Tag: biomolecules: chemical constituents of living cells

Questions Related to biomolecules: chemical constituents of living cells

Biocatalysts were found accidently in Yeast extract by

properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. Sumner

  2. Kuhne

  3. Buchner

  4. Pasteur

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Correct Option: C
Explanation:

Biocatalysts were found accidentally in yeast extract by Buchner in 1897. He prepared a yeast extract and added sugar solution to it. After sometime he noticed the alcohol formation in the extract which was a sign of fermentation which took in presence of enzyme. Later on, Sumner crystallized an enzyme known as urease and reported that all enzymes are protein.

So, the correct answer is option C.

Enzyme action comes to a stop when hydration decreases in maturing seeds to

properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. $50 - 60$%

  2. $30 - 45$%

  3. $25 - 30$%

  4. $10 - 20$%

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Correct Option: D

The action of lysozyme is

properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. Physiological

  2. Anatomical

  3. Morphological

  4. None of the above

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Correct Option: A
Explanation:

Lysozyme are also reffered as muramidase. They are glycoside hydrolases. They catalyzes hydorlysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetly-D-glucosamine residues in peptidoglycan thus they can dissolve bacterial cell wall. It is present  in a number of secretions, such as tears, saliva, human milk and mucus. So, its function is physiological.
Thus, the correct answer is option (A).

Metabolic processes in living organisms are catalyzed by

properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. Enzymes

  2. Nucleotides

  3. Nucleosides

  4. Lipids

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Correct Option: A
Explanation:

Enzymes are the biomacromolecules that catalyze metabolic processes in living organisms. 

So, the correct option is 'Enzymes'. 

Enzymes which transfer electrons are

properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. Hydrolyses

  2. Hydrogenases

  3. Proteases

  4. Transaminases

Show answer
Correct Option: B
Explanation:
Enzymes which helps in the transfer of electrons are known as hydrogenases. It catalyzes the reversible oxidation of hydrogen to protons by the loss of electrons. The electron acceptors like oxygen are reduced in this particular reaction while electron donors like ferredoxin are oxidized.
Hydrolyses are the enzyme which catalyzes the splitting of compounds by addition of water.
Proteases hydrolyze the peptide bond.
Transaminase catalyzes aminotransferase reaction between an amino acid and a α-keto acid.
So, the correct answer is option B.

Which one of the following enzymes is NOT made up of polypeptides?

properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. Ligase

  2. Ribosome

  3. Lysozome

  4. Chemotropism

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Correct Option: A

Select the correct option: 

Enzymes catalyze the biochemical reactions by .......... the activation energy.

properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. lowering

  2. increasing

  3. unaltering

  4. either (a) or (b)

Show answer
Correct Option: A
Explanation:

Enzymes are macromolecular biological catalysts. which accelerates chemical reactions. Catalysts lower the activation energy (energy required to start a reaction.) for reactions. The lower the activation energy for a reaction, the faster the rate.

So, the correct answer is 'lowering'.

Enzymes that catalyse removal of groups from substrates by mechanisms other than hydrolysis, and addition of groups to double bonds, are called
properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. Ligase

  2. Lyase

  3. Hydrolase

  4. Dehydrogenase

Show answer
Correct Option: B
Explanation:

Lyases enzymes catalyse the breakage of specific covalent bonds and removal of group with out hydrolysis producing double bonds or removal of double bonds by adding group,e.g., histidine decarboxylase that splits $C-C$ bond of histidine,forming $CO _2$ and histamine.

${\overset{X}{\overset{|}C}}-{\overset{Y}{\overset{|}C}} \xrightarrow{lyase}X-Y+C=C$

Relationship between genes and enzymes was discovered by

properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. Waldeyer

  2. W. Johannsen

  3. Bridges

  4. Beadle and tatum

Show answer
Correct Option: D
Explanation:

Sir Archibald Garrod proposed that one enzyme is encoded by one gene. This hypothesis called One gene One enzyme hypothesis, was experimentally proved by Beadle and Tatum by using bread mould Neurospora. Beadle and Tatum showed bread mould mutants that were unable to make specific amino acids. In each one, a mutation had disrupted an enzyme needed to build a certain amino acid. This was caused due to specific gene mutation.

Hence, the correct answer is 'Beadle and Tatum'

The hydrolytic enzymes acting at low pH are

properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

  1. $\alpha$-amylases

  2. Hydrolases

  3. Proteases

  4. Pyrimidases

Show answer
Correct Option: C
Explanation:

A protease (also called peptidase or proteinase) is any enzyme that performs proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein. Proteases may be classified by the optimal pH in which they are active: acid proteases or neutral proteases or basic proteases.