Carbohydrates are chemical molecules composed of carbon, hydrogen, and oxygen, often in
a 1:2:1 ratio. They consist of monosaccharides like glucose, disaccharides like sucrose, and
polysaccharides like starch and cellulose. Monosaccharides and disaccharides dissolve
quickly in water because their hydroxyl groups establish hydrogen bonds with water
molecules. Polysaccharides vary in solubility depending on their structure. Chemically,
carbohydrates can engage in oxidation-reduction reactions and generate glycosidic bonds
that link sugar units together. (Facciotti, 2021)
Carbohydrates break down through hydrolysis, where water splits them into smaller units by
breaking the glycosidic bonds. This process is essential for digestion, converting starch into
glucose for energy. Simple carbohydrates like monosaccharides and disaccharides are
crystalline solids that dissolve easily in water due to their hydroxyl groups. This makes them
easy for the body to absorb and use. Polysaccharides, like starch and glycogen, can dissolve
to form gels or pastes, while cellulose is insoluble due to strong bonds, providing structural
support in plant cell walls. Hydrolysis is crucial for converting complex carbohydrates into
usable energy. (Holesh, Martin and Aslam, 2023)
Lipids are hydrophobic and insoluble in water but soluble in nonpolar solvents like
chloroform. They can be solids like fats or liquids like oils at room temperature. Chemically,
lipids can undergo hydrolysis to break down into glycerol and fatty acids and participate in
reactions like hydrogenation and oxidation. (Ahmed, Ahmed and Shah, 2023)
Proteins are made of amino acids linked by peptide bonds, forming complex structures with
four levels: primary (sequence of amino acids), secondary (α-helices and β-sheets), tertiary
(3D shape), and quaternary (multiple polypeptides). (Khan Academy, 2015) They are
generally soluble in water and can denature at high temperatures or extreme pH levels.
Chemically, proteins can act as enzymes, catalysing reactions. Their physical properties, such
as solubility and stability, depend on their structure and function, making them versatile in
roles like catalysis, transport, and structural support. (Longo, 1998)
Nucleic acids, DNA and RNA, are polymers of nucleotides. Each nucleotide has a nitrogenous
base (adenine, thymine, cytosine, guanine for DNA and uracil replaces thymine in RNA), a
five-carbon sugar, a deoxyribose in DNA, and a ribose in RNA, and a phosphate group. DNA is
typically double-stranded, forming a stable double helix, while RNA is usually single-
stranded. Nucleic acids are highly charged and soluble in water due to their phosphate
backbone. They play critical roles in genetic information storage, replication, and protein
synthesis. (Blanco and Blanco, 2022)
Enzyme activity is influenced by factors such as temperature, pH, substrate concentration,
and the presence of inhibitors or activators. Enzymes work best within specific temperature
and pH ranges; deviations can denature them and reduce activity. For DNA extraction,
enzymes like proteases need the right temperature and pH to break down proteins