Description : The following are true about parathyroid hormone a. it is an 84 amino acid peptide hormone b. it increases calcium absorption from the gastrointestinal tract c. it acts on a cell surface receptor that increases intracellular cyclic AMP d. all above
Last Answer : all above
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 : 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 : Hormone that binds to intracellular receptor is (A) Adrenocorticotropic hormone (B) Thyroxine (C) Follicle stimulating hormone (D) Glucagon
Last Answer : Answer : B
Description : Receptors perform the following function/functions: A. Ligand recognition B. Signal transduction C. Both ligand recognition and signal transduction D. Disposal of agonists and antagonists
Last Answer : D. Disposal of agonists and antagonists
Description : The following receptor type has 7 helical membrane spanning amino acid segments with 3 extracellular and 3 intracellular loops: A. Tyrosine protein kinase receptor B. Gene expression regulating receptor C. Intrinsic ion channel containing receptor D. G protein coupled receptor
Last Answer : D. G protein coupled receptor
Description : 6.2 Which hormone acts through a cytoplasmic receptor: A. Calcitriol B. Prolactin C. Vasopressin D. None of the abov
Last Answer : A.Calcitol binds to cytoplasmic membrane and enhances the absorption of Calcium by increasing the calcium binding proteins-calbindin-D proteins.
Description : The GABAB receptor: A. Is an intrinsic ion channel containing receptor B. Mediates neuronal depolarization C. Is insensitive to blockade by bicuculline D. Regulates intracellular cAMP
Last Answer : C. Is insensitive to blockade by bicuculline
Description : All of the following subserve as intracellular second messengers in receptor mediated signal transduction except: A. Cyclic AMP B. Inositol trisphosphate C. Diacyl glycerols D. G proteins
Last Answer : D. G proteins
Description : Phosphorylated IRS-1 activates GRB-2 which is (A) G-protein receptor binding protein-2 (B) Growth factor receptor binding protein-2 (C) Growth hormone receptor binding protein-2 (D) Glucocorticoid receptor binding protein-2 226 MCQs IN BIOCHEMISTRY
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
Last Answer : Answer : D
Description : Identify A, B and C in the diagramatic representation of the mechanism of hormone action. B A Response 1 C Physiological Responses Select the correct option from the following. (a) A-Steroid Hormone; B- ... ; C - Second Messenger (d) A-Protein Hormone; B-Cyclic AMP; C-Hormone-receptor Complex
Last Answer : (b) A-Protein Hormone; B-Receptor; C-Cyclic AMP
Description : Which does NOT occur in a cell stimulated by a steroid hormone? A) The steroid hormone enters the cell by crossing the plasma membrane. B) The hormone binds to a receptor molecule in the ... activates certain genes. E) DNA is transcribed, mRNA is translated, and the result is protein synthesis.
Last Answer : C) The second messenger cyclic AMP is stimulated by the hormone-receptor complex. D) The hormone-receptor complex binds the chromatin and activates certain genes.
Description : Which is associated with a steroid hormone? A) cyclic AMP B) the second messenger system C) production of new proteins D) activation of proteins present in an inactive form E) binding of a protein to a surface receptor on the plasma membrane
Last Answer : C) production of new proteins
Description : Select the opioid analgesic which acts primarily through κ (kappa) opioid receptor: A. Pentazocine B. Methadone C. Buprenorphine D. Pethidine
Last Answer : A. Pentazocine
Description : As an antitubercular drug, isoniazid has the following advantages except: A. It is tuberculocidal B. It acts on both extra and intracellular bacilli C. Tubercle bacilli do not develop resistance against it D. It is cheap
Last Answer : C. Tubercle bacilli do not develop resistance against it
Description : An example of protein which acts as a hormone is : (1) nypsin (2) Oxytocin (3) Keratin (4) Casein
Last Answer : (2) Oxytocin Explanation: Hormonal Proteins are messenger proteins which help to coordinate certain bodily activities. Examples include Insulin, Oxytocin, and Somatotropin. Oxytocin stimulates contractions in females during childbirth.
Description : An example of protein which acts as a hormone is : (1) Trypsin (2) Oxytocin (3) Keratin (4) Casein
Last Answer : Oxytocin
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 : Intracellular organelles involved with protein synthesis include: a. Mitochondria b. Endoplasmic reticulum c. Golgi complex d. Lysosomes
Last Answer : Answer: b, c Mitochondria are the major source of energy production in eukaryotic cells. The endoplasmic reticulum is the network of interconnected membranes forming closed vesicles, ... containing acid hydrolytic enzymes that degrade polymers such as proteins, carbohydrates, and nucleic acids
Description : The best understood intracellular messenger is cyclic AMP (cAMP). Which of the following statement(s) concerning this intracellular messenger is/are correct? a. Intracellular cyclic AMP is constantly ... of adenylate cyclase d. cAMP is the only cyclic nucleotide active as an intracellular messenger
Last Answer : Answer: a, b The prototypic intracellular messenger is cAMP. To function as a mediator, the concentration of cAMP must change rapidly. In resting cells, cAMP is continuously being degraded by ... produce cGMP. Intracellular calcium ions also serve as second messengers in a large number of cells
Description : Compared with intracellular fluid, extracellular fluid has, a. a greater osmolarity b. a higher protein concentration c. a lower chloride ion concentration d. a lower hydrogen ion concentration
Last Answer : a lower hydrogen ion concentration
Description : Which of the following structure-function pairs is mismatched? (A) Lysosome-intracellular digestion (B) Golgi body-secretion of cell products (C) Ribosome-protein synthesis (D) Glyoxysome-detoxification
Last Answer : (D) Glyoxysome-detoxification
Description : Apolipoprotien B-100 acts as (A) Enzyme activator (B) Ligand for receptor (C) Both (A) and (B) (D) None of these
Description : Apolipoprotein A-I acts as (A) Enzyme activator (B) Ligand for receptor (C) Both (A) and (B) (D) None of these
Last Answer : Answer : C
Description : The apolipoprotein which acts as ligand for LDL receptor is (A) B-48 (B) B-100 (C) A (D) C
Description : Cell regulation can be thought of as the effector side of cell communication. Most commonly cell regulation occurs by means of extracellular chemical messengers. Which of the following statement(s ... d. Most hormones, local mediators, and neurotransmitters readily cross the cell plasma membrane
Last Answer : Answer: b, c Depending on how the extracellular messenger arrives, cell regulation can be classified as paracrine, endocrine, or neurocrine. In paracrine regulation, a chemical messenger ... , local mediators, and neurotransmitters are water-soluble and cannot readily cross the plasma membrane
Description : Aliskiren acts by (A) inhibiting the conversion of Angiotensin I to II (B) inhibiting the release of rennin (C) inhibiting the binding of Angiotensin II to the receptor (D) inhibiting the action of aldosterone
Last Answer : (B) inhibiting the release of rennin
Description : Features of µ (Mu) opioid receptor include the following except: A. Acts by inhibiting cAMP formation B. Mediates miotic action C. Mediates low ceiling respiratory depression D. Mediates high ceiling supraspinal analgesia
Last Answer : C. Mediates low ceiling respiratory depression
Description : Choose the correct statement(s) about pioglitazone: A. It acts as an agonist on nuclear paroxisome proliferator receptor γ B. It enhances transcription of insulin responsive genes C. It lowers blood sugar in type 2 diabetes mellitus without causing hyperinsulinemia D. All of the above
Last Answer : D. All of the above
Description : Hormone which regulate gene expression or chromosome by interation of hormone receptor complex with the genome are
Last Answer : Hormone which regulate gene expression or chromosome by interation of hormone receptor complex with the genome are
Description : `Ca^(+2),IP_(3),C-AMP` etc. Are generated after binding of hormone on receptor present on membrane thus these are termed as
Last Answer : `Ca^(+2),IP_(3),C-AMP` etc. Are generated after binding of hormone on receptor present on membrane thus these are termed as
Description : Binding of growth hormone to its receptor results in increased transcription of (A) c-fos gene (B) c-myc gene (C) p-53 gene (D) None of these
Last Answer : Answer : A
Description : Binding of growth hormone to its receptor results in phosphorylation of (A) JAK-2 (B) Growth hormone receptor (C) STATs (D) All of these
Description : Hormone that bind to cell surface receptor and require the second messenger camp is (A) Antidiuretic hormone (B) Cholecystokinin (C) Calcitriol (D) Gastrin
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 : According to the accepted concept of hormone action, if receptor molecules are removed from target organs, then the target organ will (a) continue to respond to the hormone without any difference ( ... require higher concentration (d) continue to respond to the hormone but in the opposite way.
Last Answer : (b) not respond to the 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 : 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 : The protein IRS-1 is phosphorylated by (A) Protein kinase A (B) Protein kinase C (C) Tyrosine kinase activity of insulin receptor (D) Tyrosine kinase activity of IGF-1 receptor
Description : All the following statements about epidermal growth factor are true except (A) It is a protein (B) It possess quaternary structure (C) Its receptor is made up of a single polypeptide chain (D) Its receptor possesses tyrosine kinase domain
Description : Vitamin A is required for the formation of a light receptor protein known as (A) Globulin (B) Lypoprotein (C) Chomoprotein (D) Rhodospin
Description : A _____ is a protein receptor on the surface of macrophages, dendritic cells, and endothelial cells that allow them to recognize foreign cell markers. a. Toll-like receptor (TLR) b. pathogen-associated c. Membrane attack complex (MAC) d. Natural killer cells (NK)
Last Answer : b. pathogen-associated
Description : The insulin receptor is a: A. Ion channel regulating receptor B. Tyrosine protein kinase receptor C. G-protein coupled receptor D. None of the above
Last Answer : B. Tyrosine protein kinase receptor
Description : Which of the following is a G protein coupled receptor: A. Muscarinic cholinergic receptor B. Nicotinic cholinergic receptor C. Glucocorticoid receptor D. Insulin receptor
Last Answer : A. Muscarinic cholinergic receptor
Description : Agonists affect the receptor molecule in the following manner: A. Alter its amino acid sequence B. Denature the receptor protein C. Alter its folding or alignment of subunits D. Induce covalent bond formation
Last Answer : C. Alter its folding or alignment of subunits
Description : The following 5-HT receptor is not a G protein coupled receptor: A. 5-HT1 B. 5-HT2 C. 5-HT3 D. 5-HT4
Last Answer : C. 5-HT3
Description : The receptor transduction mechanism with the fastest time-course of response effectuation is: A. Adenylyl cyclase-cyclic AMP pathway B. Phospholipase C-IP3: DAG pathway C. Intrinsic ion channel operation D. Protein synthesis modulation
Last Answer : C. Intrinsic ion channel operation