Chapter 5 Flashcards
Central Dogma
The fundamental concept in molecule biology that describe the flow of genetic information; DNA -> RNA -> Protein.
Genetic Material
The substance that carries heritable information from one generation to the next. In all known cellular life, this material is DNA
Heredity
The passing of physical or mental characteristics genetically from one generation to another
Transformation (in bacteria)
A process by which external DNA is taken up by a cell, resulting in a change in the cells genetic characteristics
Pathogenic
Capable of causing disease
Non-pathogenic
Not capable of causing disease
Transforming principle
The substance responsible for the heritable change of a cell. Identified as DNA by Avery, Macleod, McCarty
Bacteriophage
a virus that infects bacteria
Protein coat (capsid)
The outer protective layer of a virus, typically composed of protein
Radioactive isotope
An unstable form of an element that emits radiation as it decays to more stable form. Used as a label to track molecules in biological experiments
supernatant
a liquid that remains above the solid pellet after centrifugation
Pellet
The solid material that settles at the bottom of a tube after centrifugation. In the Hershey-chase experiment, this contained the bacterial cells
polymer
A large molecule composed of repeating subunits (monomers). DNA is a polymer of nucleotides
Nucleotides
The monomer unit of a nucleic acid, consisting of a five carbon sugar, a phosphate group, and a nitrogenous base
Phosphodiester bond
The covalent bond that links the nucleotides together in a DNA or RNA strand, connecting the sugar of one nucleotide to the phosphate of the next
Nitrogenous Base
A molecule containing nitrogen atoms and having chemical properties of a base. In DNA, the bases are adenine (A) guanine (G), cytosine (C), Thymine (T)
Purine
a double-ringer nitrogenous base (adenine and guanine)
Pyrimidine
A single-ringer nitrogenous base (cytosine and thymine)
Base composition
The relative amount of each of the four nitrogenous bases in a DNA molecule
Chargaff’s Rules
The observation that in DNA, the amount of adenine id equal to the amount of Thymine (A=T), and the amount of guanine is equal to the amount of cytosine (G-C)
X-ray Crystallography
technique used to determine the three-dimensional structure of molecules by analyzing the diffraction patter produced when X-rays pass through a crystallized sample
Double Helix
The twisted ladder shape of a DNA molecule, consisting of two antiparallel strands wound around each other
Antiparrallel
The orientation of the two strands of a DNA double Helix, which run in opposite directions (one strand runs 5’ to 3’, and the other 3’ to 5’)
Complementary base pairing
The specific hydrogen bond interactions between nitrogenous bases in DNA; Adenine (A) pairs with Thymine (T), and guanine (G) pairs with cytosine (C)