BIOCHEMISTRY

Biochemistry

Biochemistry

Carbohydrates, Proteins and Lipids

Molecular Structures

Carbohydrates

Carbohydrates are basic organic compounds containing three core elements: carbon, oxygen, and hydrogen. Also known as saccharides, these are generally divided into four primary groups: monosaccharides, polysaccharides, oligosaccharides and disaccharides. The general formula for all carbohydrates is CH2O. Carbohydrates are mainly divided into two basic structural forms: the chain structure, and the ring structure. For instance, glucose exists in both ring-like and chain structures (Burke & Dennis 2009, 57).

Glucose: (a) Chain Structure; (b) Ring Structure

Proteins

Proteins are biological combinations of molecules composed primarily of amino acids. The structure of proteins can be divided into four main categories on the basis of the sequence of amino acid linkage: primary, secondary, tertiary and quaternary. Change from one structure to another is possible through the performance of functions. These structures are frequently referred to as 'conformations', which may be ionic, hydrophobic, hydrogen bonding based, or Van-der-Waals force based.

Peptide bonds

Lipids

Lipids are organic molecules that are usually insoluble in water and other polar solvents. Some molecular structures are slightly water soluble. The structures are dominated by carbon and hydrogen elements, leaving little room for oxygen to form bonds. 16 to 18 C-H bonds are an average for a lipid structure. Examples of lipids include fats, steroids and phospholipids (Hengartner 2000, 772).

Lipid Structure

Functions

Carbohydrates

Carbohydrates serve several important functions, some of which are listed below:

They serve as important biological fuels for the human body, as they are primarily composed of sugars.

They serve as the basic fuel component required for metabolic activities.

They form as basic constituent parts in the various frameworks in certain micro organisms.

They also perform the basic function of an anticoagulant, which is to avoid intravascular clotting.

Proteins

The main functions of proteins are as follows:

They serve as the main building blocks in the human body and are abundantly present in pulses and whole grain cereals;

They ensure the regulation of various processes in the human body, such as maintaining water balance and regulating osmotic pressure;

They serve as a staple form of diet as they are richly present in mother's milk as well;

They are involved in the repairing and build-up of tissues in living organisms.

Lipids

Lipids are involved in many important bioorganic functions, such as the following:

They act as a source for the dissolving of other nutrients;

They assist in the storage of energy;

They control and dilute various chemical reactions within living organisms.

They help in maintaining the inner body temperature.

Polymers

Polymers are combinations of chemical compounds, which are produced naturally as well as artificially.

Synthesis

Formation of polymers takes place through a process known as polymerization. Certain important compounds are also lost during this process. Synthesis can take place biologically as well as within a laboratory. Apart from that, natural polymers can also be modified through oxidation processes. Polysaccharides, polynucleotides and polypeptides are the main categories of biopolymers.

Decomposition

The breakdown of polymers takes place through a process known as hydrolysis, in which chemical compounds are broken down through the usage of water. A number of enzymes are also utilized within the process, including glucose. The decomposition of polysaccharides translates into their transformation to oligosaccharides, ...