Amino Acids and Lipids Quiz

Amino Acids

• Organic compounds with an amino group and an acidic group on the same carbon (α-carbon), making them α-amino acids.
• Substituted methanes with four substituents: hydrogen, carboxyl group, amino group, and a variable R group.
• Many amino acids exist, but only twenty are found in proteins.
• The R group varies, determining the specific amino acid (e.g., glycine with hydrogen, alanine with methyl group).
• Chemical and physical properties largely depend on the amino, carboxyl, and R groups.
• Classified as acidic (e.g., glutamic acid), basic (lysine), or neutral (valine) based on the number of amino and carboxyl groups.
• Also categorized as aromatic amino acids (tyrosine, phenylalanine, tryptophan).
• Amino acids are ionizable, changing structure in different pH solutions.

Lipids

• Generally water-insoluble organic compounds.
• Simple lipids include fatty acids with a carboxyl group attached to an R group.
• R group can be methyl, ethyl, or longer hydrocarbon chains (1-19 carbons). Examples include palmitic acid (16 carbons) and arachidonic acid (20 carbons).
• Fatty acids can be saturated (no double bonds) or unsaturated (one or more double bonds).
• Another simple lipid is glycerol (trihydroxy propane).
• Many lipids combine glycerol and fatty acids, and the fatty acids are esterified to glycerol.
• These combinations are monoglycerides, diglycerides, and triglycerides ( fats and oils based on melting point).
• Oils have lower melting points (e.g., gingelly oil) and remain liquid in cooler temperatures.
• Phospholipids contain phosphorus and a phosphorylated organic compound, crucial for cell membranes (e.g., lecithin).
• Some lipids have complex structures, particularly in neural tissues.

Nucleic Acids

• Living organisms have carbon compounds with heterocyclic rings, including nitrogenous bases (adenine, guanine, cytosine, uracil, and thymine).
• When attached to a sugar, these nitrogenous bases are called nucleosides (e.g., adenosine, guanosine).
• Nucleotides are nucleosides with a phosphate group esterified to the sugar. (e.g., Adenylic acid, thymidylic acid).
• Nucleic acids (DNA and RNA) are polymers of nucleotides.
• DNA and RNA serve as genetic material.

Test your knowledge on amino acids and lipids, two essential classes of organic compounds. Learn about their structures, classifications, and properties. This quiz covers key concepts fundamental to biochemistry.