Description : Thyroid hormones are present in blood (A) In free form (B) In association with thyroxine binding globulin (TBG) (C) In association with thyroxine binding prealbumin (TBPA) (D) Mainly in association with TBG, partly in free form and sometimes in association with TBPA also
Last Answer : Answer : D
Description : All the following statements about TSH are true except (A) It is a tropic hormone (B) It acts on para-follicular cells of thyroid glands (C) Its receptors are membrane-bound (D) Its second messenger is cyclic AMP
Last Answer : Answer : B
Description : The only correct statement about hormone receptors is (A) Receptors for protein hormones are present in cytosol (B) Receptors for steroid hormones are membrane bound (C) Hormone-receptor binding is irreversible (D) Receptors can undergo down regulation and up regulatoin
Description : Which statement is NOT true about non-steroid (peptide) hormones? A) They are derived from peptides, proteins, polypeptides, and derivatives of amino acids. B) They bind to receptors on the cell surface. ... They create an enzyme cascade effect. E) They enter the cell in order to have an effect.
Last Answer : E) They enter the cell in order to have an effect.
Description : Hormone receptors possess all the following properties except (A) All of them are proteins (B) They possess a recognition domain (C) They bind hormones with a high degree of specificity (D) Number of receptors in a target cell is constant
Description : Proteins that are secreted by cells are generally a. not synthesized on membrane-bound ribosomes b. initially synthesized with a signal peptide or leader sequence at their C terminal c. found in ... endocytosis e. secreted in a form that is larger than the form present in the endoplasmic reticulum
Last Answer : found in vesicles and secretory granules
Description : Hormone receptors that stimulate cAMP production (A) are part of a complex of two proteins that transform the external signal into internal cAMP production (B) are proteins distinct and separate from those ... binding of the hormone (D) are not very specific and bind a number of different hormones
Description : Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of ... protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor
Last Answer : Answer: a, d Although most hormone and other messenger receptors are extracellular, intracellular receptors have been identified. The hormone messengers involved for these receptors are primarily ... DNA-binding domain of the receptor. Activation involves the dissociation of the inhibitor protein
Description : All the following statements about ACTH are true except (A) It is a tropic hormone (B) Its target cells are located in adrenal cortex (C) Its receptors are located in the cell membrane (D) Its second messenger is inositol triphosphate
Description : Second messengers a. are substances that interact with first messengers inside cells b. are substances that bind to first messengers in the cell membrane c. are hormones secreted by cells ... the intracellular responses to many different hormonesand neurotransmitters e. are not formed in the brain
Last Answer : mediate the intracellular responses to many different hormonesand neurotransmitters
Description : SRP receptors involved in protein export are present on (A) Ribosomes (B) Endoplasmic reticulum (C) Golgi appartus (D) Cell membrane
Description : Which of the following statement(s) is/are true concerning water movement across cell membranes? a. Water moves only actively through cell membrane transport proteins b. For most cells of ... cells such as the glomerulus of the kidney actively transport water to maintain hydrostatic pressure
Last Answer : Answer: b, c The energetics of water transport across cell membranes is simplified by the fact that water moves only passively due to gradients of hydrostatic pressure or water ... water is distributed at equilibrium. Water distribution is determined entirely by solute to solute distribution
Description : A high surface area to volume ratio in cells is important because it (a) Enables efficient transfer of wastes, nutrients and gases across the cell membrane (b) Prevents overproduction of cell ... self and non-self (d) Provides for better structural support to cope with external physical pressure
Last Answer : Ans:(a)
Description : All the following statements about hormones are true except (A) All of them require specific carriers in plasma (B) All of them require specific receptors in target cells (C) Some of them are subject to feedback regulation (D) Some of them increase the transcription of certain genes
Last Answer : Answer : A
Description : With regard to membrane receptors for hormones: a. they are often glycoproteins b. they are important for hormones made up of steroid c. those for insulin exhibit an intrinsic protein kinase activity d. glucagon uses calcium as a second messenger
Last Answer : they are often glycoproteins
Description : G-proteins act as (A) Hormone carriers (B) Hormone receptors (C) Second messengers (D) Signal transducers
Description : Which one of the following pairs of chemical substances, is correctly categorised? (a) Calcitonin and thymosin - Thyroid hormones (b) Pepsin and prolactin - Two digestive enzymes secreted in ... and myosin - Complex proteins in striated muscles (d) Secretin and rhodopsin - Polypeptide hormones
Last Answer : (c) Troponin and myosin - Complex proteins in striated muscles
Description : Which of the following statement(s) is/are true concerning cell membrane receptors? a. The largest family of cell surface receptors are the G-protein-linked receptors b. Activities of the ... through the use adenylate cyclase d. Tyrosine kinase receptors are considered G-protein-linked receptors
Last Answer : Answer: a, c All water-soluble regulatory molecules bind to the cell surface receptor proteins. Binding of the appropriate ligand evokes an intracellular signal which usually regulates ... are adenylate cyclase, which converts ATP to cAMP, and the polyphosphoinositide-specific phospholipase C
Description : MHC Class III proteins include (A) Immunoglobulins (B) Components of complement system (C) T cells receptors (D) CD4 and CD8 proteins
Description : What is correct to say about the hormone action in humans? (a) Glucagon is secreted by β-cells of islets of Langerhans and stimulates glycogenolysis. (b) Secretion of thymosins is stimulated ... receptors on ovarian cell membrane. (d) FSH stimulates the secretion of estrogen and progesterone.
Last Answer : (c) In females, FSH first binds with specific receptors on ovarian cell membrane.
Description : What is correct to say about the hormone action in humans ? (1) FSH stimulates the secretion of estrogen and progesterone (2) Glucagon is secreted by -cells of Islets of Langerhans and ... stimulated with aging (4) If females, FSH first binds with specific receptors on ovarian cell membrane
Last Answer : (4) If females, FSH first binds with specific receptors on ovarian cell membrane
Description : β-Subunits of insulin receptor are present (A) Outside the cell membrane (B) In the cell membrane (C) Across the cell membrane (D) In the cytosol
Last Answer : Answer : C
Description : α-Subunits of insulin receptor are present (A) Outside the cell membrane (B) In the cell membrane (C) Across the cell membrane (D) In the cytosol
Description : The following are true about the thyroid hormone a. iodide ions enter the follicle cells by passive diffusion b .T4 and T3 bind to the receptors in nuclei c. thyroxine, once ... thyroglobulin until released d. a greater proportion of tri-iodothyronine is formed when iodine is deficient
Last Answer : T4 and T3 bind to the receptors in nuclei
Description : Binding of acetylcholine to its receptors increases the permeability of cell membrane to (A) Ca++ (B) Na+ (C) K+ (D) Na+ and K+
Description : Binding of gamma-aminobutyric acid to its receptors in brain increases the permeability of cell membrane to (A) Cl– (B) Na+ (C) K+ (D) Ca++
Description : G-proteins: a. are activated by the binding of an extracellular ligand to a membrane receptor b. can be mutated in tumour cells c. mediate the action of glucocorticoid hormone d. they are inactivated by cholera toxins
Last Answer : are activated by the binding of an extracellular ligand to a membrane receptor
Description : Which one of the following pairs of hormones are the examples of those that can easily pass through the cell membrane of the target cell and bind to a receptor inside it (mostly in the nucleus)? (a) Insulin, glucagon (b) Thyroxine, insulin (c) Somatostatin, oxytocin (d) Cortisol, testosterone
Last Answer : (d) Cortisol, testosterone
Description : 81. Which one of the following pairs of hormones are the examples of those that can easily pass through the cell membrane of the target cell and bind to a receptor inside it (mostly in the nucleus) (1) Cortisol, testosterone (2) Insulin, glucagon (3) Thyroxin, Insulin (4) Somatostatin, oxytocin
Last Answer : Cortisol, testosterone
Description : Select the correct statement from the following regarding cell membrane. (a) Na+ and K+ ions move across cell membrane by passive transport. (b) Proteins make up 60 to 70% of the cell ... towards the inner part. (d) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson
Last Answer : (d) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson.
Description : Select the correct statement from the following regarding cell membrane (1) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson (2) Na+ and K+ ions move across cell membrane by ... of the cell membrane (4) Lipids are arranged in a bilayer with polar heads towards the inner part
Last Answer : (1) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson
Description : Which of the following is NOT true about hormones? A) Hormones are secreted into the bloodstream. B) Hormones are released from exocrine glands. C) Hormones may be classified as peptides or steroids. ... a target organ. E) Cells that react to a hormone have specific receptors for that hormone.
Last Answer : B) Hormones are released from exocrine glands.
Description : All the following statements about steroid hormones are true except (A) They are hydrophobic (B) They require carriers to transport them in circulation (C) Their receptors are intracellular (D) They require cyclic AMP as second messenger
Description : The gonadotrophic hormones are secreted by (a) anterior lobe of pituitary (b) interstitial cells of testes (c) adrenal cortex (d) posterior part of thyroid.
Last Answer : (a) anterior lobe of pituitary
Description : Which hormone causes acromegaly if present in abnormally high concentrations in an adult? A) growth hormone B) antidiuretic hormone C) gonadotropic hormones D) thyroid-stimulating hormone E) adrenocorticotropic hormone
Last Answer : A) growth hormone
Description : Which of the following is NOT correct about hormones? A) Hormones are generally found across the animal kingdom. B) Hormones may be used at a distance from where the hormone is made. C) ... target cell. E) Hormones are directed to the target organ and avoid contact with non-target cells.
Last Answer : E) Hormones are directed to the target organ and avoid contact with non-target cells.
Description : Insulin like growth hormones are produced by (A) Hypophysis (B) Liver (C) Pancreas (D) Thyroid
Description : Protein bound iodine is _________ bound to protein. (A) Iodine (B) Thyroid hormones (C) Thyroxine (D) Tri iodo thyronine
Description : Secretion of thyroid hormones is regulated by (A) Hypothalamus (B) Anterior pituitary (C) Feedback regulation (D) All of these 220 MCQs IN BIOCHEMISTRY
Description : An enzyme required for the synthesis of thyroid hormones is (A) Iodinase (B) Deiodinase (C) Thyroperoxidase (D) Thyroxine synthetase
Description : Thyroid hormones are synthesized by the iodination of the amino acid: (A) Glycine (B) Phenylalanine (C) Alanine (D) Tyrosine
Description : Excess secretion of thyroid hormones causes (A) Hyperthyroidism (B) Myxoedema (C) Cretinism (D) Cushing syndrome
Description : DOPA is an intermediate in the synthesis of (A) Thyroid hormones (B) Catecholamines (C) Melanin (D) Catecholamines and melanin
Description : All the following statements about phenylketonuria are correct except (A) Phenylalanine cannot be converted into tyrosine (B) Urinary excretion of phenylpyruvate and phenyllactate is increased (C) It ... diet (D) It leads to decreased synthesis of thyroid hormones, catecholamines and melanin
Description : Tryptophan could be considered as precursor of (A) Melanotonin (B) Thyroid hormones (C) Melanin (D) Epinephrine
Description : Which statement is NOT true about steroid hormones? A) They include hormones such as estrogen. B) They do not bind to cell surface receptors. C) The hormone-receptor complex can enter the ... complex can bind to chromatin. E) Steroid hormones act faster than non-steroid (peptide) hormones.
Last Answer : E) Steroid hormones act faster than non-steroid (peptide) hormones.
Description : Which of the following receptors are specifically responsible for maintenance of balance of body and posture? (a) Basilar membrane and otoliths (b) Hair cells and organ of corti (c) Tectorial membrane and macula (d) Crista ampullaris and macula
Last Answer : (d) Crista ampullaris and macula
Description : Virus infected cells produce a set of cytokine proteins called _____ that "alert" surrounding cells to the viral threat. a. Interleukin-1 (IL-1) b. Interferon. c. Toll Like Receptors (TLR) d. Acute Phase Proteins
Last Answer : b. Interferon.
Description : Insulin increases the permeability of glucose across the plasma membrane of muscle cells by (A) Acting on adenylate cycle (B) By loosening the integrity of the membrane (C) Through Ca2 ... membrane cruting the hexose carries of intracellular organelles and making them fuse with the plasma membrane
Description : All the following statements about protooncogenes are true except (A) They are present in human beings (B) They are present in healthy cells (C) Proteins encoded by them are essential (D) They are expressed only when a healthy cell has been transformed into a cancer cell