BIOCHEMISTRY

Biochemistry of Macromolecules & Metabolic Pathways

Biochemistry of Macromolecules & Metabolic Pathways

Introduction

Metabolic pathway is a succession of reaction chemistry, in which the product of one reaction is the substrate of another. The reaction pathways are usually catalyzed by enzymes, and are subject to strict controls. In the whole body metabolic reactions are regulated by hormones (Clausen, 1988, pp. 22).

Types of metabolic pathways

In the cells of organisms living there are many metabolic pathways:

converting some of these compounds more complex to a less complex form of useful energy while metabolically ; energy supply paths is defined as the catabolic pathways

sets of reactions that lead to the production of more complex chemical compounds simultaneously requiring supply of energy is defined as anabolic pathways

some metabolic pathways can lead to formation of molecules simpler or more complex compounds according to the energy state of the cell;

Task 1)

Fatty Acid and its structure

A fatty acid is a bio-molecule nature lipid consists of a long chain linear hydrocarbon, of different length or number of carbon atoms, in whose end there is a carboxyl group (are organic acids long chain). Each atom of carbon is attached to the preceding and following through a covalent single or double. The atom of its free end has left three links that are occupied by atoms of hydrogen (H 3 C-). Other free atoms have two links, which are also occupied by hydrogen atoms (...-CH 2-CH 2-CH 2 - ...). At the other end of the molecule is the carboxyl group (-COOH) that is combined with one of the hydroxyl groups (-OH) of glycerol or propanetriol, reacting with it. The carboxyl group has character acid and the hydroxyl group has character basic (or alkaline) (Cantor, 1980, pp. 89).

In general (although they may not), we can write a fatty acid R-generic and COOH , wherein R is the hydrocarbon chain that identifies the particular acid.

Fatty acids form part of the phospholipids and glycolipids , molecules constituting the lipid bi-layer of all cell membranes . In mammals, including humans, mostly fatty acids are in the form of triglycerides, wherein the ends molecules carboxylic (-COOH) of three fatty acids are esterifies with each of the hydroxyl groups (-OH) of glycerol (glycerin, propanetriol) triglycerides are stored in adipose tissue (fat).

Chemical structure

Fatty acids consist of a alkyl chain with a group carboxyl (-COOH) terminal, the basic formula of a molecule is completely saturated CH 3 - (CH 2) n-COOH. The fatty acids of mammals have relatively simple structures, but other organisms can be very complex, with rings cyclopropane or heavy branches.

Molecule stearic acid a saturated fatty acid, represented schematically.

The same molecule with the group carboxyl dissociated.

Are common unsaturated fatty acid (double bonds), usually of cis configuration, when more than one double bond per molecule, are always separated by a group methylene (-CH 2 -). Common fatty acids in living organisms have an even number of atoms of carbon, although some organisms synthesize fatty acids with an odd number of carbons. Some animals, including humans, also produce branched fatty acids with one or more groups methyl (-CH 3) along the chain, such as the structures of echolocation of cetaceans in ...