Nucleic Acids and so on....

Nucleic Acids

Nucleic acids form from polymers of nucleotides, molecules composed of a phosphate group, a five-carbon sugar, and a nitrogenous base. Five different nitrogenous bases exist:

Adenine
Guanine
Cytosine
Thymine ( only in DNA)
Uracil ( only in RNA)
DNA and RNA are nucleic acids that function in protein synthesis and the storage and transmission of genetic information.

Proteins

Proteins consist of one or more polypeptides, polymers of amino acids folded into complex three-dimensional shapes. An amino acid is a small molecule made up of a central carbon atom, an amino group, a carboxyl group, a hydrogen atom, and a functional group labeled “R.” Twenty different amino acids exist, each formed with a different R group. Polypeptides form when amino acids bond together in long chains. The twenty different amino acids can produce a diverse range of proteins, including enzymes, hormones, cell receptors, antibodies, transport proteins, storage proteins, motor proteins, and structural proteins, which perform a wide range of vital tasks in organisms.

All proteins have either three or four structural levels:

Primary structure refers to the sequence of amino acids that form the polypeptides.
Hydrogen bonds in single groups in a polypeptide chain result in a folded region referred to as the secondary structure. Secondary structures include helices (coils) and sheets (pleated folds).
The tertiary structure describes the folding of an entire polypeptide chain. Interactions between the R groups of the polypeptide chain determine the overall shape of the tertiary structure.
Interaction between two or more polypeptides forms the quaternary structure. Since some proteins consist of a single polypeptide, not all proteins exhibit quaternary structure


Protein Structure
Carbohydrates


Carbohydrates include both monosaccharides (also called simple sugars or simple carbohydrates) and polysaccharides (also called complex carbohydrates). Monosaccharides and polysaccharides perform different functions in organisms:

Monosaccharides, which include glucose, fructose, and lactose, provide cells with energy.
Polysaccharides, which include glycogen, starch, and cellulose, store energy and provide structural support to an organism.
Lipids

Unlike the other macromolecules, lipids are not composed of repeated monomers and therefore are not true polymers. Lipids exhibit a range of structural diversity, but all are nonpolar and therefore insoluble in water. Lipids include the following molecules:

Fats: store energy for future use in biological functions
Phospholipids: make up the cell membrane
Steroids: act as chemical messengers in an organism