The molecule of vitamin A1 contains (A) Benzene ring (B) β-Ionone ring (C) β-Carotene ring (D) None of these

1 Answer

Answer :

Answer : B

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Description : Two molecules of vitamin A can be formed from 1 molecule of (A) α-Carotene (B) β-Carotene (C) γ-Carotene (D) All of these

Last Answer : Answer : B

Description : One international Unit of vitamin A is the activity present in (A) 0.3 µg of β-Carotene (B) 0.3 µg of retinol (C) 0.6 µg of retinoic acid (D) All of these

Last Answer : Answer : B

Description : Precursor of Vitamin A is (A) α-Carotene (B) β-Carotene (C) γ-Carotene (D) All of these VITAMINS 121

Last Answer : Answer : D

Description : β-Carotene, precursor of vitamin A, is oxidatively cleaved by (A) β-Carotene dioxygenase (B) Oxygenase (C) Hydroxylase (D) Transferase

Last Answer : Answer : A

Description : β-Carotene, precursor of vitamin A, is oxidatively cleaved by (A) β-Carotene dioxygenase (B) Oxygenase \ (C) Hydroxylase (D) Transferase

Last Answer : (A) β-Carotene dioxygenase

Description : Anti-oxidant activity is present in (A) β-Carotene (B) Retinol (C) Retinoic acid (D) All of these

Last Answer : Answer : A

Description : Conversion of β-carotene into retinal requires the presence of (A) β-Carotene dioxygenase (B) Bile salts (C) Molecular oxygen (D) All of these

Last Answer : Answer : D

Description : The organism commonly used for the production of carotene is/ are β A- Phycomycesblakesleeanus B- Phycomycesblakesleeanus C- Blakesleatrispora D- all of these

Last Answer : all of these

Description : Pseudomonas aeruginosa forms a blue water soluble pigment called A-pyocyanin B- chlororaphin C- pyoverdin D-β-carotene

Last Answer : pyocyanin

Description : Anti-oxidant activity is present in (A) β-Carotene (B) Retinol (C) Retinoic acid (D) All of these

Last Answer : (A) β-Carotene

Description : Which is a pro vitamin or vitamin that has antioxidant properties? (A) Beta carotene (B) Vitamin E (C) Vitamin C (D) Vitamin D

Last Answer : Answer : B

Description : Which of the following is not a correct statement about the electrophilic substitution mechanism of benzene? (a) Benzene functions as a nucleophile. (b) Formation of a carbocation intermediate is the ... hybridized carbon in the ring. (d) The addition product is a frequently observed minor product.

Last Answer : The addition product is a frequently observed minor product.

Description : A molecule in plants comparable to haemoglobin in animals is – (1) Cytochrome (2) Cellulose (3) Chlorophyll (4) Carotene

Last Answer : (3) Chlorophyll Explanation: Hemoglobin is the, ironcontaining oxygen-transport met alloprotein in the red blood cells of all vertebrates. Similarly, Cytochromes are, in general, membrane-bound ... helm, groups and are primarily responsible for the generation of ATP via electron transport.

Description : A molecule in plants comparable to haemoglobin in animals is (1) Cytochrome (2) Cellulose (3) Chlorophyll (4) Carotene

Last Answer : Chlorophyll

Description : The cholesterol molecule is (A) Benzene derivative (B) Quinoline derivative (C) Steroid (D) Straight chain acid

Last Answer : Answer : C

Description : Synthesis of RNA molecule is terminated by a signal which is recognised by (A) α-factor (B) β-factor (C) δ-factor (D) ρ

Last Answer : Answer : D

Description : After termination of the synthesis of RNA molecule, the core enzymes separate from the DNA template. The core enzymes then recognize a promoter at which the synthesis of a new RNA molecule commences, with the assistance of (A) Rho (ρ) factor (B) δ factor (C) β factor (D) σ factor

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Description : Acetoacetyl-CoA condenses with one more molecule of acetyl-CoA to form (A) Mevalonate (B) Acetoacetate (C) β-Hydroxybutyrate (D) 3-Hydroxy 3-methyl-glutaryl-CoA

Last Answer : Answer : D

Description : Spinach leaves are rich source of---- A. Amino acid B. Iron (Answer) C. Vitamin E D. Carotene

Last Answer : B. Iron (Answer)

Description : Good vision depends on adequate intake of carotene rich food. Select the best option from the following statements. (1) Vitamin A derivatives are formed from carotene. (2) The photopigments are embedded in the membrane discs of the inner ... (1) and (3) (c) (2), (3) and (4) (d) (1) and (2)

Last Answer : (b) (1) and (3)

Description : Spinach leaves are rich source of (1) Vitamin A (2) Iron (3) Carotene (4) Vitamin E

Last Answer : (2) Iron

Description : Good vision depends on adequate intake of carotene rich food : Select the best option from the following statements : (a) Vitamin A derivatives are formed from carotene (b) The photopigments are embedded in the membrane discs of the inner segment ... (a) and (c) (3) (b), (c) and (d) (4) (a) and (b)

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Description : Night blindness is due to deficiency of vitamin: (a) A1 (b) A2 (c) D (d)B complex

Last Answer : (a) A1

Description : The β-ring of 7-dehydrocholesterol is cleaved to form cholecalciferol by (A) Infrared light (B) Dim light (C) Ultraviolet irridation with sunlight (D) Light of the tube lights

Last Answer : Answer : C

Description : Carrot is orange in colour because (1) It grows in the soil (2) It is not exposed to sunlight (3) It contains carotene (4) The entire plant is orange in colour

Last Answer : It contains carotene 

Description : In the blood the vitamin esters are attached to (A) α1-lipoproteins (B) α2-lipoproteins (C) β-lipoproteins (D) γ-lipoproteins

Last Answer : Answer : C

Description : Vitamin K is a cofactor for (A) Gamma carboxylation of glutamic acid residue (B) β-Oxidation of fatty acid (C) Formation of γ-amino butyrate (D) Synthesis of tryptophan

Last Answer : Answer : A

Description : The enzyme dopamine β-oxidase which catalyses conversion of dopamine to norepinephrine requires (A) Vitamin A (B) Vitamin C (C) Vitamin E (D) Vitamin B12

Last Answer : Answer : B

Description : Pantothenic acid contains an amino acid which is (A) Aspartic acid (B) Glutamic acid (C) β-Alanine (D) β-Aminoisobutyric acid

Last Answer : Answer : C

Description : Foetal haemoglobin contains (A) Two α and two γ chains (B) Two β and two γ chains (C) Both (A) and (B) (D) None of these

Last Answer : Answer : A

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++

Last Answer : Answer : D

Description : A molecule of CO2 is captured by biotin when it acts as coenzyme for carboxylation reaction. The carboxyl group is covalently attached to (A) A nitrogen (N1) of the biotin molecule (B) Sulphur of thiophene ring (C) α-Amino group of lysine (D) α-Amino group of protein

Last Answer : Answer : A

Description : Some hormones produce their intracellular effects by activating (A) Phospholipae A1 (B) Phospholipase B (C) Phospholipase C (D) All of these

Last Answer : Answer : C

Description : Zellweger’s syndrome is due to inherited absence of (A) Peroxisomes (B) Phospholipase A1 (C) Acyl-Co-A dehydrogenase (D) Thiolase

Last Answer : Answer : A

Description : The non-protein part of rhodopsin is (A) Retinal (B) Retinol (C) Carotene (D) Repsin

Last Answer : Answer : A

Description : Non-protein part of rhodopsin is (A) Retinal (B) Retinol (C) Carotene (D) Repsin

Last Answer : Answer : A

Description : Lysolecithin is formed from lecithin by the action of (A) Phospholipase A1 (B) Phospholipase A2 (C) Phospholipase C (D) Phospholipase D

Last Answer : Answer : B

Description : Anti-inflammatory corticosteroids inhibit (A) Phospholipase A1 (B) Phospholipase A2 (C) Cyclo-oxygenase (D) Lipo-oxygenase

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Description : Phenylbutazone and indomethacin inhibit (A) Phospholipase A1 (B) Phospholipase A2 (C) Cyclo-oxygenase (D) Lipo-oxygenase

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Description : Glutathione is a constituent of (A) Leukotriene A4 (B) Thromboxane A1 (C) Leukotriene C4 (D) None of these

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Description : A ’suicide enzyme’ is (A) Cycloxygenase (B) Lipooxygenase (C) Phospholipase A1 (D) Phospholipase A2

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Description : Aspirin inhibits the activity of the enzyme: (A) Lipoxygenase (B) Cyclooxygenase (C) Phospholipae A1 (D) Phospholipase A2

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Description : Which of the following statements are false about benzene? (a) It is a planar molecule with bond angles 120°. (b) It is immiscible with water forming the lower layer. (c) It can be ... Ni catalyst. (d) It reacts with ethyl chloride in the presence of aluminium chloride to form ethylbenzene.

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Description : Which of the following statements about benzene is correct? (a) All of the carbon atoms are sp3 hybridized. (b) It has no delocalized electrons. (c) The carbon-carbon bond length is longer than that of ethane. (d) It is a planar molecule.

Last Answer : It is a planar molecule.

Description : Which of the following statements are correct concerning benzene? (a) Benzene is a planar molecule. (b) The six carbon-carbon bonds have the same length. (c) Benzene has alternating single and double bonds. (d) (a) and (b)

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Description : The electrophile, `E^((o+))` attacks the benzene ring to generate the intermediate `sigma`-complex. Of the following which `sigma`-complex is of lowes

Last Answer : The electrophile, `E^((o+))` attacks the benzene ring to generate the intermediate `sigma`-complex. Of the ... is of lowest energy? A. B. C. D.

Description : How an — OH group attached to carbon in the benzene ring activates benzene towards electrophilic substitution ?

Last Answer : The lone pair of electrons present on oxygen atom enter into resonance with the benzene ring. As a result, the electron density becomes higher at o- and p- position and due to higher electron density, the ring gets activated towards electrophilic substitution.

Description : Benzene ring was proposed by

Last Answer : Kekule.

Description : How many isomers containing a benzene ring correspond to the formula C6H4(COOH)2? (a) 1 (b) 2 (c) 3 (d) 4

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Description : The carbon atoms in a benzene ring are : (a) sp hybridized (b) sp3 hybridized (c) sp2 hybridized (d) None of these

Last Answer : sp2 hybridized