Chapter 2 - Nucleic Acids and Proteins 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 catalyses (speeds up) specific reactions
peptide hormone
a protein signalling molecule that regulates
physiology or behaviour
antibody
a protein produced by
plasma cells during the adaptive immune response that is specific to an antigen and combats pathogens in a variety of ways. Also known as immunoglobulin
carboxyl group
the functional group on amino acid molecules that contains a hydroxyl group
(OH) and an oxygen
double-bonded to a carbon atom
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
hydrophobic
having a tendency to repel and be insoluble in water
hydrophilic
having a tendency to be attracted to and dissolve in water
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
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
alpha helix
an organised coiled secondary structure of proteins
beta-pleated sheet
an organised folded secondary structure of proteins
disulphide bond
a strong covalent bond occurring between two sulphur atoms
random coil
an irregular secondary structure of proteins that is neither an alpha helix nor a beta-pleated sheet
prosthetic group
a non-protein group bound to a protein. For example, a vitamin or ion
nucleic acid
the class of macromolecule that includes DNA and RNA. All nucleic acids are polymers made out of nucleotide monomers
polymer
a large molecule that is made up of small, repeated monomer subunits
nucleotide
the monomer subunit of nucleic acids. Made up of a nitrogen-containing base, a five-carbon sugar molecule (ribose in RNA and deoxyribose in DNA), and a phosphate group
monomer
a molecule that is the smallest building block of a polymer
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 singlestranded 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
condensation reaction
a reaction where two monomers join to form a larger molecule, producing water as a by-product
sugar-phosphate backbone
a strong covalently linked chain of five-carbon sugar molecules and phosphate groups in a nucleic acid chain
chromosome
a structure made of protein and nucleic acids that carries genetic information
gene
a section of DNA that carries the code to make a protein
genome
the complete set of DNA housed within an organism
antiparallel
a characteristic of DNA strands describing how each strand runs in an opposite direction to the other. One strand runs in a 3’ 5’ direction and the other runs in a 5’ 3’ direction
complementary base pairing
describes which nucleotides can form hydrogen bonds with each other. C pairs with G, A pairs with T (or U in RNA)
double helix
the structure of double-stranded DNA in the nucleus of eukaryotic cells, where each DNA strand wraps around a central axis