Key Knowledge 1 Flashcards
protein
a biomacromolecule made of amino acid chains folded into a 3D shape
polypeptide
a long chain of amino acids. Proteins can be made of one or many polypeptides
proteome
all the proteins that are expressed by a cell or organism at a given time
enzyme
an organic molecule, typically a protein, that speeds up specific reactions
carboxyl group
the functional group on amino acid molecules that contains a hydroxyl group (OH) and an oxygen doublebonded to a carbon atom
what does an amino acid consist of
a central carbon atom that is bonded to a hydrogen atom, a carboxyl group (COOH), an amino group (NH2), and an R-group
amino group
the functional group on amino acid molecules that is made up of one nitrogen and two hydrogens (NH2)
R-group
the variable portion of an amino acid molecule. It can be one of twenty variations and determines the identity of the amino acid
R-groups chemical properties and example
can affect how different amino acids within a protein interact with each other.
For example, an amino acid with a hydrophobic R-group is more likely to form bonds with other hydrophobic R-group amino acids than it would with an amino acid containing a hydrophilic R-group.
monomer
a molecule that is the smallest building block of a polymer
polymer
a large molecule that is made up of small, repeated monomer subunits
condensation reaction
a reaction where two monomers join to form a larger molecule, producing water as a by-product
peptide bond
the chemical bond linking two amino acids
where does the joining of amino acids together occur?
cell’s ribosomes via condensation reaction
primary structure
the first level of protein structure, which refers to the sequence of amino acids in a polypeptide chain
secondary structure
the level of protein structure where the amino acid chain forms either alpha-helices, beta-pleated sheets, or random coils
tertiary structure
the functional 3D shape of a polypeptide chain
quaternary structure
the level of protein structure where multiple polypeptide chains bond together, or other non-protein groups are added to form a fully functional protein
nucleic acid
the class of macromolecule that includes DNA and RNA. All nucleic acids are polymers made out of nucleotide monomers
Every nucleotide includes
• a phosphate group
• a five-carbon (pentose) sugar
• a nitrogen-containing base.
5 carbons
first carbon being labeled 1’ (one prime) and the last carbon being labeled 5’ (five prime). The three carbons of particular interest include:
• 1’ which attaches to the nitrogenous base
• 3’ which attaches to the phosphate of the following nucleotide
• 5’ which attaches the five-carbon sugar to the phosphate group of the nucleotide.
DNA (deoxyribonucleic acid)
a double-stranded nucleic acid chain made up of nucleotides. DNA carries the instructions for proteins which are required for cell and organism survival
RNA (ribonucleic acid)
a single stranded nucleic acid chain made up of nucleotides. Includes mRNA, rRNA, and tRNA
phosphodiester bond
a strong covalent bond linking a five-carbon sugar to a phosphate group
sugar-phosphate backbone
a strong covalently linked chain of five-carbon sugar molecules and phosphate groups in a nucleic acid chain