2.3 Biological Chemistry Flashcards
Biological chemistry
Study of the chemical reactions and pathways of living cells and organisms
Combination of biological science and chemistry
Macromolecules
Extremely large molecules that can be composed of thousands of atoms
Building blocks for cells and carry out cellular functions
Types of macromolecules
Proteins
Carbohydrates
Lipids
Nucleic acids
Proteins
Polymers composed of alpha amino acids
Control the structure and function of cells
Several polypeptides folded together into a specific shape
Amino acid
Molecule with amine and carboxyl functional groups attached to an alpha carbon
Functional groups
Specific groupings of atoms within molecules that have their own characteristic properties regardless of other atoms present
Alpha carbon
Central to the molecule
In alpha amino acids the amine group, carboxyl group, and side chain are all attached to the alpha carbon
Side chain
Gives each of 20 amino acids its own properties
Essential amino acids
Amino acids that cannot be produced by the body
Peptides
Short chains of amino acids
Polypeptides
Chains of many amino acids connected by peptide bonds
Polymerization
Forming of peptides and proteins through peptide bonds
Peptide bonds
Formed via dehydration reaction
In organism, catalyzed enzyme called peptidyl transferase
Residue
An amino acid in a peptide or polypeptide
Mass of a polypeptide
Typically <5,000 g/mol
Mass of protein
5,000-40,000,000 g/mol
Primary structure
A protein’s amino acid sequence
Secondary structure
Largely driven by hydrogen bonding between the hydrogen on the nitrogen of one residue and the carbonyl carbon of another
Two main types are alpha-helices and beta-pleated sheets
Tertiary structure
Protein’s three dimensional shape, largely driven by hydrophobic areas of the protein that prefer to be buried in the interior of the structure.
Hydrophobic
Water-repelling
Quaternary structure
Arrangement of multiple polypeptide chains to form a larger protein
Alpha-helix
Peptide chain coils into a right-handed helix and hydrogen bonds form between coils
Beta-pleated sheets
Hydrogen bonds form from one strand to another. Side chains alternate between pointing to the inside or outside of the sheet and impacts the properties of the protein.
Pepsin
Protein that breaks down other proteins into smaller peptides and amino acids
Makes them easier to incorporate into the body for nutrition
Contains both alpha-helices and beta-pleated sheets
Denaturation
Process of a protein unfolding from its native structure
Can be due to changes in pH, temperature, and salt concentration
Denatured proteins generally aren’t active and typically irreversible
Enzymes
Class of proteins that catalyze reactions by acting upon a substrate
Catalyst
Speed up reaction by lowering activation energy
Lock-and-Key model
Substrate has to be specific shape and orientation to fit on the enzyme