Post on 02-Jan-2016
Bellringer Wed, 01/07Replicate the following DNA strand
(hint: find the complementary nucleotides and remember your base pairings)ATGGCTAGCCTTTTAACGC
What is RNA? Look it up!
Reminders: HW #17 due Fri, LAB FEE anytime,
5 days to FINAL EXAMS!
Prior KnowledgeDNA is found in the cell of every living thing.Proteins that help DNA maintain its form may
obscure our ability to see the DNA so they must be removed.
Among eukaryotes, DNA is contained in themembrane wrapped nucleus.
The cell membrane is made of lipids withembedded proteins.
DNA FactsDNA FactsEach cell contains 9 feet of DNAIn an average meal, you EAT approximately
55,000,000 cellsThis is equal to approximately 93,205 miles
of DNAIf the total DNA in one person were laid
in a straight line, it would stretch to the sun and back over 30 times (it’s 93 million miles from here to the sun)
Problem The Biotech Foods Company is developing an
improved strain of bananas through genetic engineering. In order to obtain DNA that they can examine and use, scientists working for the company must extract the DNA from banana cells in a way that does not destroy the DNA molecules. Conditions that can damage or destroy DNA molecules include exposure to heat, acids, and ultraviolet radiation. In this lab you will follow a simple procedure for extracting DNA.
To extract the DNA ….. Which parts of the cell do you have to go through to remove the DNA?
BARRIERS TO OVERCOME
BARRIER 1: Cell Wall (only in plant)
BARRIER 2: Cell membrane
BARRIER 3: Nuclear membrane
BARRIER 1 - Cell WallEXTRACTION PROCEDURE ACTIVITY FUNCTION
Mashing/Crushing This breaks open the cell (LYSE) wall, cell membrane, and the nuclear envelope to allow the DNA to be released.
BARRIER 2 – Cell Membrane &BARRIER 3- Nuclear Membrane
EXTRACTION PROCEDUREACTIVITY FUNCTION
Detergent (buffer) Breakdown the fat and proteins that make up the cell and nuclear membrane. (Just like the detergent dissolves grease on your dishes).
Cell MembraneWhat components make up the membrane that surrounds the cell?
REMEMBERCell membranes are made of phospholipids
Cell MembraneCell MembranePhospholipids are bi-layer,
with a head and a tail.
the head –LOVES WATER
the tail – HATES WATER
Phospholipids won’t dissolve in water
HATES Water
LOVES Water
Protein wrapped around DNAEXTRACTION PROCEDURE
ACTIVITY FUNCTIONMeat tenderizer
(Enzyme)Adding an enzyme, such
as meat tenderizer will break down proteins such as nucleases and histones that are wound around the DNA.
Last Step!EXTRACTION PROCEDURE ACTIVITY FUNCTION
Alcohol
DNA does not dissolve in alcohol. (It is soluable in water).
The addition of alcohol causes the DNA to precipitate.