Section I Flashcards
What did Fred griffin experiment with
Pneumonia on mice
What was originally thought to carry genetic information
Proteins
What are single units, monomers
Nucleotides
What are the four nitrogen bases
Adenine
Thymine
Guanine
Cytosine
What year did Fred Griffith experiment
1928
What does the Griffith experiment prove
The genetic material is not protein
What are the three parts of a nucleotide
- five carbon sugar; deoxyribose
- phosphate group
- nitrogen base; one of four
What is protein denaturing
Breaking down of proteins in heat
In a nucleotide ___ and ___ stay the same but the ___ can change
Sugar and phosphate
Nitrogen bases
How do the nitrogen bases pair together
A-T, C-G
What 2 nitrogen bases are purines
Adenine and guanine
What 2 nitrogen bases are pyrimiones
Thymine and cytosine
What 2 nitrogen bases are double rings
Adenine and guanine
What 2 nitrogen bases are single ring
Thymine and cytosine
What are nitrogen bases combined by
A hydrogen bond
How was an image of DNA produced with Wilkins and Franklin
X-ray crystallography
What did Chargoff discover
That A=T and G=C
Who proposed the first model of DNA
Watson and Crick
When was the first DNA model proposed
1953
When did Watson and Crick earn their Nobel Prize and for what
1953 and physiology medicine
Who else was named to Watson and Crick’s Nobel Prize but could not be recognized because he died
Franklin
Where is DNA found in all cells
Nucleus
How is DNA found in resting cells
In strands known as chromatin
Before cell division, chromatin form ___
Chromosomes
What are genes
Short segments of DNA that contain specific information for traits
DNA polymerase only works in __–>__ direction
5’ and 3’
Fragments are added in segments of the ___ strand
Lagging
What are the two functions of DNA
- control of cells activities
- choose the type of proteins to be made
What do the “proof readers” consist of
20 or so amino acids
In the first step of DNA replication the DNA ___
Untwists
In the second step of DNA replication the ___ unzips the DNA at the nitrogen bases, breaking
DNA helicase
Breaking their hydrogen bonds
In the 3rd step of DNA replication free nitrogen bases from the nucleoplasm attach to the ___ by means of DNA polymerase
DNA
What is DNA glue
DNA ligase
What are the fragments in the lagging strand called
Okazaki fragments
The code for DNA replication would fill ___ text books
1,000
In step four of DNA replication the bases are reached and what is the result
Two DNA strands, one half being old DNA and the other half being new DNA
The correct process of DNA replication is called
Semi-conservative
On average how many errors are there per billion nucleotides
1
Replication occurs rapidly because
DNA is unzipped at a number of places at a time
How many chromosomes per cell
46
How many base pairs are there
3 billion
What do “proof readers” do
Check and correct mistakes in replication
What is the difference between virulent and non-virulent bacteria
Virulent - causes sickness
Non-virulent - doesn’t cause sickness
Polymerase moves along the ___ strand
Leading
How long does DNA replication take
A few hours
DNA has the ___ for traits
“Blueprints”
Because of the the size of the DNA m the DNA is
Too big to pass through the nuclear membrane
What does DNA stand for
Ribonucleic acid
Where in the cell are proteins made
Ribosomes, free floating, or attached to the ER
What are the parts of the DNA molecule
Sugar, ribose
Phosphate
Nitrogen bases
What are the four nitrogen bases in RNA
Adenine
Uracil
Cytosine
Guanine
What is the design of RNA
Single stranded
What are the three types of RNA
Messenger
Transfer
Ribosomal
What does the messenger RNA do
Carries code from DNA to the ribso r
What does the transfer RNA do
Single folded strand of RNA that carries the amino acids to ribosomes
What is the transfer RNA reused for
Picking up amino acids
What is ribosomal RNA made up of
Proteins
What is the major component of ribosomes
Ribosomal RNA
