Tag: bio-chemistry

Questions Related to bio-chemistry

When liquids are heated, they turn into gases. The yellow egg yolk present inside the egg is a liquid but when it is heated, it changes into an omelet, which is solid. Why?

bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

  1. Sometimes, liquids turn into solids

  2. Omelet does not follow the above rule

  3. Strictly speaking, the rule does not apply to complex mixtures and egg yolk is a complex mixture

  4. None of the above

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Correct Option: C
Explanation:

The egg still contains more water than protein, but the water is now dispersed in the protein web so it can no longer flow together, turning the liquid egg into a semi-solid. This happens at around $145^{o}F$ for egg white and $150^{o}F$ for egg yolk. Continued heating causes more bonds to form, leaving less space for the water, that's why after heating the yolk converts in solid omelet.

The primary structure of proteins is associated with this:

bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

  1. amino acid sequence

  2. $\beta$ -pleated sheet structure

  3. conformation

  4. relative position of subunits

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Correct Option: A

The bonds responsible for the tertiary structure of proteins are:

bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

  1. hydrogen bonds

  2. Vander wall forces

  3. disulphide bonds

  4. All the above.

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Correct Option: A

$\alpha$ helix nature of proteins tell about the structure of proteins.

bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

  1. True

  2. False

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Correct Option: B
Explanation:

Given statement is false.

$'\alpha '$ helix structure of proteins tells about 'shape" of proteins and not structure.

Myoglobin can be analysed for its quaternary structure.

bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

  1. True

  2. False

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Correct Option: B
Explanation:

Myoglobin is a simple protein consisting of a single polypeptide. Since the quaternary structure is composed of an assembly of subunits of polypeptides, myoglobin does not have a quaternary structure. Due to the lack of multiple subunits, it has the highest level of structure as tertiary. Hemoglobin, on the other hand,  is composed of multiple polypeptide subunits, each capable of binding and transporting one molecule of oxygen in the blood, thus giving it a quaternary structure.

 Peptide linkages ($\displaystyle CONH$) are present in the primary structures of proteins while the secondary structures of proteins involve ______. 

bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

  1. Coordinate bonding

  2. Ionic bonding

  3. hydrogen bonding

  4. none

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Correct Option: C

The building block of proteins are:

bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

  1. $\alpha$-hydroxy acid

  2. $\alpha$-amino acid

  3. $\beta$- hydroxy acid

  4. $\beta$- amino acid

Show answer
Correct Option: B
Explanation:

The building block of proteins are $ \displaystyle \alpha-$amino acids.
On hydrolysis, proteins gives  $ \displaystyle \alpha-$amino acids.
 $ \displaystyle \alpha-$amino acids have structure  $ \displaystyle H _2N- \underset {  \displaystyle   { \underset {  \displaystyle  \text { R } }{ | } } }{CH }-COOH$
Proteins $ \displaystyle \xrightarrow {H _2O}n H _2N- \underset {  \displaystyle   { \underset {  \displaystyle  \text { R } }{ | } } }{CH }-COOH$
Proteins are polypeptides and contain peptide linkage ($ \displaystyle - \underset {  \displaystyle   { \underset {  \displaystyle  \text { O } }{ || } } }{C }-NH-$ linkage)