Introduction to Proteins, Nucleic Acids, and ATP

Proteins: Structure and Functions

Proteins are long chains of amino acids linked by peptide bonds, characterized by a specific order of 20 unique amino acids. Their structure is defined by four levels: primary (sequence), secondary (alpha helices and beta sheets), tertiary (globular folding), and quaternary (multiple polypeptide interactions). Proteins are classified as fibrous (structural, like collagen) or globular (functional, like enzymes, antibodies, and hormones). They are sensitive to pH and temperature, and when these conditions fluctuate, proteins can 'denature,' losing their specific shape and function.

Enzyme Mechanics

Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required. They are highly specific, binding to particular substrates at their active sites to form products without being consumed in the process. Enzyme activity is strictly dependent on maintaining their correct shape.

Nucleic Acids: DNA and RNA

Nucleic acids consist of nucleotides containing a nitrogenous base, a pentose sugar, and a phosphate group. DNA, which forms a double helix, serves as the genetic blueprint and is located in the nucleus. RNA is single-stranded, contains uracil instead of thymine, and acts as a messenger to synthesize proteins in the cytosol.

ATP: Energy Currency

Adenosine Triphosphate (ATP) is a nucleotide with three phosphate groups. It functions as the primary energy carrier in the body. Energy is released when a phosphate group is removed, converting ATP into ADP or AMP, which then powers processes like transport, muscle contraction, and chemical reactions.