DNA CHAPTER 12

DO NOW: Write down in your notebook 5

things that you already know about DNA

DNA- DEOXYRIBONUCLEIC ACID 3 Main functions

___________ information ___________ information ___________ information

STORES INFORMATION Genes hold ___________ for cells They control the pattern of

______________

COPYING INFORMATION Cells must make a __________ ______ of every

single gene before the cell divides. The double-stranded DNA ___________ and the

2 strands serve as a template to make a ________________ strand.

End result is ____ identical ___________ of DNA.

TRANSMIT INFORMATION __________ are passed

down from parents to ____________

DNA is carefully ________ and ___________ along when a cell divides

COMPONENTS OF DNA

DNA is a ___________ _________ HINT!!! It is the NA in DNA

It is made up of ______________.

Nucleotides are joined into long strands by ____________ (sharing) bonds.

When DNA is formed there are _____ strands of _____________.

Each strand coils around the other forming the so called ____________.

SOLVING THE DNA STRUCTURE PUZZLE

________________ made an ______________ picture that showed DNA strands twisting around each other. _________

James _________ and Francis ___________ were attempting to build a DNA ________ but the pieces did not fit properly.

But once they saw __________ x-ray, they __________ the final piece of the puzzle.

NUCLEOTIDES Nucleotides are the ___________ blocks

of ___________ ___________. They have ________ parts:

a ________ (usually a 5 carbon sugar deoxyribose)

a ____________ group (P04) a __________ _______

NITROGENOUS BASES 4 types of nitrogenous bases

[A] ____________ [G] ____________ [C] ____________ [T] ____________

_____________ Rule

Adenine bonds with Thymine

_______ hydrogen bonds

Guanine bonds with Cytosine

_______ hydrogen bonds

DOUBLE HELIX MODEL DNA is a ___________ __________

structure A twisted ladder

The 2 strands are _______________ They run in ____________ directions Nitrogenous bases meet in the _________ of

both strands.

HYDROGEN BONDS ___________ bonds are between the nitrogenous

________ holding both __________ together.

Hydrogen bonds are _________ and pull ________ easily.

These types of bonds are beneficial for when replication takes place

Sugardeoxyribose

Phosphate group

EXAMPLE QUESTION 5’ AGAATCGCATTC 3’

5’ GCTCAACTTG 3’

5’ TACAGGCAT 3’

A T C GHuman #1 20 30Human #2 24.5Human #3 17

DO NOW QUESTIONS What are the 3 main functions of DNA?

What is the function of genes?

What is a nucleic acid and what is it composed of?

DNA REPLICATION ___________- is to make a ________ of

DNA1) DNA molecule will ________ the _________ bonds and

___________ into _________ strands.a) just like a zipper would undo

2) Each strand of the double helix acts as a ___________ for making the ________ strand.

3) As each new strand forms, _____ _________ are added following the rules of base pairing.

__________ ___________4) End result is _____ ______________ DNA molecules.

TELOMERES

_______________ are the tips of chromosomes that are _________ to ____________.

Cells use an enzyme called ____________ to insure that genes will not be damaged or lost during replication.

Telomerase is usually ________ _____ in adults.

Many scientist believe that in __________ ______, telomerase is turned ______ and that may be why cancer cells ________ and divide so __________.

DNA REPLICATION ERRORS Proteins ___________ the copies to make

sure they are accurate.

Unfortunately, some errors are ____ _________ and that may cause a ________ in base order, resulting in a ____________.

Some mutations have ________ consequences.