Description : Proteins are synthesized in— (A) Centrosomes (B) Ribosomes (C) Mitochondria (D) Golgi bodies
Last Answer : (B) Ribosomes
Description : The proteins are synthesised at (a) centrosomes (b) Golgi bodies (c) ribosomes (d) mitochondria.
Last Answer : (c) ribosomes
Description : Chain elongation of fatty acids occurring in mammalian liver takes place in which of the following subcellular fractions of the cell? (A) Nucleus (B) Ribosomes (C) Lysosomes (D) Microsomes
Last Answer : Answer : D
Description : In biosynthesis of proteins the chain terminating codons are (A) UAA, UAG and UGA (B) UGG, UGU and AGU (C) AAU, AAG and GAU (D) GCG, GCA and GCU
Last Answer : Answer : A
Description : Identify the correct molecule which controls the biosynthesis of proteins in living organisms. (A) DNA (B) RNA (C) Purines (D) Pyrimidines
Description : For biosynthesis of proteins (A) Amino acids only are required (B) Amino acids and nucleic acids only are required (C) Amino acid, nucleic acids and ATP only are required (D) Amino acids, nucleic acids, ATP, GTP, enzymes and activators are required
Description : Ketogenesis is taking place in which subcellular organelle?
Last Answer : Mitochondria.
Description : The signal sequence of proteins is cleaved off (A) On the ribosomes immediately after synthesis (B) In the endoplasmic reticulum (C) During processing in Golgi apparatus (D) During passage through the cell membrane
Last Answer : Answer : B
Description : The proteins destined to be transported out of the cell have all the following features except (A) They possess a signal sequence (B) Ribosomes synthesizing them are bound to endoplasmic reticulum (C) After synthesis, they are delivered into Golgi apparatus (D) They are tagged with ubiquitin
Description : Transfer RNA transfers (A) Information from DNA to ribosomes (B) Information from mRNA to cytosol (C) Amino acids from cytosol to ribosomes (D) Proteins from ribosomes to cytosol
Last Answer : Answer : C
Description : Find incorrect statement with regard to centrosome and centrioles :- (a) Centrosomes are surrounded by amorphous pericentriolar material (b) In centro
Last Answer : Find incorrect statement with regard to centrosome and centrioles :- (a) Centrosomes are surrounded by amorphous ... b C. b, c D. All are correct
Description : How may cells be disrupted in order to obtain subcellular organelles by centrifugal fractionation?
Last Answer : There are several ways of disrupting cells: 1. Osmotic lysis. The plasma membranes of cells are water-permeable but are impermeable to large molecules and some ions. Thus if cells are placed ... cause microcavitation in the sample, and this disrupts the cell membranes, usually in a few seconds.
Description : Which is correct about cell theory in view of current status of our knowledge about cell structure? (a) It needs modification due to discovery of subcellular structures like chloroplasts and ... Cell theory means that all living objects consists of cells whether or not capable of reproducing
Last Answer : (c) Cell theory does not hold good because all living beings (e.g., viruses) do not have cellular organisation.
Description : Which organelle does assemble ribosomes? (a) Nuclear envelope (b) Nucleolus (c) Chromosomes (d) Nucleoplasm
Last Answer : Ans:(b)
Description : Synapsis occurs between (a) mRNA and ribosomes (b) spindle fibres and centromere (c) two homologous chromosomes (d) a male and a female gamete.
Last Answer : (c) two homologous chromosomes
Description : Cellular organelles with membranes are (a) endoplasmic reticulum, ribosomes and nuclei (b) lysosomes, Golgi apparatus and mitochondria (c) nuclei, ribosomes and mitochondria (d) chromosomes, ribosomes and endoplasmic reticulum.
Last Answer : (b) lysosomes, Golgi apparatus and mitochondria
Description : Which of the following is not true for prokaryotic organism? A.Nucleus is not bounded by nuclear membrane B.Chromosomes does not contain histones C.80S ribosomes are distributed in cytoplasm D.Cell wall contains peptidoglycan as one of the major component
Last Answer : C.80S ribosomes are distributed in cytoplasm
Description : Which of the following is not true for prokaryotic organism? A- Nucleus is not bounded by nuclear membrane B- Chromosomes does not contain histones C- 80S ribosomes are distributed in cytoplasm D- Cell wall contains peptidoglycan as one of the major component
Last Answer : 80S ribosomes are distributed in cytoplasm
Description : Which of the following is not true for eukaryotic cells? A- Nucleus is bounded by nuclear membrane B- Chromosomes contain histones C- Chloroplasts and mitochondria contains 70S ribosomes D- Gas vacuoles are present
Last Answer : Gas vacuoles are present
Description : The chromosomes responsible for characteristics other than sex are known by which of the following terms? a) ribosomes b) lysosomes c) autosomes d) spermatocytes
Last Answer : ANSWER: C -- AUTOSOMES
Description : Site of enzyme synthesis in a cell is (A) Ribosomes (B) RER (C) Golgi bodies (D) All of these
Description : Is it true that proteins are made on the ribosomes in the cytoplasm?
Last Answer : Feel Free to Answer
Description : In the bacteria: (1) Mesosome is present (2) Nucleoid represents the genome (3) Ribosomes are found in cytoplasm (4) Histone proteins complexed with DNA
Last Answer : Ans. ((a))
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 : Ribosomes help to synthesize a. carbohydrates b. proteins c. lipids d. minerals
Last Answer : proteins
Description : Nissl’s bodies are mainly composed of (a) proteins and lipids (b) DNA and RNA (c) nucleic acids and SER (d) free ribosomes and RER.
Last Answer : (d) free ribosomes and RER.
Description : What is true about ribosomes? (a) The prokaryotic ribosomes are 80S, where “S” stands for sedimentation coefficient. (b) These are composed of ribonucleic acid and proteins. (c) These are found only in eukaryotic cells. (d) These are self-splicing introns of some RNAs
Last Answer : (b) These are composed of ribonucleic acid and proteins.
Description : Which of the following statements regarding mitochondria is incorrect? (a) Mitochondrial matrix contains single circular DNA molecule and ribosomes. (b) Outer membrane is permeable to monomers of ... transport are embedded in outer membrane. (d) Inner membrane is convoluted with infoldings.
Last Answer : (c) Enzymes of electron transport are embedded in outer membrane.
Description : Nissl bodies are mainly composed of (1) Proteins and lipids (2) DNA and RNA (3) Nucleic acids and SER (4) Free ribosomes and RER
Last Answer : (4) Free ribosomes and RER
Description : What is true about ribosomes ? (1) These are self - splicing introns of some RNAs (2) The prokaryotic ribosomes are 80S, where “S” stands for sedimentation coefficient (3) These are composed of ribonucleic acid and proteins (4) These are found only in eukaryotic cells
Last Answer : (3) These are composed of ribonucleic acid and proteins
Description : Modification of proteins and lipids as glycopeptides and lipo-proteins occur in (A) Ribosomes (B) Golgi apparatus (C) SER (D) All A, B and C
Last Answer : (B) Golgi apparatus
Description : The difference between smooth and rough endoplasmi reticulum is the lack of: a) ATP b) proteins c) ribosomes d) peroxisomes
Last Answer : ANSWER: C -- RIBOSOMES
Description : In the biosynthesis of c-DNA, the joining enzyme ligase requires (A) GTP (B) ATP (C) CTP (D) UTP
Description : A key substance in the committed step of pyrimidines biosynthesis is (A) Ribose-5-phosphate (B) Carbamoyl phosphate (C) ATP (D) Glutamine
Description : The enzyme aspartate transcarbamoylase of pyrimidine biosynthesis is inhibited by (A) ATP (B) ADP (C) AMP (D) CTP
Description : An enzyme of pyrimidine nucleotides biosynthesis regulated at the genetic level by apparently coordinate repression and derepression is (A) Carbamoyl phosphate synthetase (B) Dihydroorotate dehydrogenase (C) Thymidine kinase (D) Deoxycytidine kinase
Description : An enzyme of pyrimidine nucleotide biosynthesis sensitive to allosteric regulation is (A) Aspartate transcarbamoylase (B) Dihydroorotase (C) Dihydroorotate dehydrogenase (D) Orotidylic acid decarboxylase
Description : A substrate for enzymes of pyrimidine nucleotide biosynthesis is (A) Allopurinol (B) Tetracylin (C) Chloramphenicol (D) Puromycin
Description : Pyrimidine biosynthesis begins with the formation from glutamine, ATP and CO2, of (A) Carbamoyl aspartate (B) Orotate (C) Carbamoyl phosphate (D) Dihydroorotate
Description : Pyrimidine and purine nucleoside biosynthesis share a common precursor: (A) PRPP (B) Glycine (C) Fumarate (D) Alanine
Description : Purine biosynthesis is inhibited by (A) Aminopterin (B) Tetracyclin (C) Methotrexate (D) Chloramphenicol
Description : In the biosynthesis of purine nucleotides the AMP feed back regulates (A) Adenylosuccinase (B) Adenylosuccinate synthetase (C) IMP dehydrogenase (D) HGPR Tase
Description : The major determinant of the overall rate of denovo purine nucleotide biosynthesis is the concentration of (A) 5-phosphoribosyl 1-pyrophosphate (B) 5-phospho β-D-ribosylamine (C) Glycinamide ribosyl-5-phosphate (D) Formylglycinamide ribosyl-5-phosphate
Description : In purine biosynthesis ring closure in the molecule formyl glycinamide ribosyl-5- phosphate requires the cofactors: (A) ADP (B) NAD (C) FAD (D) ATP and Mg++
Description : In purine biosynthesis carbon atoms at 4 and 5 position and N at 7 position are contributed by (A) Glycine (B) Glutamine (C) Alanine (D) Threonine
Description : In the biosynthesis of testosterone the rate limiting step is conversion of (A) Cholesterol to pregnenolone (B) Pregnenolone to progesterone (C) Progesterone to 17 α-hydroxy progesterone (D) 17 α-Hydroxy progesterone to androstenedione
Description : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase
Description : For Catecholamine biosynthesis the rate limiting enzyme is (A) DOPA decarboxylase (B) DOPAMINE β-hydroxylase (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase
Description : In the biosynthesis of cortiol, the sequence of enzymes involved is (A) Hydroxylase–dehydrogenase + isomerase – hydroxylase (B) Dehydrogenase–hydroxylase–isomerase (C) Hydroxylase–lyase–dehydrogenase isomerase (D) Isomerase–lyase–hydroxylase–dehydrogenase
Description : A very efficient inhibitor of steroid biosynthesis is (A) Aminoglutethimide (B) Aminoimidazole (C) Aminoimidazolesuccinyl carboxamine (D) Aminopterin