mrs. stewart biology i honors
DESCRIPTION
DNA Structure. Mrs. Stewart Biology I Honors. STANDARDS:. CLE 3210.4.1Investigate how genetic information is encoded in nucleic acids. CLE 3210.4.2Describe the relationships among genes, chromosomes, proteins, and hereditary traits. OBJECTIVES: (today, I will…). - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/1.jpg)
Mrs. StewartBiology I Honors
DNAStructur
e
![Page 2: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/2.jpg)
STANDARDS:CLE 3210.4.1 Investigate how
genetic information is encoded in nucleic acids.
CLE 3210.4.2 Describe the relationships among genes, chromosomes, proteins, and hereditary traits.
![Page 3: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/3.jpg)
OBJECTIVES: (today, I will…)Evaluate the structure of nucleic
acids Determine how genetic information is
“coded” in nucleic acids Create complementary DNA strands
using Chargaff’s rule
![Page 4: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/4.jpg)
Nucleic AcidsMacromolecules containing :
Carbon HydrogenOxygenNitrogenPhosphorus
Function: Store and transmit genetic/hereditary information
![Page 5: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/5.jpg)
Two types of Nucleic Acids
DNARNA
![Page 6: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/6.jpg)
DNA Stands for:
Deoxyribonucleic Acid
![Page 7: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/7.jpg)
DNA StructureDNA is made up of two strands that are
arranged into a twisted, ladder-like structure called a Double Helix.
A strand of DNA is made up of millions of tiny subunits called Nucleotides.
Each nucleotide consists of 3 parts:1. Phosphate group2. sugar3. Nitrogenous base
![Page 8: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/8.jpg)
Nucleotides
Phosphate
Pentose
Sugar
Nitrogenous
Base
![Page 9: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/9.jpg)
DNA sugarThe 5 carbon sugar for DNA is
Deoxyribose
That is where the name (Deoxyribo)nucleic acid comes from
![Page 10: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/10.jpg)
NucleotidesThe phosphate and sugar form the
backbone of the DNA molecule, whereas the bases form the “rungs”.
There are four types of nitrogenous bases.
![Page 11: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/11.jpg)
4 different Nitrogen bases
A
AdenineT
Thymine
G
GuanineC
Cytosine
![Page 12: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/12.jpg)
Purines
A
Adenine
G
Guanine
![Page 13: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/13.jpg)
Pyrimidines
T
Thymine
C
Cytosine
![Page 14: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/14.jpg)
Chargaff’s ruleErwin Chargaff observed that the
percentage of adenine equals the percentage of thymine, and the percentage of cytosine equals the percentage of guanine.
Example: in one strand of DNA the following amounts may be found:15% Adenine15% Thymine35% Cytosine35% Guanine
![Page 15: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/15.jpg)
Complementary base pairing:Each base will only bond with one
other specific base. (Chargaff’s rule)
Adenine (A)Thymine (T)
Cytosine (C)Guanine (G)
Form a base pair.
Form a base pair.
![Page 16: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/16.jpg)
DNA StructureBecause of this complementary base
pairing, the order of the bases in one strand determines the order of the bases in the other strand.
![Page 17: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/17.jpg)
G
G
A
T
T
A
A
C
T
G
C
A
T
C
![Page 18: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/18.jpg)
Practice:Complete the complementary DNA strand for
the following sequence:
G T A A C T C C TC A T A G A G G A
C T C C T A A A CG A G G A T T T G
T A G A A T G C CA T C T T A C G G
![Page 19: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/19.jpg)
DNA StructureTo crack the genetic code found in
DNA we need to look at the sequence of bases.
The bases are arranged in triplets (sets of 3) called codons.
A G G - C T C - A A G - T C C - T A GT C C - G A G - T T C - A G G - A T C
![Page 20: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/20.jpg)
DNA StructureA gene is a section of DNA that codes for a
protein.
Each unique gene has a unique sequence of bases.
This unique sequence of bases will code for the production of a unique protein.
It is these proteins and combination of proteins that give us a unique phenotype.
![Page 21: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/21.jpg)
Protein
DNAGene
Trait
![Page 22: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/22.jpg)
Your TaskDraw a flow chart to
show how to get from:
![Page 23: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/23.jpg)
Mrs. StewartBiology I Honors
DNA Replicati
on
![Page 24: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/24.jpg)
STANDARDS:CLE 3210.4.1 Investigate how
genetic information is encoded in nucleic acids.
CLE 3210.4.2 Describe the relationships among genes, chromosomes, proteins, and hereditary traits.
![Page 25: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/25.jpg)
OBJECTIVES: (today, I will…)Evaluate the structure of DNA and
the need for replicationCreate complementary DNA strands
to simulate replication
![Page 26: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/26.jpg)
DNA Double HelixMade of 2 strands of nucleotidesThese strands are joined together with the pairing of the Nitrogen bases(A, T, C, G)
The bases are joined by Hydrogen bonds
![Page 27: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/27.jpg)
Think – Pair - ShareLook at the picture and try to figure
out what “antiparallel” means.
Did you notice that the strands of DNA run in “opposite directions”?
![Page 28: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/28.jpg)
5’ and 3’ ends of DNARefers to the orientation
of the carbon atoms on the deoxyribose
Strands run in opposite directions
One strand is “upside down”
![Page 29: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/29.jpg)
Think – pair - shareWhy does DNA need to replicate
itself?
![Page 30: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/30.jpg)
DNA ReplicationDNA makes an exact copy of itselfOccurs during the S stage of
interphase
![Page 31: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/31.jpg)
Semi-conservativeEach strand of the double
helix will serve as a template for the new strands that will form
End result is two complete DNA double helixes – each containing one strand from the original molecule and one newly made complementary strand
![Page 32: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/32.jpg)
HelicaseEnzyme that “unzips” the
DNA double helix by breaking the Hydrogen bonds between the bases to separate the strands in preparation for replication
Creates a “replication fork”
![Page 33: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/33.jpg)
DNA PolymeraseUses “free-floating” nucleotides in the nucleus to build the complementary strand of DNA
![Page 34: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/34.jpg)
5‘ to 3‘ directionThe new DNA strands need to form in
the 5 prime to 3 prime direction.
Leading strand: forms continuously because it is forming in the 5’ to 3’ direction
Lagging strand: forms in short segments called Okazaki fragments, so that it can also form in the 5’ to 3’ direction
![Page 35: Mrs. Stewart Biology I Honors](https://reader036.vdocuments.us/reader036/viewer/2022062501/56815f94550346895dce98cb/html5/thumbnails/35.jpg)
Animation of replication #1Animation of replication #2