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!

DNAWhich objects contain DNA?

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.

FilterEXTRACTION PROCEDURE ACTIVITY FUNCTIONFilter Separate the

components of the cell

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.

DNA Extraction Protocol Just follow these 3 easy steps:

Dissolve cell membranes Break down proteins Precipitate DNA

DNA

Detergent eNzymes(meat tenderizer

or salt)

Alcohol