Genetics Ch 9

avery lundell

Miccher

discovered nuclein- nucleic acid (nitrogen and phosphorus)

Garrod

connected metabolic diseases with missing enzymes

Griffith

discovered bacteria tranformation

Avery, MacLeod, McCarthy

showed DNA is the transforming principle

Hershey, Chase

shows that the virus tranfers DNA, not protein, into the cell

Levene

discovered 3 parts of a nucleotide (sugar, phosphate, base) and the distinction between DNA and RNA

Chargaff

discovered DNA basic relationships ( A+G=T+C; A=T C=G; A+G are purines; T+C are pyrimidines)

Franklin, Gosling, Wilkins

DNA structure (2 strands, double helix, sides are sugar + phosphate, middle = nitrogenous pair)

Watson, Crick

did no experimenting, used a combination of other people’s work to build a cardboard model to solve the structure of DNA

gene

sections of DNA molecule (that contains info used to determine the amino acid sequence of a particular protein)

nucleotide

single building block

DNA

deoxyribose sugar, phosphate group, nitrogenous base (A T C or G)

sugar phosphate backbone

nucleotides joined to chains to form

double helix

two aligned polynucleotides joined to chains to form

DNA is…

directional 5’ to 3’ then 3’ to 5’

complementary base pairing

A + G and T + C (hydrogen bonds)

histones

protein that DNA wraps around

chromatin

DNA and associated protein that make up DNA material

chromatid

one of the two identical copies of a replicated chromosome

nucleosome

DNA is wrapped around histone proteins

DNA looping

forms a loop when chromatin is loose

DNA replication

process of making identical copies of DNA; semiconservative- each new DNA molecule contains one original strand and one new strand

replication fork

site where DNA is opened

helicase

unwinds double helix

binding proteins

stabilize separate strands

primase

adds a short primer to the template strand

DNA polymerase

binds nucleotides to form new strands

ligase

joins okazaki fragments and seals other nicks in sugar phosphate backbone

replication bubbles

DNA rep begins at multiple location, they look like bubbles, eventually expand and join together as more rep happens

PCR (polymerase chain reaction)

technique used to make copies of a specific DNA (1. denaturation 2. annealing 3. extension)

denaturation

high temp, hydrogen bonds break

annealing

lowered temp, primers bind to target

extension

adds new nucleotides to each primer

DNA sequence

determining the order of nucleotide bases in DNA

DNA sequence - sanger

used to sequence individual genes, ddntps stop sequence

automated - DNA sequence

uses fluorescently labeled ddntps, the computer analyzes these, uploads these DNA sequences displayed on a graph

DNA sequence - new generation

sequences many DNA fragments at the same time, makes DNA sequencing much faster, a human genome can be sequenced in hours