Download 7 - DNA.notebook

7 ­ DNA.notebook
March 14, 2014
DNA: Deoxyribonucleic Acid
A code in a cell's hereditary material; It
contains information for an organism‛s growth
and function.
• DNA is shaped like a spiral staircase called
a "double helix"
• Its shape is made up of the sides of the
ladder and the rungs (steps).
- Sides of the ladder = Deoxyribose and
Phosphates
- Rungs = Nitrogen Base Pairs
The nitrogen bases are:
Adenine
Thymine
These ALWAYS
pair together
Guanine
Cytosine
7 ­ DNA.notebook
March 14, 2014
7 ­ DNA.notebook
March 14, 2014
Chromosome: A structure formed of condensed (coiled
up) DNA.
*Humans have 23 chromosome pairs
(1 from Mom, 1 from Dad)
Karotype
Gene: A section of DNA on a chromosome that codes for
something.
-->Each chromosome has 100's of genes!
--> Some genes can be 1000's of nitrogen base
pairs long!
--> Each gene is located at a specific point along a
chromosome.
7 ­ DNA.notebook
March 14, 2014
SUPER SCIENTISTS!!!
Friedrich Miescher (1863) - The first
person to discover that "something" was
inside of the nucleus. He called this
discovery "Nuclein".
Rosalind Franklin (1950's) - Discovered the
helical structure of DNA has two strands when
she used an X-Ray method to look further into
the structure of DNA.
Watson and Crick (1953) - Used
Franklin's X-Ray information to piece
together their information on the four
nitrogen bases and sugar and phosphates.
With Franklin's discovery, Watson and
Crick solved the mystery of the structure
of DNA as what they called (and what we
still call) The Double Helix Molecule.
7 ­ DNA.notebook
March 14, 2014
DNA Replication
Replication - to make a copy of DNA
Enzyme -helps to regulate chemical cell
processes.
Attaches NB
Unzips NB
Step 1
DNA unzips with the help of
enzymes
Step 2
Enzymes attach new nitrogen bases
(that are floating in the nucleus) to
each of the unzipped strands.
Step 3
2 new sets of DNA are formed
Original Strand ...
ACGTAATCGT-
Unzips
...
2 New DNA
ACGTAATCGT-
ACGTAATCGTStrand 1
Strand 2
7 ­ DNA.notebook
March 14, 2014
Mutation: any change in the DNA sequence of a gene or
chromosome.
*Mutations occur when a segment of DNA is:
- deleted
- added
- substituted
ORIGINAL STRAND:
C C A A C C A A
G G T T G G T T
C C A A C A A
G G T T G T T
Base pair is deleted!
C C A A C C C A A
G G T T G G G T T
C C A A T C A A
G G T T A G T T
Base pair is added!
Base pair is substituted!
7 ­ DNA.notebook
March 14, 2014
7 ­ DNA.notebook
March 14, 2014
Notes
March 12, 2014
RNA (Ribonucleic Acid) -
Used to take DNA codes
and transfer them into proteins that the cell needs.
RNA vs. DNA
* RNA only has one strand
* DNA has two strands
* RNA does not have Thymine - The nitrogen base
Uracil replaces where Thymine should be in DNA
ACGTAATCGT-
1.
T
G
C
A
T
T
A
G
C
A
original DNA strand
2.
A
C
G
T
A
A
T
C
G
T
T
G
C
A
T
T
A
G
C
A
DNA strand separates when it needs to make a protein
(DNA is too big to fit out of the nucleus, so RNA needsto help out!)
3.
-U
-G
-C
-A
-U
-U
-A
-G
-C
-A
A
C
G
T
A
A
T
C
G
T
RNA makes a complimentarystrand that will "read" theDNA code.
4.
-U
-G
-C
-A
-U
-U
-A
-G
-C
-A
Amino Acids (molecules that makeproteins) attach to
the RNA andcreate what is needed