What are essential and non-essential amino acids? Give two examples of each type.

\\(\text {Essential Amino Acids}:\\) Amino acids which can't be created in our body but can only be received from proper food or diet are called \\(\text {Essential Amino Acids}\\). Examples- Histidine, Isoleucine, Lysine.\\(\text {Non- essential amino acids}:\\) Amino acids which can be created in our body itself are \\(\text {Non- essential amino acids}\\). Examples-alanine, arginine, asparagine, aspartic acid. Examples- Histidine, Isoleucine, Lysine.

Which of the following amino acid is neutral ?

Neutral Amino acids: Glycine, Alanine, leucine, Isoleucine, valine, phenylalanine, Proline, methionine, serine, threonine, tyrosine, cysteine, glutamine, asparagine, tryptophan.Acidic amino acids: Aspartic acid, glutamic acidBasic amino acids: Lysine, histidine, ArginineTherefore, option B is correct

Define the following as related to proteins :(i) Peptide linkage (ii) Primary structure(iii) Denaturation

I) Peptide linkage is the peptide bond formed between the amino acids. It is a covalent bond formed between amino group of one molecule and carboxylic acid group of another molecule.II)The primary structure of a peptide or protein is the linear sequence of its amino acid structural units. The primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end.(III) The process in which proteins or nucleic acids lose the quaternary structure, tertiary structure and secondary structure which is present in their native state known as denaturation. by application of some external stress or compound such as a strong acid or base, a concentrated inorganic salt, an organic sol.

Recognise the figure and find out the correct matching.

A) Correct option C B) Explanation for the correct option: Figure A shows the secondary structure and B represented the tertiary structure.The secondary structure of the protein, which has hydrogen bonds in addition to the peptide bonds that provide stability to the protein.The tertiary structure is formed when secondary proteins fold more than once.

The melting points and solubility in water of amino acids are generally higher than of corresponding halo acids.

Like ionic compounds, amino acids have a strong electrostatic attraction when present in zwitterion. Because of this, they have a melting point and solubility in higher than the corresponding haloacids.

What is a peptide bond?

A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino acid group of the other molecule, resulting into the formation of an amide group along with a molecule of water. The reaction is known as dehydration synthesis/ condensation reaction and the resulting \\( CO-NH \\) bond is known as a peptide bond.

Write short notes on: Zwitter ion.

A zwitterion is a molecule that has at least two functional groups: one having a positive charge and the other having a negative charge, with an overall charge of zero. Zwitterions can form from other molecules called ampholytes, or amphoteric compounds and can act as both an acid and a base.Zwitterions are polyelectrolytes that contain both positively and negatively charged groups, and the overall charges are neutral.

Amino acids generally exist in the form of Zwitterions. This means they contain :

Basic \\({-COO}^{-}\\) group and acidic \\(-\overset {+}{N}{H}_{3}\\) groupA zwitterion is a compound with no overall electrical charge, but which contains separate parts which are positively and negatively charged. In aqueous solution, the carboxyl group can lose a proton (becomes basic group) and amino group can accept a proton (becomes acidic) giving rise to the dipolar ion known as Zwitterions.\\(\underset{\text{amino acid}}{{H}_{2}N-CH(R)-COOH} \rightleftharpoons \underset{Zwitterion}{{H}_{3}\overset{+}{N}-CH(R)-{COO}^{-}}\\)

Define peptide linkage.

Peptide linkage is a peptide bond which is formed between two amino acid[- CO- NH-]\\(H_ 2N-CH\boxed { -CO-NH- } -CH_3\\)

Amino acids | Definition, Examples, Diagrams

definition

Definition and examples of alpha amino acid

Amino acids are the basic building units of proteins.Their molecule posses both an amino group as well as a carboxylic group. The amino acids having amino and carboxyl group attached to the same carbon, i.e., alpha-carbon atom is called as alpha-amino acids.
Example: Glycine , Alanine etc.

diagram

Rules for nomenclature of amino acid

Amino acids are generally known by their common names. In IUPAC system each amino acid has been given standard abbreviation or a code which usually consists of first three letters of the common name. For example, glycine is given the code ala. Sometimes one letter symbol is also used. For example, glycine is represented by G and alanine by A.

definition

classification of amino acids

1. Neutral amino acid
2. Acidic amino acid
3. Basic amino acid

diagram

Neutral amino acids

The amino acid containing one -

N H_{2}

and one COOH groups, are called neutral amino acids.
Example: Alanine.

diagram

Acidic amino acids

The amino acids containing two -COOH groups and one -

N H_{2}

group are called acidic amino acids.For example, aspartic acid, glutomic acids.

diagram

Basic amino acids

The amino acids containing two

- N H_{2}

groups and one

- C O O H

group are called basic amino acids. Some examples of basic amino acids are lysine, arginine.

diagram

Essential and non-essential amino acids

The amino acids which human body can not synthesize and must be supplied in the diet are called essential amino acids. Example, Valine, leucine etc.
The amino acids which are synthesized by the human body are termed as non-essential amino acids. Example, Glycine.

diagram

Physical properties of alpha-amino acids

The important physical properties of alpha-amino acids are as follows.
1) Amino acids are usually colorless, crystalline solids with high melting point
2) They are soluble in water. The aqueous solution is neutral and shows amphoteric behavior

diagram

Chemical properties of amino acids

Alpha-amino acid contain both amino as well as acidic group .They form salts with acids as well as with base.

diagram

Zwitter ion

Zwitter ion prepared by loss of proton by acidic carboxyl group which is taken up by the basic amino group in alpha-amino acids. Zwitter ion is neutral but contains both positive and negative charges. Due to its dipolar nature it is referred to as a dipolar ion.

example

Define and give examples of peptide bond

The bond formed by condensation of amino acid molecules is called as peptide bond or peptide linkage.

Amino acids

definition

Definition and examples of alpha amino acid

diagram

Rules for nomenclature of amino acid

definition

classification of amino acids

diagram

Neutral amino acids

diagram

Acidic amino acids

diagram

Basic amino acids

diagram

Essential and non-essential amino acids

diagram

Physical properties of alpha-amino acids

diagram

Chemical properties of amino acids

diagram

Zwitter ion

example

Define and give examples of peptide bond

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Structure of Proteins

Quick Summary With Stories

Classification of Amino Acids

Chemical Properties and Classification of amino acids

What are essential and non-essential amino acids? Give two examples of each type.

Which of the following amino acid is neutral ?

Define the following as related to proteins :
(i) Peptide linkage
(ii) Primary structure
(iii) Denaturation

Recognise the figure and find out the correct matching.

The melting points and solubility in water of amino acids are generally higher than of corresponding halo acids.

What is a peptide bond?

Which of the following compounds can form a zwitter ion?

Write short notes on: Zwitter ion.

Amino acids generally exist in the form of Zwitterions. This means they contain :

Define peptide linkage.