Organic Chemistry: Protein

Select the correct function/s of protein.

• Reserve energy of animals and plants.

• The skeletal structure of plants.

• Part of transport in human body.

• Act as catalysts in chemical reactions.

• Can protect an organism against disease.

Select the correct statement/s about amino acids.

• Amino acids are compounds that contain an amino group alpha to a carboxyl group.

• Each amino acid has an acid (a -COOH group) and a base

  (an -NH₂ group) that undergo an acid–base reaction.

• the vast majority of naturally occurring amino acids have the d-configuration at the a-carbon.

• All protein-derived amino acids are chiral.

• Amino acids are weak polyprotic acids.

Select the correct statement/s about polypeptide or protein?

• A peptide bond is the special name given to the amide

  bond formed between a-amino acids.

• The primary (1°) structure of a polypeptide or protein refers to the sequence of amino acids in its polypeptide chain.

• A-helix and B-pleated sheet are types of tertiary structure.

• Tertiary (3°) structure refers to the overall folding pattern and arrangement in space of all atoms in a single polypeptide chain.

• Secondary (2°) structure is the arrangement of individual polypeptide chains into a non-covalently bonded aggregate.

Answer true or false to the following statement. The isoelectric point of an amino acid is the pH at which the majority of molecules in solution have a net charge of -1.

• True.

• False.

Disulfide bonds play an important role in maintaining tertiary structure. What kind of amino acid that form disulfide bond?

• Phenylalanine

• Valine

• Histidine

• Cysteine

• Tyrosine

Protein chain stabilized through chemical bonding and interaction. Which can be categorized as stabilizing factors in a protein?

• Hydrogen bonding.

• Salt bridges.

• Hydrophobic interactions.

• Disulfide bonds.

• Double bonds.

Of the 20 protein-derived amino acids, what amino acids contain aromatic rings?

• Phenylalanine.

• Serine

• Histidine.

• Methionine.

• Tyrosine.

Answer true or false to the following statement. Electrophoresis, a process of separating compounds on the basis of their electric charges, is used to create a synthetic protein.

• True.

• False.

The structure of proteins can be changed by environmental factors such as ....

• Basic.

• Temperature.

• Radiation.

• Salt concentrations.

• Physical intervention.

What gives a protein its unique shape?

• The sequence of amino acids in its polypeptide chain.

• The folding due to the sequence of amnio acids in the polypeptide chain.

• The interactions between the 'R' groups.

• All of these.

• None of these.