Proteins

Q.

How would you describe the steps in protein synthesis?

Q.

What is the denaturation and renaturation of proteins?

Q.

What is “semi-permeable membrane”?

Q.

Differentiate between intrinsic and extrinsic protein

Q.

In fibrous proteins, polypeptide chains are held together by ........... .
(a) van der Waals forces (b) disulphide linkage
(c) electrostatic forces of attraction (d) hydrogen bonds

Q.

Give an example of fibrous and globular protein.

Q.

Proteins can be classified into two types on the basis of their molecular shape, i.e., fibrous proteins and globular proteins. Examples of globular proteins are
(a) insulin (b) Keratin (c) albumin (d) myosin

Q. Energy is stored in our body most commonly in the form of

1. ATP
2. Fats
3. Carbohydrates
4. ADP

Q. How many fragments will be generated on digestion of a closed circular DNA molecule with a restriction enzyme having six recognition sites on true DNA ?

Q.

What is cellulose? Write short notes on it?

Q. The protein present in the hair is:

1. lysine
2. myosine
3. keratin
4. alanine

Q.

Coagulation of egg white on boiling is an example of denaturation of protein. Explain it in terms of structural changes.

Q.

Which of the following do not cause denaturation of proteins

1. Heating proteins
2. Adding acid to proteins
3. Adding water to proteins
4. Adding detergent to proteins

Q. The following molecule is fluorometholone, a steroidal anti-inflammatory agent. How many stereogenic centers does it contain?

Q.

Differentiate between globular and fibrous proteins.

Q. What are enzyme inhibitors? Classify them on the basis of their mode of attachments on the active site of enzymes. With the help of diagrams explain how do inhibitors inhibit the enzymatic activity.

Q. Which of the following statements is incorrect with respect to starch?

1. It is a reducing carbohydrate
2. It is a polymer of α-D-glucose
3. It consists of branched chains
4. It consists of amylose and amylopectin

Q.

In a protein molecule various amino acids are linked together by

1. peptide bond

2. dative bond

3. $\alpha$ glycosidic bond

4. $\beta$ glycosidic bond

Q.

The flocculation value of $\mathrm{HCl}$ for ${\mathrm{As}}_2{\mathrm{S}}_3$sol is$30\mathrm{m}\mathrm{mol}{\mathrm{L}}^{-1}$. It ${\mathrm{H}}_2{\mathrm{SO}}_4$ is used for the flocculation of arsenic sulfide, the amount, in grams, of ${\mathrm{H}}_2{\mathrm{SO}}_4$ in$250\mathrm{mL}$ required for the above purpose is

Q.

QUESTION 14.12(i)

Define the following as related to proteins.
Peptide linkage

Define the following as related to proteins.
Primary structure

Define the following as related to proteins.
Denaturation.

Q. Identify the correct match.
(correct answer +2, wrong answer -0.5)

1. Keratin-fibrous protein; found in muscles
2. Insulin-fibrous protein; found in pancreas
3. Keratin-globular protein; found in silk
4. Myosin-fibrous protein; found in muscles

Q.

In which of the given processes, do both the strands of nucleic acid act as templates?

1. Replication

2. Translation

3. Transcription

4. All of the above

Q.

Proteins are found to have two different types of secondary structures viz $\alpha -$ helix and $\beta -$ pleated sheet structure. $\alpha -$ helix structure of protein is stabilised by
(a) peptide bonds (b) van der Waals, forces
(c) hydrogen bonds (d) dipole-dipole interactions

Q. Given below are two statements A and B. Choose the correct answer related to the statements. Statement A: Amino acids are amphoteric in their function Statement B: All amino acids are necessary for our body

1. Statement A is correct but statement B is wrong
2. Both the statements A and B are correct
3. Statement A is wrong but statement B is correct
4. Both the statements A and B are wrong

Q.

Structures of glycine and alanine are given below. Show the peptide linkage in glycylalanine.
$\underset{\left(Glycince\right)}{H_{2}N-C{H}_2-COOH;H_{2}N-}\underset{\left(Alanine\right)}{\underset{C{H}_3}{\underset{|}{CH}}}$-COOH

Q.

During curdling of milk, what happens to sugar present in it?

Q. Choose the correct statement(s):

Q.

Each polypeptide in a protein has amino acids linked with each other in a specific sequence. This sequence of amino acids is said to be .............. .
(a) primary structure of proteins (b) secondary structure of proteins
(c) tertiary structure of proteins (d) quaternary structure of proteins

Q.

Globular proteins can be found in

1. Eggs

2. Blood

3. Muscles

4. All of the above

Q.

The bicyclic and heterocyclic compound among the following

1. 5 - methyl uracil
2. 2 - Amino - 6 - oxo purine
3. Cytosine
4. Glutamic acid