Description : In the insulin receptor, tyrosine kinase domain is present in (A) α-Subunits (B) β-Subunits (C) γ-Subunits (D) δ-Subunits
Last Answer : Answer : B
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 : 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 : Hemoglobin is a molecule made of four polypeptide chains, each bound to a iron-containing molecular group called a heme group. So the molecule contains four polypeptide chains and four ... depends upon the integrity of its quaternary structure. Blood Questions - Image Diversity: hemoglobin molecule
Last Answer : On average what is the life duration of the red blood cells?
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 : 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 : Binding of insulin to its receptor activates (A) Adenylate cyclase (B) Guanylate cyclase (C) Phospholipase C (D) Tyrosine kinase
Last Answer : Answer : D
Description : The following protein/polypeptide has a quaternary structure : (A) cc-Chymotrypsin (B) Hemoglobin (C) Insulin (D) Myoglobin
Last Answer : (B) Hemoglobin
Description : Tyrosine kinase activity is present in (A) Acetylcholine receptor (B) PDGF receptor (C) ADH receptor (D) All of these
Description : Ras proto-oncogene encodes (A) Epidermal growth factor (EGF) (B) Receptor for EGF (C) Signal transducer for EGF (D) Nuclear transcription factor
Last Answer : Answer : C
Description : Which of the following is the quaternary structure of proteins concerned with? (a) sequence of amino acids in the peptide chain (b) description of the way the peptide chains are arranged with ... (c) location of the disulfide bridges in the peptide chain (d) conformation of the protein backbone
Last Answer : description of the way the peptide chains are arranged with respect to each other
Description : All the following statements about ceruloplasmin are correct except (A) It is a copper-containing protein (B) It possesses oxidase activity (C) It is synthesised in intestinal mucosa (D) Its plasma level is decreased inWilson’s disease
Description : Which of the following statements about nerve growth factor is not true a. it is made up of 3 polypeptide subunits b. it is found in high concentration in the submaxillary salivery gland c. it is picked up by nerves from the organs they innervate d. it is present in brain
Last Answer : it is found in high concentration in the submaxillary salivery gland
Description : Which of the following statements regarding fibroblasts and their function in wound healing are true? a. IL-1 has both inhibitory and promotional effects on fibroblast growth b. TNFa ... EGF (epithelial growth factor) has been demonstrated to accelerate epidermal regeneration in cutaneous wounds
Last Answer : Answer: a, d IL-1 appears to be important in the process of normal wound repair. IL-1 has been shown to stimulate skin fibroblast and keratinocyte growth, as well as ... that recombinant EGF enhances keratinocyte migration. EGF is also a potent chemoattractant for granulation tissue fibroblasts
Description : The primary structure of a protein refers to : (a) whether the protein is fibrous or globular (b) the amino acid sequence in the polypeptide chain (c) the orientation of the amino acid side chains in space (d) the presence or absence of an α-helix
Last Answer : the amino acid sequence in the polypeptide chain
Description : Agonist induced autophosphorylation, internalization and down regulation is a distinctive feature of: A. G-protein coupled receptors B. Intrinsic ion channel containing receptors C. Tyrosine protein kinase receptors D. Receptors regulating gene expression
Last Answer : C. Tyrosine protein kinase receptors
Description : Insulin is made up of (A) A single polypeptide chain having 51 amino acid residues (B) A single polypeptide chain having 84 amino acid residues (C) A-chain having 21 and B-chain having 30 amino acid residues (D) A-chain having 30 and B-chain having 21 amino acid residues
Description : The figure below shows the structure of a mitochondrion with its four parts labelled A, B, C and D. Select the part correctly matched with its function. D B A C (a) D (outer ... possesses single circular DNA molecule and ribosomes (d) A (matrix) - major site for respiratory chain enzyme
Last Answer : (b) B (inner membrane) – forms infoldings called cristae
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 : During denaturation of proteins, all of the following are disrupted except (A) Primary structure (B) Secondary structure (C) Tertiary structure (D) Quaternary structure
Description : In protein structure the α-helix and βpleated sheets are example of (A) Primary structure (B) Secondary structure (C) Tertiary structure (D) Quaternary structure
Description : All the following statements about TSH are true except (A) It is a glycoprotein (B) It is made up of α- and β-subunits (C) Receptor recognition involves both the subunits (D) Its subunit is identical with those of FSH and LH
Description : All the following statements about βendorphin are true except µ : (A) It is a polypeptide (B) Its precursor is pro-opio-melanocortin (C) Its receptors are represent in brain (D) Its action is blocked by morphine
Description : Human growth hormone has (A) One polypeptide chain and one intra-chain disulphide bond (B) One polypeptide chain and two intra-chain disulphide bond (C) Two polypeptide chains joined by one disulphide bond (D) Two polypeptide chains joined by two disulphide bond
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 : Tyrosine kinase activity is present in (A) α-Adrenergic receptors (B) β-Adrenergic receptors (C) Cholinergic receptors (D) Insulin receptors
Description : __________ hormone is a single chain polypeptide having 32 amino acids with molecular weight of 3,600. (A) Testosteron (B) Thyroxine (C) Calcitonine (D) Vasopressin
Description : The number of amino acids in single chain polypeptide glucagons is (A) 21 (B) 29 (C) 31 (D) 39
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 : What bonds hold together the Quaternary structure of protein? -Biology
Last Answer : answer:
Description : The _______ structure of a protein is the sequence of amino acids. a. primary b. secondary c. tertiary d. quaternary
Last Answer : a. primary
Description : All the following statements about albinism are correct except (A) Tyrosine hydroxylase (tyrosinase) is absent or deficient in melanocytes (B) Skin is hypopigmented (C) It results in mental retardation (D) Eyes are hypopigmented
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 : What is epidermal growth factor used for?
Last Answer : Simply put, epidermal growth factor (EGF) is a mitogenic protein, and it is used to stimulate cell growth.
Description : In quaternary structure, subunits are linked by (A) Peptide bonds (B) Disulphide bonds (C) Covalent bonds (D) Non-covalent bonds
Description : In proteins the α-helix and β-pleated sheet are examples of (A) Primary structure (B) Secondary structure (C) Tertiary structure (D) Quaternary structure
Description : What is meant by quaternary structure of a pro- tein?
Last Answer : Certain polypeptides will aggregate to form one functional protein. This is referred to as the qua- ternary structure.
Description : In prokaryotes, chloramphenicol (A) Causes premature release of the polypeptide chain (B) Causes misreading of the mRNA (C) Depolymerises DNA (D) Inhibits peptidyl transferase activity
Last Answer : Answer : A
Description : The amino terminal of all polypeptide chain at the time of synthesis in E. coli is tagged to the amino acid residue: (A) Methionine (B) Serine (C) N-formyl methinine(D) N-formal serine
Description : At the lowest energy level α-helix of polypeptide chain is stabilised (A) By hydrogen bonds formed between the H of peptide N and the carbonyl O of the residue (B) Disulphide bonds (C) Non polar bonds (D) Ester bonds
Description : Globular proteins have completely folded, coiled polypeptide chain and the axial ratio (ratio of length to breadth) is (A) Less than 10 and generally not greater than 3–4 (B) Generally 10 (C) Greater than 10 and generally 20 (D) Greater than 10
Description : In glycoproteins, carbohydrate residues are attached to which group of the polypeptide chain?
Last Answer : Hydroxyl group of serine or threonine.
Description : All the following statements about carnitine are true except (A) It can be synthesised in the human body (B) It can be synthesized from methionine and lysine (C) It is required for transport of short chain fatty acids into mitochondria (D) Its deficiency can occur due to haemodialysis
Description : List several general cellular processes regulated by receptor tyrosine kinases (RTKs).
Last Answer : Cell growth, cell differentiation and cell survival (i.e. nutrient and stress signaling).
Description : All of the following statements about nonsense codons are true except (A) They do not code for amino acids (B) They act as chain termination signals (C) They are identical in nuclear and mitochondrial DNA (D) They have no complementary anticodons
Description : All of the following statements about hypoglycin are true except (A) It is a plant toxin (B) It causes hypoglycaemia (C) It inhibits oxidation of short chain fatty acids (D) It inhibits oxidation of long chain fatty acids
Description : In the B chain of insulin molecule, the C-terminal amino acid: (A) Threonine (B) Tyrosine (C) Glutamate (D) Valine
Description : In the A chain of insulin molecule the Cterminal amino acid is (A) Asparagine (B) Threonine (C) Valine (D) Tyrosine