What is the correct sequence of proteins to amino acids?

A. Proteins

B. Peptones

C. Simple peptides

D. Polypeptides

E. Amino acids

Choose the correct answer from the options given below:

A, B, D, C, E

The correct answer is option 1. A, B, D, C, E.

The breakdown of proteins into amino acids occurs through a series of steps, typically via enzymatic hydrolysis, where enzymes progressively cleave the protein's peptide bonds.

A. Proteins :

Proteins are large, complex molecules made up of one or more chains of amino acids arranged in a specific sequence. These chains are linked by peptide bonds, and proteins are often folded into specific three-dimensional structures, allowing them to perform various biological functions (e.g., enzymes, antibodies, hormones).

Proteins have primary (sequence of amino acids), secondary (alpha-helix and beta-sheet), tertiary (3D structure), and quaternary (multiple polypeptides) structures. During digestion or degradation, enzymes like proteases begin breaking down proteins into smaller fragments. The process typically begins in the stomach (e.g., with pepsin) and continues in the small intestine (e.g., with trypsin, chymotrypsin).

B. Peptones:

Peptones are partially hydrolyzed proteins. They are intermediate compounds formed when the protein structure begins to break down into smaller fragments.

When the peptide bonds of a protein are cleaved, but not completely broken down into smaller units, peptones are formed. Peptones still contain multiple amino acids linked together but are smaller than intact proteins. The action of enzymes like pepsin and trypsin hydrolyzes proteins into peptones during the initial stages of digestion. Peptones are a more manageable form for further enzymatic breakdown.

D. Polypeptides:

Polypeptides are long chains of amino acids that result from further breakdown of peptones. They are smaller than proteins but still consist of multiple amino acids linked together in a linear chain by peptide bonds.

Polypeptides are an essential intermediate in protein degradation. These chains are not fully folded like proteins but are still composed of several amino acids. Enzymes like trypsin, chymotrypsin, and elastase work to break peptones into polypeptides in the small intestine.

C. Simple Peptides:

Simple peptides are smaller fragments that consist of just a few amino acids. They are short chains of amino acids, often referred to as dipeptides (two amino acids) or tripeptides (three amino acids).

Simple peptides are formed when polypeptides are cleaved into smaller units. These are simpler, shorter chains that can be more easily broken down into individual amino acids. Peptidases (also known as exopeptidases or dipeptidases) act on polypeptides to cleave them into simple peptides.

E. Amino Acids:

Amino acids are the fundamental building blocks of proteins. They are small organic molecules that contain an amino group \((-NH_2)\), a carboxyl group \((-COOH)\), and a unique side chain (R group).

Amino acids are the final product of protein digestion. Once proteins are fully broken down into amino acids, they can be absorbed into the bloodstream and used by the body for various functions, such as building new proteins, repairing tissues, or as an energy source. Peptidases and aminopeptidases act on simple peptides to finally cleave them into individual amino acids, which are then ready for absorption

Correct Sequence:  A → B → D → C → E

This sequence (Proteins → Peptones → Polypeptides → Simple Peptides → Amino Acids) corresponds to option 1.A, B, D, C, E