BIO 190 Lab #7- DNA and Blast

DNA is composed of a double chain of 4 alternating ________

nucleotides

each nucleotide contains a ..

sugar, phosphate group, nitrogenous base

what are the 4 nitrogenous bases for DNA

Adenine, Thymine, Guanine, Cytosine

describe Watson and cricks work (know the year)

in 1953 they compiled all info known about DNA and published their proposed structure: a double helix with an outer sugar phosphate backbone and paired bases facing inwards

what did Rosalind Franklin do (year)

in 1953 she determined the spacial relationships of the backbone, that A form is antiparallel using X-rays to show structure of DNA

What did Alfred Hershey and Martha Chase do? (year)

1952, they used bacteriophages grown in radioactive medium to show that DNA enters the cells as transforming agents

what did Erwin Chargoff do (year)

(1949) found that the amount of adenine = thymine and guanine= cytosine

3 things that differentiate RNA from DNA

sugar, single strand, uracil

What did Frederick Griffith discover? (year)

1928, discovers that heat killed bacteria can transform a non virulent strain. genetic material is a heat stable chemical

what did Oswald Avery, McAllen McCarty and Collin McLeod identify (year)

1944 they identified griffths transforming agent as DNA

only DNA is capable of transforming the non virulent strain of bacteria

what did thomas hunt morgan do (year)

1915 used fruit flys to provide direct evidence is chromosome theory of inheritance

DNA replication

The process in which DNA makes a duplicate copy of itself.

where does DNA replication take place

in the nucleus during the S phase

what triggers DNA replication

enzymes

overview of the steps of DNA replication

1. replication begins when DNA is unwound and the two strands separate from each other along the hydrogen bonding pairs

2. each old strand is a template for the new bases and base pair rules are followed

3. 2 new strands are formed using information from the original parent strands. each molecule has an old parent strand and a new daughter strand = semiconservative

what is semiconservative replication

Each new helix contains a strand from the parent DNA molecule and a newly synthesized strand.

DNA holds the codes for the ___________ that builds a ____________

amino acids; protein

where does protein synthesis occur

the cytoplasm

the code from DNA is copied through the process of ___________ and the copy goes to the cytoplasm to be used to create proteins through ______________

transcription; translation

when the code on a strand of DNA is transcribed a strand of _______ is produced

mRNA

after transcription the mRNA moved out of the nucleus and into the _______

cytoplasm to the site of protein synthesis which are ribosomes

What is ribosomal RNA (rRNA)?

RNA that becomes part of ribosomes (the main component of ribosomes) and catalyzes the bonding of amino acids

what does tRNA do

picks up amino acids

each tRNA picks up a certain amino acid and moves it to the ribosome

a strand of mRNA is sub divied into____

codons

what did the lysis buffer do in the DNA lab

broke open the cells in our solution

what did protease do in the DNA lab?

digests other proteins in the cell

what did we need to place our test tube in the 50 celcius water bath for 10 minutes after adding protease

because protease is active at high temperatures

mutation

DNA code that has an error in it

sickle cell anemia

a genetic disorder that causes sickle shape in blood cells which can not pass along narrow capillaries. this causes poor circulation

(look for flat cells)

normal blood cells

normal size and color

How does transcription start

when transcription factors bind to enhancer elements which allow RNA polymerase to bind to the promotor

what is the G cap

- added to the 5' end of mature mRNA

- made of a modified guanine nucelotide with three phospates

- protects the mature mRNA from degradation in the cytoplasm

what is the poly A tail

-string of adenine nucleotides at the 3' end of mature mRNAs.

-aids in the export of mRNAs from the nucleus and causes the mRNA to be more stable and exist for longer

-has opposite effect in bacteria, causing the mRNA to degrade

introns vs exons

Exons contain the actual genetic information coding for protein.

Introns are intervening noncoding segments of DNA. ("IN trons stay IN the nucleus, whereas EX ons EX it and are EX pressed")

what does BLAST stand for

Basic Local Alignment Search Tool

what does BLAST do

finds regions of local similarity between sequences

how many nitrogenous bases are there

four

why are they called nitrogenous bases

because they contain nitrogen atoms, and "bases" due to their ability to act as proton acceptors, similar to the chemical behavior of a base

which 2 nucleotides are purines

Adenine and Guanine

which 2 nucleotides are pyrimidines

thymine and cytosine

purine vs pyrimidines

purine: A, G, two rings

pyrimidines: C, T, U, 1 ring

how many hydrogen bonds bind A-T together

2

steps of DNA replication, transcription, and translation

1. Initiation

2. Elongation

3. Termination

what triggers DNA replication

helicase unwinding

semiconservative replication

each new DNA molecule consists of one new strand and one old strand

describe translation

Process where the information carried by mRNA is used to produce proteins.

where does translation occur

cytoplasm / ribosome

are amino acids monomers or polymers

monomers

how are amino acids bound together to form proteins

peptide bonds

what is hemoglobin

A protein in red blood cells that carries oxygen.

what type of mutation was sickle cell anemia

point mutation in the beta-globin gene (HBB) on chromosome 11

what type of bond is between nitrogenous bases

hydrogen bonds

what type of bond is between nucleotides

phosphodiester bond

(the strong stable bond for structure around the backbone)