Tag: the origin of cells and cell division
Questions Related to the origin of cells and cell division
Which enzyme is concerned with transfer of electrons?
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Desmolase
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Hydrolase
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Dehydrogenase
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Transaminase
Enzyme amylase belongs to class
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Transferases
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Hydrolases
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Isomerases
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Oxidoreductases
Hydrolases are the enzymes which break large molecules into smaller ones with the help of hydrogen and hydroxyl groups of water molecules, this phenomenon is known as hydrolysis. Amylase is the enzyme produced by the salivary gland and is found in saliva. It breaks starch into glucose. Thus, the correct answer is B.
Ribozyme is
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RNA with enzyme activity
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RNA without sugar
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RNA without phosphate
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RNA with extra phosphate
Ribozymes are also known as ribonucleic acid enzymes. These are RNA molecules which helps in the catalysis of a particular reaction. It was discovered in the year 1982. The RNA can act as both genetic material and can act as a biocatalyst. It acts as a part of ribosome which attaches to the amino acid during protein synthesis. It increases the rate and specificity of peptide bond synthesis and phosphodiester bond. So, the correct answer is option A.
Nickel is component of
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PEP carboxylase
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Rubisco
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Urease
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Nitrate reductase
Urease is a nickel-containing metalloprotein which catalyzes the hydrolysis of urea into carbon dioxide and ammonia. Due to the production of ammonia, it increases the production of ammonia. Sumner crystallized an enzyme known as urease and reported that all enzymes are protein. Heliobacter pylori are microbial ureases found in the stomach.
Which is false about prosthetic groups?
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Proteins
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Non-proteins
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Metal compounds
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Tightly bound to enzymes
Many enzymes show enzymatic activity only in association with certain non protein substances. Such substances are known as cofactors. Cofactors may be simple ions such as magnesium or potassium ions or complex organic compounds. An organic non-protein cofactor which is easily separable from the enzyme is called coenzyme and the non-protein organic cofactor which is tightly bound to and non-dissociable from the enzyme is termed as prosthetic group. The organic cofactors directly reduce the activation energy and thus form a functional part of active site of enzyme. They act as carriers of chemical groups, atoms or electrons removed from the substrates during reactions.
Enzymes with heme as prosthetic group are
(a) Catalase
(b) Carboxypeptidase
(c) Succinic dehydrogenase
(d) Peroxidase
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a and d
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a ony
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a and b
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b and c
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c and a
Certain enzymes are made up of two parts - a protein part of enzyme called apoenzyme and a non-protein part called cofactor. Such enzymes are called conjugated enzymes. The working combination of apoenzyme and cofactor together form the holoenzyme. Organic cofactors are of two types- coenzymes and prosthetic groups. Coenzymes are easily separable organic cofactors while prosthetic groups are non-protein organic cofactors firmly associated with protein part of enzyme called apoenzyme. Heme is iron containing prosthetic group in hemoglobin, myoglobin, cytochrome, catalase and peroxidase. Catalase and peroxidase cause the breakdown of hydrogen peroxide to oxygen and water. Carboxypeptidase requires zinc for its activity.
Match and find the correct option.
$(a)$ | Oxidoreductases | $(i)$ | Linking of the compounds |
---|---|---|---|
$(b)$ | Isomerases | $(ii)$ | Removal of group from substrate |
$(c)$ | Ligases | $(iii)$ | Interconversion of isomers |
$(d)$ | Lyases | $(iv)$ | Dehydrogenases |
$(v)$ | Hydrolysis |
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$a - iv, b - i, c - iii, d - ii$
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$a - iv, b - iii, c - i, d - ii$
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$a - iii, b - iv, c - ii, d - v$
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$a - ii, b - v, c - iii, d - i$
A simple enzyme is
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Succinate dehydrogenase
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Urease
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Transaminase
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Ribozyme
Ribozyme was discovered by
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Kuhne
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Duclaux
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Cech et al
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Altman et al
Ribozymes are also known as ribonucleic acid enzymes. These are RNA molecules which helps in the catalysis of a particular reaction. It was discovered in the year 1982. The RNA can act as both genetic material and can act as a biocatalyst. It acts as a part of ribosome which attaches to the amino acid during protein synthesis. Thomas R. Cech and Sidney Altman discovered catalytic properties of RNA. So, the correct answer is option D.
Hydrolytic enzymes which act on low pH are called as : -
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Protease
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-Amylase
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Hydrolases
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Peroxidase