Chapter 3 - Protein, Carbohydrates and Lipids Flashcards
Monomer
A molecule that can be covalently bonded to other identical molecules to form a polymer
Isomers
Molecules that have the same chemical formula, the same kinds and numbers of atoms, but with the atoms arranged differently
Structural Isomers
Isomers that differ in how their atoms are joined together
Cis-trans Isomers (geometric)
Same molecular formula but must contain a C=C (carbon carbon double bond)
Optical Isomers (stereoisomers or enantiomers)
Two 3D molecules that are mirror images of each other; not superimposable (placed on top of each other); one isomer typically is biologically active and the other isomer is inactive
Chiral Carbon
When a carbon atom has 4 different atoms or groups of atoms attached to it
Condensation (Dehydration) Reactions
Result in the formation of covalent bonds between the same type of monomers (ie. 2 amino acids, 2 nucleotides, etc); an H2O is removed
Hydrolysis
Result in the breakdown of polymers into their component monomers to release energy
Protein
Polymers made up of 20 amino acids in different proportions and sequences; most prevalent macromolecule
Zwitterion
A molecule or ion having separate positively and negatively charged groups
Amino Acids
Building blocks of protein; contains an amino group, a carboxyl group, a hydrogen and a R group (side chain) all attached to a carbon atom
Polypeptide chain
Single, unbranched chain of amino acids
Amino acids are in what 2 isomeric forms?
Amino acids are optical isomers with with a right side, D-amino acid, and a left side, L-amino acid; L-amino acids are found in organisms
Disulfide bridge
The terminal –SH group of cysteine can react with another cysteine side chain to form a disulfide bridge or disulfide bond (–S–S–); this creates protein folding in the tertiary structure
Primary structure of protein
Sequence of amino acids that determines the secondary and tertiary structure–how the protein is folded
Secondary structure of protein
Amino sequences creates two types of secondary structures: alpha helix and beta pleated sheet; these structures are due to the interactions of the backbone or polypeptide chain(s)
Alpha helix
Right handed coil (clockwise) resulting from hydrogen bonding between N–H groups on one amino acid and C=O groups on another
Beta pleated sheet
2 or more polypeptide chains that are aligned; hydrogen bonds form between the chains
Functional groups
Groups of atoms with specific chemical properties and consistent behavior; hydroxyl, aldehyde, keto, carboxyl, amino, phosphate, sulfhydryl functional groups