Tag: enzymes
Questions Related to enzymes
Which is not a trait of enzymes?
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Proteinaceous nature
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Specific in nature
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Speed up rate of biochemical reaction
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Used up in reaction
Enzymes are proteins which help to catalyze the biochemical reaction. The enzyme has a protein part which is not active is known as apoenzyme. It gets activated by the addition of an organic or inorganic cofactor. It is specific in nature as specific substrate bind at the active site of a particular enzyme. It increases the rate of chemical reactions without being used up. The enzymes lower the activation energy and lead to the formation of activated complex, which is also known as transition state and finally changes to the product.
Enzymes exist in the cells as
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Solid
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Crystals
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Solution
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Colloid
Enzymes are proteins which help to catalyze the biochemical reaction. The enzyme has a protein part which is not active is known as apoenzyme. It gets activated on the addition of an organic or inorganic cofactor. It exists as hydrophilic colloid in the cytoplasm which makes it inert and prevents its dissociation. The hydrophilic part of the colloid is present on the surface which interacts with the water.
Which is wrong about enzymes?
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Enzymes are mostly proteins but some are lipids also
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Enzymes are highly specific
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Enzymes require optimum pH and temperature for maximum activity
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Enzymes are denatured at high temperature
Which is true about enzymes?
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All enzymes are not proteins
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All enzymes are vitamins
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All enzymes are proteins
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All proteins are enzymes
Enzymes are protein in nature. But some enzymes like ribozymes and ribonuclease are RNA based enzymes. It is also known as ribonucleic acid enzymes. These are RNA molecules which helps in the catalysis of a particular reaction. It was discovered in year 1982. The RNA can act as both genetic material and can act as a biocatalyst but different from protein-based enzymes. 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 A.
Enzymes functional in a cell are
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Inducible, constitutive and repressible
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Inducible and repressible
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Inducible only
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Repressible only
Enzymes are inducible in nature because as the substrate molecules attaches to the active site of the enzyme, it induces a conformational change on the active site to fit in properly.
Most of hydrolytic reactions are
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Exothermic
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Endothermic
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Irreversible
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Reversible
Hydrolytic reactions are the reactions which involves breaking of the bond by the addition of water. It can be reversed by the condensation reaction where the joining of two molecule leads to release of water by formation of bonds. Saccharification is the reaction where the complex sugar molecule is broken into its component sugar molecules by hydrolysis. It can be reversed by condensation reaction.
Enzyme generally have?
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Same pH and temperature optima
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Same pH but different temperature optima
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Different pH but same temperature optima
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All wrong
The optimum temp of enzymes is 20-35°C. They become inactivated at very low temperature and denatured (destroyed) at very high temp i.e. greater than 45°C. Low molecular weight enzymes are comparatively more heat stable. In archaebacterium Pyrococcus furiosus, the optimum temperature of hydrogenase is greater than 95°C. This heat-stable enzyme enables Pyrococcus to grow at 100°C. The optimum pH of most endoenzyme is pH 7.0 (neutral pH). However, digestive enzymes can function at different pH. For example, salivary amylase act best at pH 6.8, pepsin act best at pH2 etc. Any fluctuation in pH from the optimum causes ionization of R-groups of amino acids which decrease the enzyme activity.
Serine proteases are called so because they
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They require serine for their activity
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cleave after serine residues in the substate
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Are inhibited by the presence of free serine
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Have a serine residue at their active sire
Serine proteases are enzymes that cleave peptide bonds in proteins, in which serine serves as a nucleophilic amino acid at enzyme's active site. Serine proteases are responsible for coordinating various physiological functions including digestion, immune response, blood coagulation, and reproduction. Hence, serine proteases are called so because they require serine for their activity.
Specific enzymes are needed for the break-down of a particular substance.
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True
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False
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Either
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Neither
Mark the INCORRECT statement about the enzyme carboxypeptidase.
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Zinc is the co-factor for this proteolytic enzyme
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It is exopeptidase
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It cleaves the peptide bond at N-terminal end of the polypeptide chain
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It is an enzyme of pancreatic juice