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Biomolecules: structure and functions Gaia Perone a.a. 2018-2019 1 Introduction. Biochemistry explains the chemical processes that happen within an organism in order to maintain the homeostasis. It studies the biomolecules, which are chemical structures characterized by a specific composition (C, H, O, N, P, Ca and S). Biomolecules can be divided in: ▪ Large macromolecules: proteins, carbohydrates, lipids and nucleic acids; ▪ Small molecules: metabolites, peptides. BIOMOLECULES. There are four families of biomolecules: 1. Carbohydrates; 2. Lipids; 3. Nucleic acids; 4. Proteins. 1. CARBOHYDRATES can be divided, depending on the molecular weight, in ▪ Simple: composed by a few molecules, for example: o Monosaccharide: glucose (6C+1O, exons); fructose (pentons); o Disaccharide: sucrose. ▪ Complex, Polysaccharide (glycogen). The functions of carbohydrates are: a. Storage energy (glycogen); b. Produce energy; c. Produce the structure of a cell. 2. LIPIDS (FAT) are composed by a long chain of carbon; they are non-polar and hydrophobic. For example triacylglycerol and phospholipid; this last one contain a phosphate which has a negative charge the increase the charge of a molecule. The functions of lipids are: a. Storage energy; b. Create a protection for the cell; c. Messenger molecule. 3. NUCLEIC ACIDS are the repletion of a specific unit, composed by a phosphate group, a sugar (ribose or 2-deoxyribos) and a nitrogenous base. There are two different type of nucleic acids (DNA and RNA) with different 3D structures. The functions of carbohydrates are: a. Hold genetic code; b. The synthesis of protein. 4. PROTEINS are complex structures composed by the repletion of specific units, called amino acid; the sequence of amino acids form the polypeptide chain, which is the first…