nucleotide

Building block of a nucleic acid, consisting of a phosphate group, a nitrogenous base, and a five-carbon sugar.

Biochemist who showed that DNA contains equal amounts of adenine (A) & thymine (T), and equal amounts of guanine (G) and cytosine (C).

Maurice Wilkins & Rosalind Franklin

Discovered DNA's three-dimensional shape using x-rays (x-ray diffraction).

James Watson & Francis Crick

Combined the previous discoveries to make the 3-D ball and stick model of DNA that we know of today. DNA is a double helix.

Twin rails of the DNA ladder are also called...

Sugar-phosphate "backbones," which are alternating units of deoxyribose and phosphate joined with covalent bonds  

The ladder's rungs are...

A-T and G-C base pairs joined by hydrogen bonds

complementary

in DNA and RNA, the precise pairing of purines (A and ) to pyrimidines (C, T, and U) such that each strand defines the sequence of the other

genome

all the genetic material in an organism

chromosomes

a continuous molecule of DNA wrapped around protein in the nucleus of a eukaryotic cell; also, the genetic material of a prokaryotic cell

gene

sequence of DNA that codes for a specific protein or RNA molecule

Genetic "Recipe"

1. Inside the nucleus, an enzyme copies the gene's DNA sequence to a complementary RNA sequence.
2. After modification, RNA emerges from nucleus and binds with a ribosome in the cytoplasm.
3. At the ribosome, amino acids assemble in a specific order to make a protein based on the RNA's prescribed sequence of nucleotides

Before a cell divides, its DNA must replicate.. why?

So that each daughter cell receives the same set of genetic instructions.

Semiconservative

each DNA double helix conserves half of the original molecule and combines with a newly constructed molecule

DNA polymerase

enzyme that adds new DNA nucleotides and corrects mismatched base pairs in DNA replication

Helicase

an enzyme that unwinds the double helix

Primase

adds short RNA primer to template strand

Ligase

an enzyme that catalyzes formation of covalent bonds in the DNA sugar-phosphate backbone; repairs the Okazaki fragments

Okazaki fragments

a relatively short fragment of DNA created on the lagging strand during DNA replication -- lagging occurs because the DNA polymerse only moves in a 5'-3' direction.

alleles

an alternative form of a gene; variants of genes

mutation

a change in a DNA sequence

polymerase chain reaction (PCR)

biotechnology tool that rapidly produces millions of copies of a DNA sequence of interest

PCR rapidly replicates a selected sequence of DNA in a test tube. The requirements include:

• a target DNA sequence to replicate
• Taq polymerase
• Two types of short, lab-made primers that are complementary to opposite ends of the target sequence
• a supply of the four types of DNA nucleotides

Taq Polymerase

a heat tolerant DNA polymerase 

DNA Microarray

collection of short DNA fragments of known sequence placed in defined spots on a small square of glass

DNA profiling

Fredrick Grifith

Avery, Macleod, & McCarty

showed that genetic info is DNA; discovered that by using a DNA destroying enzyme (DNase) the infection wasn't spread to the mouse

Hershey & Chase

confirmed the genetic role of DNA by examining/experimenting with bacteria. That DNA was the genetic material that could allow the virus to replicate.