Biomolecules Overview Quiz

Biomolecules

Biomolecules are essential organic compounds that play a crucial role in the maintenance and metabolic processes of living organisms. They range from small molecules such as primary and secondary metabolites and hormones to large macromolecules like proteins, nucleic acids, carbohydrates, and lipids. Each of these classes of biomolecules has unique properties and functions within cells.

Carbohydrates

Carbohydrates, also known as saccharides, are polyhydroxy aldehydes or ketones or compounds that produce them on hydrolysis. They are the most abundant dietary source of energy and are structurally essential for many living organisms. Carbohydrates can be classified into three types based on the number of sugar units: monosaccharides (1 unit), oligosaccharides (2-10 units), and polysaccharides (more than 10 units). Cellulose, a polysaccharide, is an important structural fibre for plants, while starch is a storage carbohydrate in plants.

Proteins

Proteins are polymers of amino acids arranged in the form of polypeptide chains. They play both structural and dynamic roles in cells. Proteins make up about 50% of the cellular dry weight and have a complex structure, classified as primary, secondary, tertiary, and quaternary in some cases. Myosin, the protein that allows movement by contraction of muscles, is an example of a protein with a dynamic role. Most enzymes, which are proteinaceous in nature and catalyze chemical reactions, are another example of proteins with a structural and dynamic role.

Nucleic Acids

Nucleic acids are the genetic material found in the cell that carries all the hereditary information from parents to offspring. There are two types of nucleic acids: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is a double-stranded molecule, while most RNA molecules are single-stranded. The monomeric unit of nucleic acids is known as nucleotide, which is composed of a nitrogenous base, pentose sugar, and phosphate. DNA contains the nitrogenous bases adenine, guanine, cytosine, and thymine, while RNA contains adenine, guanine, cytosine, and uracil.

Lipids

Lipids are a diverse group of organic compounds that include fats, oils, waxes, and steroids. They serve as a source of stored energy and provide the building blocks for biological membranes, which separate cells from their environments and compartmentalize the cell interior. Lipids are usually hydrophobic, meaning they do not mix with water, and form membranes through a process called lipid bilayer formation, where two layers of phospholipid molecules form a barrier.

In conclusion, biomolecules are essential for life and have a wide range of functions, from providing energy and structural components to carrying genetic information and catalyzing chemical reactions. Understanding these molecules is crucial for understanding life at the cellular level.