DNA Unit Exam Bio 30

DNA

Stores genetic info, provides instructions for making proteins

Gene

Specific section of DNA, codes for a particular protein or trait

Chromosome

Tightly coiled structure of DNA and proteins found in the nucleus that contains many genes

Nucleotide

Part of DNA, made of a sugar, base , and phosphate group, helps build new strand

Nitrogen Base

Adennine, Thymine, Cytosine, Guanine

Base Pairing

Nitrogen base matching, A-T, C-G

Sugar-Posphate Backbone

Sides of the DNA ladder made of alternating sugar and phosphate molecules

Complementary Strand

New DNA strand formed by matching bases to an exsisting strand

Mutation

Change of DNA

RNA

aids in protein creation

DNA replication emzymes

Helicase, Primase, DNA polymerase, DNA ligase, Topoisomerase (work together to copy DNA)

Helicase

Unzips DNA double helix by breaking H bonds, works before polymerase can add new nucleotides

Ligase

Joins DNA fragments together (lagging strand especially)

Primase

puts down RNA primers to begin replication

Polymerase

Builds new strand by adding nucleotides

m-RNA

carries instructions from DNA to build protein

t-RNA

brings amino-acids to build protein

r-RNA

makes up ribosomes

Transcription

m-RNA - DNA

Translation

m-RNA - protein

number of m-RNA codons

61 for acids, 3 for stop codons(stop protein synthesis)

t-RNA Anticodons match…

mRNA codons to build the correct protein using amino acids (au)(cg)

Fred Miescher

DNA discovery, 1869

Phoebus Levene

• 2 Nucleotides discovery (purines and pyrimidines), 1909-1929

• Discovered that cells contain DNA and RNA

Purines are…

Double ringed structure, A - G

Pyrimidines

Single ringed structure, T - C

Thomas Morgan

Linked chromosomes and hereditary, and different in autosomal chromosomes and sex chromosomes

Avery-McCarty-Mcleod

1944 discovery that DNA transmitted info/genetic material

Erwin Chargaff

• 1950

• 4 rules

• # of A’s = #’s of C’s (same for T and G)

• # of (A + C) doesn’t equal # of (T + G)

• Ratio is the same in all cells in an organism

• # of purines doesn’t equal the # of pyrimidines

Rosalind Franklin

1951-1953, 1st xray of DNA led to discovery of double helix, photo 51