Ch 2 Nucleic Acids & 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.
tertiary structure
The functional 3D shape of 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.
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.
random coil
An irregular secondary structure of proteins that is neither an alpha helix nor a beta-pleated sheet.
disulphide bond
A strong covalent bond occurring between two sulphur atoms.
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,
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.
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.
nuclear DNA
DNA that is located in the nucleus of a cell.
messenger RNA (mRNA)
RNA molecules that are produced during transcription and carry genetic information from the nucleus to the ribosomes.