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 : Binding of thyroxine to its receptors (A) Activates Adenylate cyclase (B) Activates guanylate cyclase (C) Activates a stimulatory G-protein (D) Increases transcription
Last Answer : Answer : D
Description : Adenylate cyclase is activated by (A) GDP-bearing α-Subunit of G-protein (B) GTP-bearing α-Subunit of G-protein (C) GDP-bearing γ-Subunit of G-protein (D) GTP-bearing γ-Subunit of G-protein
Last Answer : Answer : B
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 : During phototransduction: a. hyperpolarisation occurs due to closure of the sodium channels b. 11-cis-retinal molecules are converted to all-trans-retinal c. transducin, a G protein converts GDP to GTP d. all above
Last Answer : all above
Description : cAMD is destroyed by (A) Adenylate cyclase (B) Phosphodiesterase (C) Synthetase phosphatase (D) Synthetase kinase
Description : Whcih of the following hormone does not activate adenylate cyclase? (A) Epinephrine (B) Glucagon (C) Parathyroid hormone (D) Insulin
Description : Binding of insulin to its receptor activates (A) Adenylate cyclase (B) Guanylate cyclase (C) Phospholipase C (D) Tyrosine kinase
Description : Adenylate cyclase is activated by (A) Insulin (B) Glucagon (C) Prostaglandin E1 (D) Ca2+ ions
Description : Cyclic AMP is formed from ATP by the enzyme adenylate cyclase which is activated by the hormone: (A) Insulin (B) Epinephrine (C) Testosterone (D) Progesterone
Last Answer : B
Description : Which of the following is activated by Cholera toxin? 1) Adenylate cyclase 2) Guanlyate cyclase 3) Peroxisome proliferator receptor (PPAR) gamma 4) Sodium/potassium ATPase 5) The glucose-sodium transporter
Last Answer : Answers-1 Cholera toxin activates adenylate cyclase with generation of cAMP.
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 : Rhodopsin contains opsin and (A) 11-cis-retinal (B) 11-trans-retinal (C) All-cis-retinal (D) All trans-retinal
Last Answer : Answer : A
Description : On exposure to light rhodopsin forms (A) All trans-retinal (B) Cis-retinal (C) Retinol (D) Retinoic acid
Description : Transducin is a (A) Signal transducer (B) Stimulatory G-protein (C) Trimer (D) All of these
Description : $ Rhodopsin of rod cells and iodospin of cone cells of retina are proteins ! Myosine and Actin are contractile proteins
Last Answer : $ Rhodopsin of rod cells and iodospin of cone cells of retina are proteins ! Myosine and Actin are ... wrong D. If both As and R are wrong.
Description : Which one of the following is the correct difference between rod cells and cone cells of our retina? Rod cells Cone cells (a) Overall Vision in poor Colour vision function light and detailed ... of retina all over retina (c) Visual acuity High Low (d) Visual pigment Iodopsin Rhodopsin contained
Last Answer : (a) Overall Vision in poor Colour vision function
Description : When light falls on rod cells (A) All-cis-retinal is converted into all-trans-retinal (B) 11-cis-retinal is converted into 11-trans-retinal (C) 11-trans-retinal is converted into all-transretinal (D) 11-cis-retinal is converted into all-trans-retinal
Description : The following conditions are required for rhodopsin regeneration: a. NADPH b. darkness c. splitting of all trans-retinal from the opsin d. all above
Description : The non-protein part of rhodopsin is (A) Retinal (B) Retinol (C) Carotene (D) Repsin
Description : Non-protein part of rhodopsin is (A) Retinal (B) Retinol (C) Carotene (D) Repsin
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 : 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 : 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 : Rod: a. contains a cilium with a "9+0" configuration. b. contains 11-trans-retinaldehyde essential for the absorption of photons c. sheds its outer segment during the day d. depolarize in response to flashes of light
Last Answer : contains a cilium with a "9+0" configuration.
Description : The importance of phospholipids as constituent of cell membrane is because they possess (A) Fatty acids (B) Both polar and nonpolar groups (C) Glycerol (D) Phosphoric acid
Description : Which one of the following statements is not correct? (a) Retinal is the light absorbing portion of visual photopigments. (b) In retina the rods have the photopigment rhodopsin while cones have three ... a derivative of vitamin C. (d) Rhodopsin is the purplish red protein present in rods only.
Last Answer : (c) Retinal is a derivative of vitamin C.
Description : Folding of newly synthesized proteins is accelerated by (A) Protein disulphide isomerase (B) Prolyl cis-trans isomerase (C) Chaperonins (D) All of these
Description : Photosensitive compound in human eye is made up of (a) opsin and retinol (b) transducin and retinene (c) guanosine and retinol (d) opsin and retinal.
Last Answer : (d) opsin and retinal.
Description : Drugs that block the a receptor on effector cells at adrenergic nerve endings (a) Antagonize the effects of isoproterenol on the heart rate (b) Antagonize some of the effects of epinephrine on ... the effects of epinephrine on adenylyl cyclase (d) Cause mydriasis (e) Decreases blood glucose levels
Last Answer : Ans: B
Description : In biosynthesis of cholesterol triparanol inhibits the activity of the enzyme: (A) ∆24 Reductase (B) Oxidosqualene-lanosterol cyclase (C) Isomerase (D) Squalene epoxidase ENZYMES 155
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 : The purplish red pigment rhodopsin contained in the rods type of photoreceptor cells of the human eye, is a derivative of
Last Answer : The purplish red pigment rhodopsin contained in the rods type of photoreceptor cells of the human eye, is a ... Vitamin B 1 C. Vitamin C D. Vitamin D
Description : The retinal pigment epithelium (RPE): a. is sensitive to hypervitaminosis A b. isomerizes all-trans-retinal to 11-cis-retinol c. does not undergo mitosis in response to injury d. secrets the outer layer of the basal lamina that forms the Bruch's membrane.
Last Answer : isomerizes all-trans-retinal to 11-cis-retinol
Description : If the eye of an animal has a great many cone cells as well as many rod cells, what does that detirmine about that animal?
Last Answer : answer:Apparently not how to spell “determine.” Is this homework?
Description : cAMP is so called because it is formed during (A) TCA cycle (B) Urea cycle (C) Rhodopsin cycle (D) It has a cyclic structure
Description : Retina contains this photo sensitive pigment. (A) Rhodopsin (B) Opsin (C) Retinol (D) Malanin
Description : Which of the following statements regarding Vitamin A is true? (A) It is not an essential Vitamin (B) It is related to tocopherol (C) It is a component of rhodopsin (D) It is also known as Opsin
Last Answer : Answer : C
Description : Retina contains this photosensitive pigment: (A) Rhodopsin (B) Opsin (C) Retinol (D) Melanin
Description : Retinoic acid is involved in the synthesis of (A) Rhodopsin (B) Iodopsin (C) Porphyrinopsin (D) Glycoproteins
Description : Retinoic acid participates in the synthesis of (A) Iodopsin (B) Rhodopsin (C) Glycoprotein (D) Cardiolipin
Description : Retinal is a component of (A) Iodopsin (B) Rhodopsin (C) Cardiolipin (D) Glycoproteins
Description : The term ‘glycocalyx’ is used for (a) a layer present between cell wall and membrane of bacteria (b) cell wall of bacteria (c) bacterial cell glyco-engineered to possess N-glycosylated proteins (d) a layer surrounding the cell wall of bacteria.
Last Answer : (d) a layer surrounding the cell wall of bacteria.
Description : Plasma membrane in eukaryotic cells is made up of - (1) Phospholipid (2) Lipoprotein (3) Phospholipo-protein (4) Phospho-protein
Last Answer : (1) Phospholipid Explanation: The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable ... . The basic function of the cell membrane is to protect the cell from its surroundings.
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 : Plasma membrane in eukaryotic cells is made up of (1) Phospholipid (2) Lipoprotein (3) Phospholipo-protein (4) Phospho-protein
Last Answer : Phospholipid
Description : a2–adrenergic receptors are associated with following except (a) Increase in phospholipase C activity (b) Increase in potassium channel conductance (c) Decrease in calcium channel conductance (d) Increase in adenylyl cyclase activity
Last Answer : Ans: D
Description : The dopamine D2 receptor has the following feature: A. It is excitatory in nature B. It is negatively coupled to adenyl cyclase C. It is selectively blocked by bromocriptine D. It is not blocked by metoclopramide
Last Answer : B. It is negatively coupled to adenyl cyclase
Description : Beta adrenergic blockers lower intraocular tension by: A. Down regulating adenylyl cyclase in ciliary body through reduced activation of β2 adrenoceptors B. Constricting ciliary blood vessels ... action on trabecular meshwork D. Reducing aqueous formation unrelated to beta adrenoceptor mediation
Last Answer : A. Down regulating adenylyl cyclase in ciliary body through reduced activation of β2 adrenoceptors