Which of the following statements about enzymes is wrong? (a) Enzymes are denatured at high temperatures. (b) Enzymes are mostly proteins but some are lipids also. (c) Enzymes are highly specific. (d) Enzymes require optimum pH and temperature for maximum activity

Which of the following statements about enzymes is
wrong?
(a) Enzymes are denatured at high temperatures.
(b) Enzymes are mostly proteins but some are lipids
also.
(c) Enzymes are highly specific.
(d) Enzymes require optimum pH and temperature
for maximum activity
by

1 Answer

Answer :

(b) Enzymes are mostly proteins but some are lipids
also.
by

Related questions

Three of the following statements about enzymes are correct and one is wrong. Which one is wrong? (a) Enzymes require optimum pH for maximal activity. (b) Enzymes are denatured at high temperature but in certain exceptional organisms they are effective even at temperatures 80° - 90°C. (c) Enzymes are highly specific. (d) Most enzymes are proteins but some are lipids.

Description : Three of the following statements about enzymes are correct and one is wrong. Which one is wrong? (a) Enzymes require optimum pH for maximal activity. (b) Enzymes are denatured at high temperature but ... - 90°C. (c) Enzymes are highly specific. (d) Most enzymes are proteins but some are lipids.

Last Answer : (d) Most enzymes are proteins but some are lipids.

20. Which one of the following statements is incorrect about enzyme catalysis? (1) Enzymes are least reactive at optimum temperature (2) Enzymes are mostly proteinous in nature (3) Enzyme action is specific (4) Enzymes are denaturated by ultraviolet rays and at high temperature

Description : 20. Which one of the following statements is incorrect about enzyme catalysis? (1) Enzymes are least reactive at optimum temperature (2) Enzymes are mostly proteinous in nature (3) Enzyme action is specific (4) Enzymes are denaturated by ultraviolet rays and at high temperature

Last Answer : Enzymes are least reactive at optimum temperature

Pick out the wrong statement. (A) Catalytic activity of enzyme catalysed reactions which is affected by temperature, pH value & chemical agents, is maximum at a temperature of about 45°C(B) Most of the enzyme catalysed reactions involve at least two substrates (C) Enzymes help in increasing the activation energy of the reaction (D) Equilibrium concentrations in enzyme catalysed reactions can be calculated by using the thermodynamic properties of substrates & prod

Description : Pick out the wrong statement. (A) Catalytic activity of enzyme catalysed reactions which is affected by temperature, pH value & chemical agents, is maximum at a temperature of about 45°C ... in enzyme catalysed reactions can be calculated by using the thermodynamic properties of substrates & prod

Last Answer : (C) Enzymes help in increasing the activation energy of the reaction

The digestability of certain denatured proteins by proteolytic enzymes (A) Decreases (B) Increases (C) Normal (D) None of these

Description : The digestability of certain denatured proteins by proteolytic enzymes (A) Decreases (B) Increases (C) Normal (D) None of these

Last Answer : Answer : A

Stem and loop structures are A- proteins that help partially denatured enzymes to recover their native configuration B- structures in DNA caused by inverted repeats C- structures at the ends of linear eukaryotic DNA molecules D- the bonds between adjacent DNA nucleotides in the same strand

Description : Stem and loop structures are A- proteins that help partially denatured enzymes to recover their native configuration B- structures in DNA caused by inverted repeats C- structures at the ends of linear eukaryotic DNA molecules D- the bonds between adjacent DNA nucleotides in the same strand

Last Answer : structures in DNA caused by inverted repeats

The pH at which an enzyme has maximum activity is known as (A) Isoelectric pH (B) Optimum pH (C) Low pH (D) High pH

Description : The pH at which an enzyme has maximum activity is known as (A) Isoelectric pH (B) Optimum pH (C) Low pH (D) High pH

Last Answer : Answer : B

All the following statements about pepsin are correct except (A) It is smaller than pepsinogen (B) It is formed by the action of HCl on its precursor (C) Its optimum pH is 1.0–2.0 (D) It hydrolyses the C-terminal and N-terminal peptide bonds of proteins

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Last Answer : Answer : D

With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct ? (1) Increasing atmospheric CO 2 concentration up to 0.05% can enhance CO 2 fixation rate (2) C 3 plants respond to higher temperatures with enhanced photosynthesis while C 4 plants have much lower temperature optimum (3) Tomato is a greenhouse crop which can be grown in CO 2 - enriched atmosphere for higher yield (4) Light saturation for CO 2 fixation occurs at 10% of full sunlight

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Last Answer : (2) C 3 plants respond to higher temperatures with enhanced photosynthesis while C 4 plants have much lower temperature optimum

Maximum enzyme activity is observed at (A) Acidic pH (B) Neutral pH (C) Basic pH (D) Optimum pH

Description : Maximum enzyme activity is observed at (A) Acidic pH (B) Neutral pH (C) Basic pH (D) Optimum pH

Last Answer : Answer : D

Which is not true about inorganic catalysts and enzymes? (A) They are specific (B) Inorganic catalysts require specific not needed by enzymes (C) They are sensitive to pH (D) They speed up the rate of chemical reaction

Description : Which is not true about inorganic catalysts and enzymes? (A) They are specific (B) Inorganic catalysts require specific not needed by enzymes (C) They are sensitive to pH (D) They speed up the rate of chemical reaction

Last Answer : Answer : B

Which of the following statements regarding evacuated tube collectors (ETC) are true? i) ETC is used for high temperatures upto 150oC ii) because of use of vacuum between two concentric glass tube, higher amount of heat is retained in ETC iii) heat loss due to conduction back to atmosphere from ETC is high iv) performance of evacuated tube is highly dependent upon the ambient temperature i & iii b) ii & iii c) i & iv d) i & ii

Description : Which of the following statements regarding evacuated tube collectors (ETC) are true? i) ETC is used for high temperatures upto 150oC ii) because of use of vacuum between two concentric glass tube, higher amount of heat is ... upon the ambient temperature i & iii b) ii & iii c) i & iv d) i & ii

Last Answer : d) i & ii

DNA po lymerase of T. aquat icus is preferred to that of E. coli in PCR because (A) It replicates DNA more efficiently (B) It doesn’t require primers (C) It is not denatured at the melting temperature of DNA (D) It doesn’t cause errors in replication

Description : DNA po lymerase of T. aquat icus is preferred to that of E. coli in PCR because (A) It replicates DNA more efficiently (B) It doesn’t require primers (C) It is not denatured at the melting temperature of DNA (D) It doesn’t cause errors in replication

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According to widely accepted “fluid mosaic model” cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statements is incorrect? (a) Proteins in cell membranes can travel within the lipid bilayer. (b) Proteins can also undergo flip-flop movements in the lipid bilayer. (c) Proteins can remain confined within certain domains of the membrane.(d) Many proteins remain completely embedded within the lipid bilayer.

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Last Answer : (b) Proteins can also undergo flip-flop movements in the lipid bilayer.

Enzymes belong to the category of (a) Proteins (b) Lipids (c) Carbohydrates (d) Steroids

Description : Enzymes belong to the category of (a) Proteins (b) Lipids (c) Carbohydrates (d) Steroids

Last Answer : Ans:(a)

Enzymes are - (1) Steroids (2) Carbohydrates (3) Proteins (4) Lipids

Description : Enzymes are - (1) Steroids (2) Carbohydrates (3) Proteins (4) Lipids

Last Answer : (2) Carbohydrates Explanation: Enzymes are proteins that speed up chemical reactions in the cell. They are highly selective catalysts, greatly accelerating both the rate and specificity of metabolic reactions. Most enzymes are proteins, although some catalytic RNA molecules have been identified.

Enzymes are - (1) Steroids (2) Carbohydrates (3) Proteins (4) Lipids

Description : Enzymes are - (1) Steroids (2) Carbohydrates (3) Proteins (4) Lipids

Last Answer : (3) Proteins Explanation: Enzymes are protein molecules in cells which work as catalysts. Most enzymes are proteins, although a few are catalytic RNA molecules; the latter are called ribozymes.

Proteins are chains of _____ that sometimes function as _____. a. monosaccharaides; energy compounds b. lipids; structural materials c. amino acids; enzymes d. disaccharides; enzymes

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Last Answer : c. amino acids; enzymes

All enzymes chemically speaking are (a) Lipids (b) Carbohydrate (c) proteins (d) All

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Last Answer : (c) proteins

Enzymes are (1) Steroids (2) Carbohydrates (3) Proteins (4) Lipids

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Last Answer : Proteins

The enzymes are basically (1) carbohydrates (2) lipids (3) proteins (4) amino acids

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What is the optimum pH of usual enzymes?

Description : What is the optimum pH of usual enzymes?

Last Answer : Usually enzymes have the optimum pH between 6 and 8.

The catalytic efficiency of two different enzymes can be compared by the (a) formation of the product (b) pH of optimum value (c) Km value (d) molecular size of the enzyme.

Description : The catalytic efficiency of two different enzymes can be compared by the (a) formation of the product (b) pH of optimum value (c) Km value (d) molecular size of the enzyme.

Last Answer : (c) Km value

Which of the following is not true regarding enzymes? (A) They catalyze only a particular type of reaction (B) They remain active even after separation from the source (C) They are destroyed after the completion of the reaction they catalyse (D) They are irreversibly destroyed at high temperature (E) Their activity depends on the pH of the solution

Description : Which of the following is not true regarding enzymes? (A) They catalyze only a particular type of reaction (B) They remain active even after separation from the source (C) They are destroyed ... They are irreversibly destroyed at high temperature (E) Their activity depends on the pH of the solution

Last Answer : Answer : C

Which of the following statements is true? (A) Enzymes have names ending ase (B) Enzymes are highly specific in their action (C) Enzymes are living organisms (D) Enzymes get activated on heating

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Which of the following statements is correct? (a) Sporopollenin can be degraded by enzymes. (b) Sporopollenin is made up of inorganic materials. (c) Sporopollenin can withstand high temperatures as well as strong acids and alkalis. (d) Sporopollenin can withstand high temperatures but not strong acids.

Description : Which of the following statements is correct? (a) Sporopollenin can be degraded by enzymes. (b) Sporopollenin is made up of inorganic materials. (c) Sporopollenin can withstand high temperatures ... strong acids and alkalis. (d) Sporopollenin can withstand high temperatures but not strong acids.

Last Answer : (c) Sporopollenin can withstand high temperatures as well as strong acids and alkalis

Enzymes activity is controlled by (A) pH of the solution (B) Temperature (C) Concentration of the enzyme (D) Concentration of the substrate (E) All of these

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Pepsin acts on denatured proteins to produce (A) Proteoses and peptones (B) Polypeptides (C) Peptides (D) Dipeptides

Description : Pepsin acts on denatured proteins to produce (A) Proteoses and peptones (B) Polypeptides (C) Peptides (D) Dipeptides

Last Answer : Answer : A

Streptomycin sulfate is not absorbed orally because it is (a) Degraded by gastrointestinal enzymes (b) Destroyed by gastric acid (c) Highly ionized at a wide range of pH values (d) Insoluble in water

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Last Answer : Ans: C

Streptomycin sulfate is not absorbed orally because it is: A. Degraded by gastrointestinal enzymes B. Destroyed by gastric acid C. Highly ionized at a wide range of pH values D. Insoluble in water

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Last Answer : C. Highly ionized at a wide range of pH values

Selectins are proteins that can recognise specific (A) Carbohydrates (B) Lipids (C) Amino acids (D) Nucleotides

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Last Answer : Answer : A

The temperature at which the catalytic activity of the catalyst is maximum, is called (1) room temperature (2) critical temperature (3) absolute temperature (4) optimum temperature

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Last Answer : d) optimum temperature

Molten sodium (as a coolant in fast breeder reactor) (A) Can’t attain high temperature at normal pressure (B) Is not at all corrosive, even at a higher temperature (C) Is highly radioactive at elevated temperatures and can cause explosion, when it comes in contact with air or water (D) None of these

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Last Answer : (C) Is highly radioactive at elevated temperatures and can cause explosion, when it comes in contact with air or water

Consider the following statements - 1. Cuba is considered the sugar bowl of the world 2. Sugar was a rare commodity in Europe till the middle ages 3. Honey is a rich source of vitamins and minerals 4. All green plants synthesize sugar that are subsequently converted into lipids, polysaccharides, and/or proteins Which of the above statement/s is/are true? (a) Only 1 (b) 1 and 3 (c) 2 and 3 (d) 2 and 4

Description : Consider the following statements - 1. Cuba is considered the sugar bowl of the world 2. Sugar was a rare commodity in Europe till the middle ages 3. Honey is a rich source of vitamins and minerals 4. All green plants synthesize sugar ... is/are true? (a) Only 1 (b) 1 and 3 (c) 2 and 3 (d) 2 and 4

Last Answer : Ans:(d)

If for some reason the parietal cells of the gut epithelium become partially non-functional, what is likely to happen? (a) The pancreatic enzymes and specially the trypsin and lipase will not work efficiently. (b) The pH of stomach will fall abruptly. (c) Steapsin will be more effective. (d) Proteins will not be adequately hydrolysed by pepsin into proteoses and peptones.

Description : If for some reason the parietal cells of the gut epithelium become partially non-functional, what is likely to happen? (a) The pancreatic enzymes and specially the trypsin and lipase will ... more effective. (d) Proteins will not be adequately hydrolysed by pepsin into proteoses and peptones.

Last Answer : (d) Proteins will not be adequately hydrolysed by pepsin into proteoses and peptones.

What is common among amylase, rennin and trypsin? (a) These are produced in stomach. (b) These act at a pH lower than 7. (c) These all are proteins. (d) These all are proteolytic enzymes.

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Last Answer : (c) These all are proteins.

Pick out the wrong statement. (A) Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat (B) Burning the fuel with theoretically required amount of pure oxygen results in attainment of maximum adiabatic flame temperature (C) Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature (D) Adiabatic flame temperatures of actual combustions are always less than the maximum values

Description : Pick out the wrong statement. (A) Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat (B) ... flame temperature (D) Adiabatic flame temperatures of actual combustions are always less than the maximum values

Last Answer : (C) Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature

Prosthetic groups differ from co-enzymes in that (a) they require metal ions for their activity (b) they (prosthetic groups) are tightly bound to apoenzymes (c) their association with apoenzymes is transient (d) they can serve as co-factors in a number of enzyme-catalyzed reactions.

Description : Prosthetic groups differ from co-enzymes in that (a) they require metal ions for their activity (b) they (prosthetic groups) are tightly bound to apoenzymes (c) their association with apoenzymes is transient (d) they can serve as co-factors in a number of enzyme-catalyzed reactions.

Last Answer : (b) they (prosthetic groups) are tightly bound to apoenzymes

Which characteristic of the Sun primarily determines the orbits of planets in our solar system A Large volume B Strong gravitational field C Mostly made of hydrogen D High surface temperatures?

Description : Which characteristic of the Sun primarily determines the orbits of planets in our solar system A Large volume B Strong gravitational field C Mostly made of hydrogen D High surface temperatures?

Last Answer : B (gravity)

For optimum vase life, most cut flowers should be stored at temperatures close to: a. 40 ºF b. 45 ºF c. 30 ºF d. 50 ºF

Description : For optimum vase life, most cut flowers should be stored at temperatures close to: a. 40 ºF b. 45 ºF c. 30 ºF d. 50 ºF

Last Answer : 40 ºF

Isoenzymes can be characterized by (A) Proteins lacking enzymatic activity that are necessary for the activation of enzymes (B) Proteolytic enzymes activated by hydrolysis (C) Enzymes with identical primary structure (D) Similar enzymes that catalyse different reaction

Description : Isoenzymes can be characterized by (A) Proteins lacking enzymatic activity that are necessary for the activation of enzymes (B) Proteolytic enzymes activated by hydrolysis (C) Enzymes with identical primary structure (D) Similar enzymes that catalyse different reaction

Last Answer : Answer : B

Satellite DNA is important because it (a) does not code for proteins and is same in all members of the population (b) codes for enzymes needed for DNA replication (c) codes for proteins needed in cell cycle (d) shows high degree of polymorphism in population and also the same degree of polymorphism in an individual, which is heritable from parents to children.

Description : Satellite DNA is important because it (a) does not code for proteins and is same in all members of the population (b) codes for enzymes needed for DNA replication (c) codes for proteins ... and also the same degree of polymorphism in an individual, which is heritable from parents to children.

Last Answer : (d) shows high degree of polymorphism in population and also the same degree of polymorphism in an individual, which is heritable from parents to children

The minimum energy required to allow a chemical reaction to proceed is termed as the 'threshold energy '. Chemical reactions with low activation energy are: (A) Always irreversible (B) Insensitive to temperature changes (C) Mostly irreversible (D) Highly temperature sensitive

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Last Answer : (B) Insensitive to temperature changes

Which of the following statements regarding mitochondrial membrane is not correct ? (a) The outer membrane resembles a sieve. (b) The outer membrane is permeable to all kinds of molecules. (c) The enzymes of the electron transfer chain are embedded in the outer membrane. (d) The inner membrane is highly convoluted forming a series of infoldings.

Description : Which of the following statements regarding mitochondrial membrane is not correct ? (a) The outer membrane resembles a sieve. (b) The outer membrane is permeable to all kinds of molecules. (c) ... in the outer membrane. (d) The inner membrane is highly convoluted forming a series of infoldings.

Last Answer : (c) The enzymes of the electron transfer chain are embedded in the outer membrane.

Copper is often used as an electrical conductor because it _______________. A. has high resistance at low temperatures B. has a highly polished surface C. is able to pass current with little opposition D. holds insulation together well

Description : Copper is often used as an electrical conductor because it _______________. A. has high resistance at low temperatures B. has a highly polished surface C. is able to pass current with little opposition D. holds insulation together well

Last Answer : Answer: C

Name the organelle that contains high levels of hydrolases and is responsible for digestion of proteins, sugars, nucleic acids and lipids.

Description : Name the organelle that contains high levels of hydrolases and is responsible for digestion of proteins, sugars, nucleic acids and lipids.

Last Answer : Lysosomes

The restriction enzymes are used in genetic engineering, because (a) they can cut DNA at specific base sequence (b) they are nucleases that cut DNA at variable sites (c) they can degrade harmful proteins (d) they can join different DNA fragments.

Description : The restriction enzymes are used in genetic engineering, because (a) they can cut DNA at specific base sequence (b) they are nucleases that cut DNA at variable sites (c) they can degrade harmful proteins (d) they can join different DNA fragments.

Last Answer : (a) they can cut DNA at specific base sequence

Melting temperature of DNA is the temperature at which (A) Solid DNA becomes liquid (B) Liquid DNA evaporates (C) DNA changes from double helix into supercoiled DNA (D) Native double helical DNA is denatured

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Last Answer : Answer : D

With regard to DNA molecules: a. they contain adenine, cytosine, guanine and uracil bases b. they can be detected with Western blotting c. they can be detected with Southern blotting d. they are denatured at temperature of 1000C

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Last Answer : they can be detected with Southern blotting

Which of the following statements is not correct? (a) Lysosomes are formed by the process of packaging in the endoplasmic reticulum. (b) Lysosomes have numerous hydrolytic enzymes. (c) The hydrolytic enzymes of lysosomes are active under acidic pH. (d) Lysosomes are membrane-bound structures.

Description : Which of the following statements is not correct? (a) Lysosomes are formed by the process of packaging in the endoplasmic reticulum. (b) Lysosomes have numerous hydrolytic enzymes. (c) The hydrolytic enzymes of lysosomes are active under acidic pH. (d) Lysosomes are membrane-bound structures.

Last Answer : (a) Lysosomes are formed by the process of packaging in the endoplasmic reticulum.