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 : 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 : 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 : 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 : 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 : How does steroid hormone influence the cellular activities? (a) Using aquaporin channels ‘as second messenger’ (b) Changing the permeability of the cell membrane (c) Binding to DNA and forming a gene-hormone complex (d) Activating cyclic AMP located on the cell membrane
Last Answer : (c) Binding to DNA and forming a gene-hormone complex
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 : 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 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 : 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
Last Answer : Answer : B
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 : 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 : 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
Description : Insulin binding sites are present on the (A) α-subunits of insulin receptor (B) β-subunits of insulin receptor (C) γ-subunits of insulin receptor (D) α-and β−subunits of insulin receptor
Description : The transport of proteins out of the cell is termed exocytosis. Which of the following statement(s) is/are true concerning this process? a. Secretory vesicles fuse with the plasma membrane b. ... or a neurotransmitter d. A decrease in cytoplasmic calcium occurs as part of the secretion process
Last Answer : Answer: a, b, c Transport vesicles that bud off the Golgi network carry both material to be secreted from the cell and protein destined to become components of the plasma ... but may also involve generation of diacylglycerol or production of cyclic AMP which activate kinases or phosphatases
Description : `IP_(1),IP_(2),IP_(3),IP_(4) and IP_(5)` for an element is 7.1,14.3,34.5,46.8 and 162.2 eV respectively then element is :-
Last Answer : `IP_(1),IP_(2),IP_(3),IP_(4) and IP_(5)` for an element is 7.1,14.3,34.5,46.8 and 162.2 eV respectively then element is :- A. Na B. Si C. F D. Ca
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 : Receptor sites for neurotransmitters are present on (a) pre-synaptic membrane (b) tips of axons (c) post-synaptic membrane (d) membranes of synaptic vesicles.
Last Answer : (c) post-synaptic membrane
Description : Receptor sites for neurotransmitters are present on : (1) Pre-synaptic membrane (2) Tips of axons (3) Post-synaptic membrane (4) Membrane of synaptic vesicles
Last Answer : (3) Post-synaptic membrane
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 : 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
Description : Fibronectin has binding sites for all of the following except (A) Glycophorin (B) Collagen (C) Heparin (D) Integrin receptor
Description : Binding of insulin to its receptor activates (A) Adenylate cyclase (B) Guanylate cyclase (C) Phospholipase C (D) Tyrosine kinase
Description : _____ cells have antibodies on their surface that perform receptor functions by binding to antigen (epitope). a. T b. B c. NK d. A-C are correct
Last Answer : b. B
Description : The _____ cell contains on its surface a CD4 receptor site that enhances binding to the macrophage. a. Helper T b. molecular patterns (PAMPs) c. plasma d. B
Last Answer : a. IgG
Description : Clonal selection includes a. Antigen-receptor binding on B cells. b. Antibody secretion recognizing same epitope as on B cell receptors. c. Differentiation of B cells into plasma cells and memory cells. d. All the above (A—C) are correct.
Last Answer : d. All the above (A—C) are correct.
Description : The function of a viral capsid is A.protection against the viral genome from physical and enzymatic destruction B.providing binding sites that enable the virus to attach to specific receptor sites on the host ... C.serving as a vehicle of transmission from one host to another D.all of the above
Last Answer : D.all of the above
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 : Numerous antibodies can be prepared, against one antigen, each binds to unique epitopes. How is this antibody diversity generated? A- By rearrangements of the DNA encoding the variable regions of the heavy ... proteins can physically change their shape to bind different epitopes D- Both (a) and (b)
Last Answer : Both (a) and (b)
Description : A diagram showing axon terminal and synapse is given. Identify correctly at least two of A - D. (a) A - Neurotransmitter, B - Synaptic cleft (b) C - Neurotransmitter, D - Ca++ (c) A - Receptor, C - Synaptic vesicles (d) B - Synaptic connection, D - K+
Last Answer : (c) A - Receptor, C - Synaptic vesicles
Description : By which of the following means antifungal chemotherapeutic agents may affect fungi? A- Interfere with nuclear division by preventing the aggregation of microtubules needed for mitosis B- ... membrane-bound enzymes like thoseinvolved in nutrient transport and chitin synthesis D- all of these
Last Answer : all of these
Description : According to Coast Guard Regulations (46 CFR), a battery installation must be in a room that is only for batteries or a box on deck. This would be termed a ____________. A. small installation B. moderate installation C. large installation D. high amp/hour capacity installation
Last Answer : Answer: C
Description : Thyroid stimulating hormone is a dimer. The α-subunits of TSH, LH, FSH are identical. Thus the biological specificity must therefore be β subunit in which the number of amino acids is (A) 78 (B) 112 (C) 130 (D) 199
Description : Enhanced facultative reabsorption of water by Vasopressin is mediated by (A) Cyclic AMP (B) Ca++ (C) Cyclic GMP (D) Mg++
Description : The excess energy of reactants in a chemical reaction required to dissociate into products is termed as the __________ energy. (A) Activation (B) Potential (C) Binding (D) Threshold
Last Answer : (A) Activation
Description : Which are the cholesterol esters that enter cells through the receptor-mediated endocytosis of lipoproteins hydrolyzed? (A) Endoplasmin reticulum (B) Lysosomes (C) Plasma membrane receptor (D) Mitochondria
Last Answer : B
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 : Which of the following receptors does not span the cell membrane 7 times a. β-Adrenergic receptor b. Rhodopsin c. 5-HTic receptor d. Mineralocorticoid receptor
Last Answer : Mineralocorticoid 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 : 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 : e primary mechanism by which general anaesthetics produce their action is: A. Affecting receptor operated ion channels in cerebral neurones B. Blocking voltage sensitive Na+ channels in neuronal ... activity of cerebral neurones D. Blocking production of high energy phosphates in the brain
Last Answer : A. Affecting receptor operated ion channels in cerebral neurones
Description : The following is not true of local anaesthetics: A. The local anaesthetic is required in the unionized form for penetrating the neuronal membrane B. The local anaesthetic approaches its receptor ... the resting state D. The local anaesthetic combines with its receptor in the ionized cationic form
Last Answer : C. The local anaesthetic binds to its receptor mainly when the Na+ channel is in the resting state
Description : The glucocorticoid receptor is located: A. On the outer surface of the cell membrane B. On the inner surface of the cell membrane C. In the cytoplasm D. Inside the nucleus
Last Answer : C. In the cytoplasm
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 : Actions of 5-HT2 receptor activation are primarily mediated by: A. Increased membrane permeability to Na+ ions B. Increased formation of cAMP C. Activation of guanylyl cyclase D. Generation of inositol trisphosphate and diacyl glycerols
Last Answer : D. Generation of inositol trisphosphate and diacyl glycerols
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