DNA- chapter 12- part 2

Fredrick Griffith

Discovered transforming principal with two strains of pneumonia bacteria and mice.

Avery/McCloud

Discovered DNA was transforming factor by process of elimination

Hershey/Chase

bacterial viruses- called phages- were used to definitively prove that DNA is the genetic material

Chargaff

Showed that in DNA the amount of A is equal to the amount of T and the amount of C is equal to the amount of G

Watson and Crick

Discovered/Proved that DNA took the shape of a double helix

Rosalind Franklin

Took x-rays of DNA to reveal that it was helical in structure with even spacing within the molecule

What is the difference between a nucleotide and a nitrogenous base?

A nucleotide is made up of three parts; a sugar, a phosphate and a nitrogenous base. So the nitrogenous base is a part of the nucleotide.

What is the purpose of DNA?

It is the genetic material responsible for carrying out all of the functions in the body- the blueprints for life

What does DNA stand for?

Deoxyribonucleic Acid

What does RNA stand for?

Ribonucleic Acid

What makes DNA different than RNA?

The sugar, its the location it functions, T vs U, and the number of strands that make it up.

purines

Adenine and Guanine- double ring structure

pyrimidines

Thymine, Cytosine and Uracil - Single ring structure

In RNA what nitrogenous base pairs with Adenine?

Uracil.

Nucleotide

A Monomer of DNA

In what direction MUST DNA be assembled?

5' to 3'

Where is DNA found?

The nucleus.

What enzyme is responsible for unwinding the DNA?

DNA helicase

What enzyme is responsible for adding nitrogenous bases to the newly synthesized DNA strand?

DNA Polymerase

How many molecules of DNA are present in one double strand?

Two.

What are the three parts to a nucleotide?

Sugar, Phosphate and a Nitrogenous Base

What does tRNA stand for?

transfer RNA

What does rRNA stand for?

ribosomal RNA

What does rRNA do?

Forms ribosomes

What occours in transcription?

a mRNA strand is formed from the DNA strand in the nucleus

Codon

a nucleotide triplet in mRNA that codes for a specific amino acid

tRNA

uses the anti-codon to bring an amino acid to its codon in translation

translation

the mRNA code is made into protein with the help of the anticodon and tRNA

hydrogen bonds

holds the two strands of the double helix together by bonding between the complementary nitrogenous bases

covalent bonds

holds the sugar-phosphate backbone together in DNA

gene

section of DNA that has the information coded for one particular protein

anticodon

only found in tRNA- used to bring amino acid to ribosome for protein synthesis

RNA Polymerase

enzyme responsible for adding nucleotides during transcription

Okazaki Fragments

short, newly synthesized DNA fragments that are formed on the lagging template strand during DNA replication.

Leading Strand

strand in DNA replication where nucelotides are added continuously in the 5' to 3' direction

Lagging Strand

strand in DNA replication where nucleotides are added in small fragments that are later connected together

5' to 3'

The direction DNA is synthesized

Transcription

Using the DNA template a complimentary mRNA strand is synthesized

What are the three parts to a DNA nucleotide?

Deoxyribose, A Phosphate and a nitrogen base (A, T, C or G)

What are the three parts to an RNA nucleotide?

Ribose, a phosphate, and a nitrogen base (A, U, C or G)

mRNA

Messenger RNA

Nobel Prize Winners for discovering DNA

Watson, Crick, Wilkens

DNA Backbone

the sides of the ladder- comprised of alternating Deoxyribose sugars and phosphates held together by covalent bonds

Number of codons used in protien synthesis

64

Number of amino acids availible

20

How many amino acids does each codon code for?

One (Ex. AUG only codes for Methionine!)

Ribosome

Place in cytoplasm where protein synthesis takes place, made up of rRNA

Base Pairs in DNA

A-T and C-G

Base Pairs in RNA

A-U and C-G

Start Codon

AUG- Methionine- signals the start of protein synthesis

Stop Codon

Signals the end of protein synthesis, allows polypeptide to be released from the ribosome

Gyrase

Nicks open DNA

Single Stranded Binding Proteins

hold separated DNA strands apart

How many parts does a nucleotide have?

THREE- Sugar, Phosphate, Base