following hormones is not a peptide hormone?
Which of the following hormones is not a peptide hormone?
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It is important to know the three types of hormones: steroid, peptide, and tyrosine-derived hormones. T4, known as tetraiodothyronine, and the catecholamines are tyrosine-derived hormones. Luteinizing hormone, follicle-stimulating hormone, and growth hormone are all peptide hormones. Steroid hormones include testosterone and estrogen.
It is important to know the three types of hormones: steroid, peptide, and tyrosine-derived hormones. T4, known as tetraiodothyronine, and the catecholamines are tyrosine-derived hormones. Luteinizing hormone, follicle-stimulating hormone, and growth hormone are all peptide hormones. Steroid hormones include testosterone and estrogen.
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Which of the following hormones is a steroid hormone?
Which of the following hormones is a steroid hormone?
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It is important to know the three types of hormones: steroid, peptide, and tyrosine-derived hormones. Thyroid-stimulating hormone and the catecholamines (including epinephrine) are tyrosine-derived hormones. Luteinizing hormone, follicle-stimulating hormone, and growth hormone are all peptide hormones. Steroid hormones include testosterone and estrogen.
It is important to know the three types of hormones: steroid, peptide, and tyrosine-derived hormones. Thyroid-stimulating hormone and the catecholamines (including epinephrine) are tyrosine-derived hormones. Luteinizing hormone, follicle-stimulating hormone, and growth hormone are all peptide hormones. Steroid hormones include testosterone and estrogen.
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Which of the following is a peptide hormone?
Which of the following is a peptide hormone?
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It is important to know the three types of hormones: steroid, peptide, and tyrosine-derived hormones. Thyroid-stimulating hormone and the catecholamines (including epinephrine) are tyrosine-derived hormones. Luteinizing hormone, follicle-stimulating hormone, and growth hormone are all peptide hormones. Steroid hormones include testosterone and estrogen.
It is important to know the three types of hormones: steroid, peptide, and tyrosine-derived hormones. Thyroid-stimulating hormone and the catecholamines (including epinephrine) are tyrosine-derived hormones. Luteinizing hormone, follicle-stimulating hormone, and growth hormone are all peptide hormones. Steroid hormones include testosterone and estrogen.
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Hypersensitivity reactions occur when body tissues are affected by an abnormal immune reaction. The result is damage to normal tissues and clinical illness. A peanut allergy is an example of a hypersensitivity reaction, but there are three additional broad classes.
One class involves the abnormal production or deposition of antibodies. Antibodies are B-cell derived molecules that normally adhere to pathogens, rendering them unable to continue an infection. When antibodies are produced against normal tissues, however, disease can result. Figure 1 depicts a schematic structure of an antibody.
Antibodies can be divided into two peptide chains: heavy and light. Heavy chains form the backbone of the antibody, and are attached to light chains via covalent bonding. Each heavy and light chain is then further divided into constant and variable regions. Variable regions exhibit molecular variety, generating a unique chemical identity for each antibody. These unique patterns help guarantee that the body can produce antibodies to recognize many possible molecular patterns on invading pathogens.
In some hypersensitivity reactions, antibodies circulating in the blood can bind to and activate hormone receptors. For example, in Graves disease, antibodies can activate cell surface receptors for thyroid stimulating hormone (TSH) on thyroid tissue and cause excessive secretion of thyroid hormones. Based on this information, TSH most likely:
I. Is a peptide hormone
II. Modifies nuclear gene transcription
III. Is derived from cholesterol
Hypersensitivity reactions occur when body tissues are affected by an abnormal immune reaction. The result is damage to normal tissues and clinical illness. A peanut allergy is an example of a hypersensitivity reaction, but there are three additional broad classes.
One class involves the abnormal production or deposition of antibodies. Antibodies are B-cell derived molecules that normally adhere to pathogens, rendering them unable to continue an infection. When antibodies are produced against normal tissues, however, disease can result. Figure 1 depicts a schematic structure of an antibody.
Antibodies can be divided into two peptide chains: heavy and light. Heavy chains form the backbone of the antibody, and are attached to light chains via covalent bonding. Each heavy and light chain is then further divided into constant and variable regions. Variable regions exhibit molecular variety, generating a unique chemical identity for each antibody. These unique patterns help guarantee that the body can produce antibodies to recognize many possible molecular patterns on invading pathogens.
In some hypersensitivity reactions, antibodies circulating in the blood can bind to and activate hormone receptors. For example, in Graves disease, antibodies can activate cell surface receptors for thyroid stimulating hormone (TSH) on thyroid tissue and cause excessive secretion of thyroid hormones. Based on this information, TSH most likely:
I. Is a peptide hormone
II. Modifies nuclear gene transcription
III. Is derived from cholesterol
Tap to reveal answer
The question specifies that thyroid-stimulating hormone (TSH) binds to cell surface receptors. This is in contrast to steroid hormones, which are derived from cholesterol and bind to intracellular receptors before moving to the nucleus to directly modify gene expression. Remember, steroids are fat soluble and thus have no need for a receptor on the cell surface; they are small and nonpolar, allowing them to cross the membrane freely. In contrast, peptide hormones are not able to traverse the lipid membrane, and thus require a surface receptor.
The question specifies that thyroid-stimulating hormone (TSH) binds to cell surface receptors. This is in contrast to steroid hormones, which are derived from cholesterol and bind to intracellular receptors before moving to the nucleus to directly modify gene expression. Remember, steroids are fat soluble and thus have no need for a receptor on the cell surface; they are small and nonpolar, allowing them to cross the membrane freely. In contrast, peptide hormones are not able to traverse the lipid membrane, and thus require a surface receptor.
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Researchers are studying a newly-discovered hormone that concentrates in the nuclei of exposed cells. Based on this finding, from which of the following molecules could this hormone possibly be synthesized?
Researchers are studying a newly-discovered hormone that concentrates in the nuclei of exposed cells. Based on this finding, from which of the following molecules could this hormone possibly be synthesized?
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One commonality between all steroid hormones is that they are active in the nucleus. Due to their nonpolar design, these hormones can pass through phospholipid membranes. All steroid hormones can be derived from cholesterol. This class of hormones includes testosterone, estrogen, progesterone, and aldosterone.
The other two classes of hormones are peptide hormones and tyrosine derivatives. Peptide hormones are proteins, synthesized from amino acids residues, and are unable to cross the lipid membrane due to their size and polarity. Thyroid-stimulating hormone is a peptide hormone. Tyrosine derivatives are modified from molecules of the amino acid tyrosine, making them polar. Thyroid hormones and epinephrine are derived from tyrosine.
Glucose is not used to synthesize hormones.
One commonality between all steroid hormones is that they are active in the nucleus. Due to their nonpolar design, these hormones can pass through phospholipid membranes. All steroid hormones can be derived from cholesterol. This class of hormones includes testosterone, estrogen, progesterone, and aldosterone.
The other two classes of hormones are peptide hormones and tyrosine derivatives. Peptide hormones are proteins, synthesized from amino acids residues, and are unable to cross the lipid membrane due to their size and polarity. Thyroid-stimulating hormone is a peptide hormone. Tyrosine derivatives are modified from molecules of the amino acid tyrosine, making them polar. Thyroid hormones and epinephrine are derived from tyrosine.
Glucose is not used to synthesize hormones.
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Which answer choice INCORRECTLY pairs a hormone with its physiological consequence?
Which answer choice INCORRECTLY pairs a hormone with its physiological consequence?
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Calcitonin decreases blood calcium level. All other answer choices correctly pair a hormone with its function.
Calcitonin decreases blood calcium level. All other answer choices correctly pair a hormone with its function.
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Both the sympathetic and the parasympathetic nervous systems are essential for homeostasis and for survival. For example, when we are trying to run away from a threat, the sympathetic nervous system is in full effect to allow us to escape from danger. However, when there is no obvious threat, the parasympathetic nervous system tends to be more in control.
There are similarities and differences between the sympathetic and the parasympathetic nervous systems. In preganglionic nerve fibers, both the sympathetic and the parasympathetic nervous system utilize the neurotransmitter acetylcholine. Closer to the target organ, the parasympathetic nervous system remains dependent on acetylcholine whereas norepinephrine and epinephrine are the predominant neurotransmitters utilized by the sympathetic nervous system.
When norepinephrine and epinephrine bind to their receptors, different effects are carried out based on the type of receptor, affinity, and location of the receptor. For example, epinephrine has a higher affinity for the beta-2 receptor. When epinephrine binds to the beta-2 receptor, common effects include vasodilation and bronchodilation. Norepinephrine has a stronger affinity for the alpha-1, alpha-2 and beta-1 receptors. When norepinephrine binds to its receptor, common effects on the body include vasoconstriction (alpha-1), increased heart rate (beta-1) and uterine contraction (alpha-1).
A patient took an unknown drug. A couple of hours later, her blood pressure skyrocketed to 200mmHg. Which of the following is a possible mechanism of the unknown drug.
Both the sympathetic and the parasympathetic nervous systems are essential for homeostasis and for survival. For example, when we are trying to run away from a threat, the sympathetic nervous system is in full effect to allow us to escape from danger. However, when there is no obvious threat, the parasympathetic nervous system tends to be more in control.
There are similarities and differences between the sympathetic and the parasympathetic nervous systems. In preganglionic nerve fibers, both the sympathetic and the parasympathetic nervous system utilize the neurotransmitter acetylcholine. Closer to the target organ, the parasympathetic nervous system remains dependent on acetylcholine whereas norepinephrine and epinephrine are the predominant neurotransmitters utilized by the sympathetic nervous system.
When norepinephrine and epinephrine bind to their receptors, different effects are carried out based on the type of receptor, affinity, and location of the receptor. For example, epinephrine has a higher affinity for the beta-2 receptor. When epinephrine binds to the beta-2 receptor, common effects include vasodilation and bronchodilation. Norepinephrine has a stronger affinity for the alpha-1, alpha-2 and beta-1 receptors. When norepinephrine binds to its receptor, common effects on the body include vasoconstriction (alpha-1), increased heart rate (beta-1) and uterine contraction (alpha-1).
A patient took an unknown drug. A couple of hours later, her blood pressure skyrocketed to 200mmHg. Which of the following is a possible mechanism of the unknown drug.
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Acute high blood pressure is generally due to systemic vasoconstriction. Of the answer choices, only activating the alpha-1 receptor will elicit peripheral vasoconstriction.
Acute high blood pressure is generally due to systemic vasoconstriction. Of the answer choices, only activating the alpha-1 receptor will elicit peripheral vasoconstriction.
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The cellular membrane is a very important structure. The lipid bilayer is both hydrophilic and hydrophobic. The hydrophilic layer faces the extracellular fluid and the cytosol of the cell. The hydrophobic portion of the lipid bilayer stays in between the hydrophobic regions like a sandwich. This bilayer separation allows for communication, protection, and homeostasis.
One of the most utilized signaling transduction pathways is the G protein-coupled receptor pathway. The hydrophobic and hydrophilic properties of the cellular membrane allows for the peptide and other hydrophilic hormones to bind to the receptor on the cellular surface but to not enter the cell. This regulation allows for activation despite the hormone’s short half-life. On the other hand, hydrophobic hormones must have longer half-lives to allow for these ligands to cross the lipid bilayer, travel through the cell’s cytosol and eventually reach the nucleus.
Cholesterol allows the lipid bilayer to maintain its fluidity despite the fluctuation in the body’s temperature due to events such as increasing metabolism. Cholesterol binds to the hydrophobic tails of the lipid bilayer. When the temperature is low, the cholesterol molecules prevent the hydrophobic tails from compacting and solidifying. When the temperature is high, the hydrophobic tails will be excited and will move excessively. This excess movement will bring instability to the bilayer. Cholesterol will prevent excessive movement.
Which of the following molecules can be found inside of a cell?
I. Steroid hormones
II. Phosphoinositol bisphosphate
III. Calmodulin
The cellular membrane is a very important structure. The lipid bilayer is both hydrophilic and hydrophobic. The hydrophilic layer faces the extracellular fluid and the cytosol of the cell. The hydrophobic portion of the lipid bilayer stays in between the hydrophobic regions like a sandwich. This bilayer separation allows for communication, protection, and homeostasis.
One of the most utilized signaling transduction pathways is the G protein-coupled receptor pathway. The hydrophobic and hydrophilic properties of the cellular membrane allows for the peptide and other hydrophilic hormones to bind to the receptor on the cellular surface but to not enter the cell. This regulation allows for activation despite the hormone’s short half-life. On the other hand, hydrophobic hormones must have longer half-lives to allow for these ligands to cross the lipid bilayer, travel through the cell’s cytosol and eventually reach the nucleus.
Cholesterol allows the lipid bilayer to maintain its fluidity despite the fluctuation in the body’s temperature due to events such as increasing metabolism. Cholesterol binds to the hydrophobic tails of the lipid bilayer. When the temperature is low, the cholesterol molecules prevent the hydrophobic tails from compacting and solidifying. When the temperature is high, the hydrophobic tails will be excited and will move excessively. This excess movement will bring instability to the bilayer. Cholesterol will prevent excessive movement.
Which of the following molecules can be found inside of a cell?
I. Steroid hormones
II. Phosphoinositol bisphosphate
III. Calmodulin
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As mentioned from the passage, steroid hormones must pass through the lipid bilayer in order to reach the nucleus. Phosphoinositol bisphosphate and calmodulin are both secondary messengers as part of the G protein-coupled receptor pathway.
As mentioned from the passage, steroid hormones must pass through the lipid bilayer in order to reach the nucleus. Phosphoinositol bisphosphate and calmodulin are both secondary messengers as part of the G protein-coupled receptor pathway.
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ACTH is this type of hormone .
I. eicosanoid
II. steroid
III. polypeptide
IV. paracrine
V. None of these is a correct description
ACTH is this type of hormone .
I. eicosanoid
II. steroid
III. polypeptide
IV. paracrine
V. None of these is a correct description
Tap to reveal answer
There are many types of hormones, including all of the categories listed.
Gaseous? The dissolved gas, NO, is now known to be an important second messenger. Paracrine hormones are those that act on cells in close proximity to the secreting cell. ACTH is a polypeptide hormone secreted by the pituitary and conveyed by the bloodstream to the adrenal gland a meter away, so it is clearly not paracrine. ACTH causes the secretion of steroid hormones, but it is not a steroid.
There are many types of hormones, including all of the categories listed.
Gaseous? The dissolved gas, NO, is now known to be an important second messenger. Paracrine hormones are those that act on cells in close proximity to the secreting cell. ACTH is a polypeptide hormone secreted by the pituitary and conveyed by the bloodstream to the adrenal gland a meter away, so it is clearly not paracrine. ACTH causes the secretion of steroid hormones, but it is not a steroid.
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Which of the following is a true statement concerning thyroid hormone?
Which of the following is a true statement concerning thyroid hormone?
Tap to reveal answer
Thyroid hormone is one the few hormones that are derived from a single amino acid, in this case tyrosine. Amino acids (and subsequently their derivatives) are mostly hydrophilic, and are unable to pass through the cell membrane. They must bind to surface receptors in order to initiate their effects on the cell.
Thyroid hormone is one the few hormones that are derived from a single amino acid, in this case tyrosine. Amino acids (and subsequently their derivatives) are mostly hydrophilic, and are unable to pass through the cell membrane. They must bind to surface receptors in order to initiate their effects on the cell.
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