Atoms are the basic units of matter. They are composed of smaller units known as subatomic particles, specifically protons, neutrons, and electrons, which determine the chemical properties and identity of the element.

Glycine is the simplest amino acid in the proteinogenic set. Its side chain (R group) consists of a single hydrogen atom, making it the only achiral amino acid among the twenty standard amino acids.

Vitamins are categorized based on their solubility. Vitamins A, D, E, and K are fat-soluble, meaning they are stored in the body's fatty tissues. In contrast, Vitamin B complex and Vitamin C are water-soluble and are not stored in the body in significant amounts.

Biochemistry is the scientific discipline that explores the chemical processes and substances that occur within living organisms. It bridges biology and chemistry by examining how molecules such as proteins, nucleic acids, lipids, and carbohydrates interact to sustain life, regulate cellular activity, and facilitate metabolic pathways essential for survival.

While only 20 amino acids are commonly encoded by the genetic code to build proteins, a much larger variety of amino acids exists in nature. Scientists have identified over 170 different amino acids in various biological cells and tissues, including non-proteinogenic amino acids that serve as metabolic intermediates or specialized signaling molecules within diverse organisms.

Thiamine, also known as Vitamin B1, is a water-soluble vitamin that plays a critical role in energy metabolism. It acts as a coenzyme in the decarboxylation of alpha-keto acids, which is essential for the conversion of carbohydrates into energy. Deficiency in thiamine can lead to conditions such as beriberi, which affects the cardiovascular and nervous systems.

Nucleoproteins are complexes consisting of nucleic acids (DNA or RNA) bound to proteins. These structures are fundamental to the storage and transmission of genetic information, as DNA serves as the primary hereditary material in living organisms, often organized into chromatin or viral particles.

Biological elements, such as carbon, hydrogen, oxygen, and nitrogen, form covalent bonds by sharing electrons. These interactions result in the creation of molecules essential for life, commonly referred to as biomolecules, which include carbohydrates, lipids, proteins, and nucleic acids. Both terms describe the fundamental chemical building blocks that sustain biological processes and cellular structures within living organisms.

Proteins are large, complex macromolecules composed of long chains of amino acids linked by peptide bonds. During digestion, enzymes such as pepsin and trypsin hydrolyze these peptide bonds, breaking the protein chains down into their constituent amino acids, which can then be absorbed into the bloodstream and utilized by cells for protein synthesis.

Oxygen is the most abundant element in the human body by mass, primarily because it is a major component of water, which makes up about 60-70% of the body's total weight. Additionally, oxygen is found in almost all organic molecules, including proteins, carbohydrates, and lipids, contributing to approximately 65% of the total human body mass.