Introduction to various biological molecules

Essay by lonelyblueHigh School, 10th grade September 2006

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1. Protein


There are a total of 4 types of protein structures.

Primary protein structure

o Chain of amino acid

Secondary protein structure

o Occurs when the sequence of amino acids are linked together by hydrogen bonds

Tertiary protein structure

o Occurs when certain attraction are present between alpha helices and pleated sheets

Quaternary protein structure

o Protein consisting of more than one amino acid chain.


Protein essential to the cell. They are involved in practically every function performed by a cell. Life, chemically speaking, is nothing but the function of proteins although the information to make a unique protein resides in DNA. Functional proteins are those molecules that do everything that happens within us.

2. Fats


Any fat molecule, also known as a fatty acid, has:

Chain of hydrocarbons, attached to each other in either a single- or double-bond (a hydrocarbon consists of a carbon atom with at least 1 hydrogen atom "bonded" or "connected" to it)

Carboxyl group at one end of the chain (a carboxyl group consists of a carbon atom, an oxygen atom, and an oxygen-hydrogen or hydroxide group).

There are 4 different types of fats:

Saturated fat

o Saturated fat has no double bond between any hydrocarbon chain and therefore allows the fat molecule to be 'saturated' with as much hydrogen as it can hold.

Unsaturated fat

o A fat is defined as unsaturated if it has at least one double-bond in the hydrocarbon chain. This double-bond results in less hydrogen in the chain than if there were no double-bonds. Hence, the chain is unsaturated with respect to the maximum hydrogen that could be present.

o There are 2 types of unsaturated fats

Mono-unsaturated fats

They contain a single double bond chain so it does not contain much hydrogen.

Poly-unsaturated fats