Amino Acids and Proteins in Biochemistry, Study notes of Biochemistry

Download Amino Acids and Proteins in Biochemistry and more Study notes Biochemistry in PDF only on Docsity! BIOCHEMISTRY PRELIMINARY SY. 2023-2024 Lecture/First Semester/Week 3 AMINO ACIDS AND PROTEINS Proteins - are complex macromolecules that are polymers of many subunits called amino acids - roles in living things - catalysts-enzymes - hormones - transport molecules - key part of structures - muscle action - immune response - visual process - operation of the nervous system - Proteins come in all shapes and sizes Amino Acids - these are small molecules with a simple basic structure, a carbon atom to which three groups are added - amino group (-NH2) - carboxyl group (-COOH) - Functional group gives amino acids their chemical identity - Basic Structure of an Amino Acid - Things to remember about amino acids: - only 20 L-amino acids are used to make proteins; AA are joined by peptide bonds - side chains or side groups are what distinguish amino acids from each other - amino acids can exist as zwitterions (a molecule or ion having separate positively and negatively charged groups) - Writing AA starts from N-terminus to C-terminus - Classification of Amino Acids: I. Polarity - polar - acidic - basic - neutral - nonpolar II. R group - acidic - basic - neutral III. Nutrition - essential - non-essential 1 BIOCHEMISTRY TRANSES Lecture/First Semester/Week 3 Proteins - the covalent bond linking two amino acids together is called a peptide bond - the assembled polymer is called polypeptide Polypeptide - Count the amino acid residue - To find the peptide bond locate the carbonyl Proteins structure - protein structure is complex - the order of the amino acids that form the polypeptide affects how the protein folds together - the way that a polypeptide folds to form the protein determines the protein's function - some proteins are comprised of more than one polypeptide - Primary Protein Structure - Sequence of a chain of amino acids - Secondary Protein Structure - Local folding of the polypeptide chain into helices or sheets - Tertiary Protein Structure - Three-dimensional folding pattern of a protein due to side chain interactions 2