Download DNA is - Ms. Dooley`s Science Class

Bell Work
• Quick Write (3 lines): How do codes work?
• Rules for Quick Write:
1. I write all my ideas and questions.
2. All my answers are okay
3. I write the minimum number of lines.
4. I skip lines
5. This is my best effort
http://faculty.uca.edu/~johnc/mbi1440.htm
DNA
http://www.wappingersschools.org/RCK/staff/teacherhp/johnson/visualvocab/mRNA.gif
DNA is a DOUBLE HELIX
http://www.time.com/time/time100/scientist/profile/watsoncrick.html
http://en.wikipedia.org/wiki/Rosalind_Franklin
X-ray experiments by Rosalind Franklin
led James Watson and Francis Crick to the
discovery of the structure of DNA in 1953
Figure 12–7 Structure of DNA
Section 12-1
Nucleotide
Hydrogen
bonds
Sugar-phosphate
backbone
Key
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
NUCLEIC ACIDS are built from
subunits called
____________________
NUCLEOTIDES
Image by: Riedell
SUGAR in DNA is
deoxyribose
________________
NITROGEN BASES in DNA
_____________=
ADENINE A
_____________
GUANINE = G
_____________
CYTOSINE = C
______________
THYMINE = T
No URACIL
DEOXYRIBONUCLEIC ACID
DOUBLE
______________
STRANDED
Image from: http://www.tokyo-med.ac.jp/genet/picts/dna.jpg
Backbone
(sides of ladder)
made of
PHOSPHATES
_____________
and
sugars
_____________
Nitrogen bases =“Steps of ladder”
A
Phosphate
group
G
Deoxyribose
sugar
C
T
Purines
(2 rings)
Pyrimidines
(1 ring)
© Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved
CHARGAFF’S RULES
A = T
G = C
_________
_________
At time no one knew why…
now we know its because
Adenine always bonds
THYMINE
across with____________
Guanine always bonds
CYTOSINE
across with ____________
Image from: http://evolution.berkeley.edu/evosite/evo101/images/dna_bases.gif
DOUBLE HELIX
Hydrogen
_____________ bonds
between nitrogen bases
hold the two strands
together.
Image from: http://evolution.berkeley.edu/evosite/evo101/images/dna_bases.gif
Bell Work
• What is Chargaff’s rule?
– Number of Adenine (A) = Thymine (T)
– Number of Cytosine ( C) = Guanine (G)
• Label the following:
Nitrogen Base
Sugar & Phosphate
Backbone
Hydrogen Bonds
Bell Work
• What are purines? What are the two DNA
bases of purines?
– Purines have 2 rings
– Adenine (A) & Guanine (G) are purines
• What are pyrimidines? What are the two DNA
bases that are pyrimidines?
– Pyrimidines have 1 ring
– Thymine (T) & Cytosine (C) are pyrimidines
Bell Work
• Explain the structure of DNA using the following
words:
• Adenine, Thymine, Cytosine, Guanine, Hydrogen
bonds, double helix, phosphate groups, 5 carbon
sugar, base pairing
•
1.
2.
3.
4.
5.
REMEMBER: Rules for Quick Write:
I write all my ideas and questions.
All my answers are okay
I write the minimum number of lines.
I skip lines
This is my best effort
CHROMOSOMES &
DNA REPLICATION
Chromosome Structure of Eukaryotes
© Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved
Chromosome
Nucleosome
DNA
double
helix
Coils
Supercoils
DNA is:
multiple
______________
in chromosome bundles
______________
Found in __________
nucleus
Histones
© Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved
Chromosome Structure of Eukaryotes
Nucleosome
Chromosome
DNA
double
helix
Coils
Supercoils
Histones
Nucleosomes pack together to form thick
coiled fibers. When cell is NOT dividing,
these fibers are spread out in nucleus as
CHROMATIN (Allows reading of code)
___________.
Chromosome Structure of Eukaryotes
© Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved
Chromosome
Nucleosome
DNA
double
helix
Coils
Supercoils
When cell gets ready to divide, the
fibers pack even more tightly to form
chromosomes
___________.(Makes
it easier to move
DNA during mitosis)
Histones
Image from: http://evolution.berkeley.edu/evosite/evo101/images/dna_bases.gif
HOW IS DNA COPIED?
Each strand has all the info
needed to construct
matching
the __________other
half.
If strands are separated,
base-pairing
_____________
rules allow
you to fill in the
complementary bases.
Each strand acts as a
template for the other.
Figure 12–11 DNA Replication
DNA is copied using a process called:
REPLICATION
Section 12-2
New strand
Original
strand
DNA
polymerase
Growth
DNA
polymerase
Growth
Replication
fork
Replication
fork
New strand
Original
strand
Nitrogenous
bases
Sites where strand separation and
replication forks
replication occur are called _____________
Bell Work
A T
C G
T A
C G
G C
A T
G C
FILL IN THE
MATCHING/MISSING
DNA BASE PAIRS
Bell Work
• What does DNA stand for?
– DeoxyriboNucleic Acid!
• How many nitrogenous bases are there in
DNA?
–4
• What are the 4 nitrogenous bases in DNA?
– Adenine = Thymine
– Guanine = Cytosine
Bell Work
• What does it mean to transcribe something?
– To write a copy of it
• In transcription, DNA is transcribed to produce a
molecule of RNA.
• What does it mean to translate something?
– To express something in another language
• Message encoded by RNA is translated into a protein
during the process of translation.
RNA and PROTEIN SYNTHESIS
© Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved
DNA MASTER PLAN
*stay safe in nucleus for Replication (DNADNA)
TRANSCRIPTION (DNA→ RNA)
*takes place in nucleus
TRANSLATION (RNA→ proteins)
*takes place on ribosomes in cytoplasm
3 KINDS OF RNA HELP WITH INFO
TRANSFER FOR PROTEIN SYNTHESIS
MESSENGER RNA (mRNA)
_________________
carries code from DNA to ribosomes
RIBOSOMAL RNA (rRNA)
_________________
Combines with proteins to form ribosomes
TRANSFER
_________________RNA
(tRNA)
Matches m-RNA codon to add correct
amino acids during protein synthesis
rRNA and t-RNA images from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved
mRNA image from http://wps.prenhall.com/wps/media/tmp/labeling/1140654_dyn.gif
RNA- the Other Nucleic Acid
NUCLEOTIDES
Also made of ___________
RIBOSE instead
Sugar is _______
of deoxyribose.
SINGLE stranded
RNA is _________
URACIL
Contains _________
instead
of thymine.
http://images2.clinicaltools.com/images/gene/dna_versus_rna_reversed.jpg
HOW CAN JUST 4 BASES GIVE DIRECTIONS
TO MAKE 20 AMINO ACIDS?
Message is read in groups of 3 = _________
CODON
UCGCACGGU
UCG-CAC-GGU
Serine - Histidine - Glycine
Codons represent different amino acids
Section 12-3
64 possible codons
Some amino acids
have more than one
codon.
AUG
START= _______
STOP
3 codons for _____
ANTICODON
___________
on tRNA
EACH tRNA
carries only
one kind of
amino acid
_____________
matches up with
CODON
________
on mRNA
Images modified from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved
Figure 12–18 Translation
Section 12-3
Figure 12–18 Translation (continued)
Section 12-3
Steps to Creating a Protein….
DNA
1._________unzips
Transcription
2.____________occurs
DNA
mRNA
- ________makes
______
Translation
3.____________occurs
mRNA
protein
- _______makes
a _______
REMEMBER: A PROTEIN IS A CHAIN OF AMINO ACIDS!
Bell Work
• What are the correct steps for protein
synthesis?
1. DNA Unzips
2. Transcription occurs
3. Translation occurs
• What is the name of the sugar in RNA?
– Ribose
MUTATIONS
Bell Work
• What are the 3 main ways DNA can become
mutated?
1. Mistakes made when copying your DNA
2. Exposure to radiation
3. Chemicals in the environment
REMEMBER!
_______________
MUTATIONS
are changes
in the genetic material.
Mutations can happen when cells make
mistakes
_____________
in copying their own DNA
radiation
or be caused by _______________
or
chemicals in the enviroment.
___________
KINDS OF MUTATIONS
Mutations that produce changes in a single
GENE MUTATIONS
gene = ______________________
Mutations that produce changes in whole
chromosomes =
CHROMOSOMAL MUTATIONS
_____________________
Bell Work
• How is DNA structured?
–
–
–
–
Double helix
Deoxyribose sugar
Sugar & Phosphate backbone
Nitrogen Bases
• Adenine = A bonds with Thymine = T
• Guanine = G bonds with Cytosine = C
– Double stranded
• How is RNA structured?
–
–
–
–
Single stranded
Ribose sugar
Sugar & Phosphate backbone
Nitrogen Bases
• Adenine = A bonds with Uracil = U
• Guanine = G bonds with Cytosine = C