PP: Biomolecules

There are four main types of biomolecules: carbohydrates, proteins, lipids, and nucleic acids. These biomolecules make up the cells that make up organisms and are responsible for the mechanisms within the body. Carbohydrates are composed of carbons, hydrogens, and oxygens. Monosaccharides bond to form oligosaccharides that can be bound to cell surface proteins to aid in cell signaling. Proteins are made up of amino acids, which are composed of a central carbon bound to an amino group, a carboxyl group, and a variable "R" group. The R group can be nonpolar, polar without charge, negatively charged, or positively charged, and the polarity of the R group will influence how different amino acids interact intramolecularly or intermolecularly with other molecules. On the other hand, lipids are made up of mainly hydrocarbons and are therefore insoluble in water. The saturation of different lipids vary, affecting the solidity of the lipid at room temperature. Fully saturated lipids have carbons saturated with hydrogens, while unsaturated lipids have double bonds between carbons, resulting in less surrounding hydrogens. Lastly, nucleic acids are composed of nucleotides that consist of a sugar ring, a phosphate group, and a nitrogenous base. The most recognized nucleic acid is DNA, and in DNA, nucleotide phosphate groups and sugars form phosphodiester bonds that make up the sugar-phosphate backbone. The nitrogenous bases form hydrogen bonds across the two strands of DNA to form the DNA ladder.