DNA, RNA, Mutations
Dec 16, 2015
DNA, RNA, Mutations
Objective 2: 6a,b,c Biology: DNA, RNA, Mutation
The student knows the structures and functions of nucleic acids in the mechanisms of genetics. The student is expected to:
• (A) describe components of deoxyribonucleic acid (DNA), and illustrate how information for specifying the traits of an organism is carried in the DNA;
• (B) explain replication, transcription, and translation using models of DNA and ribonucleic acid (RNA);
• (C) identify and illustrate how changes in DNA cause mutations and evaluate the significance of these changes
Remember THIS?
Making a DNA copy of DNA is replication. Cells need to copy their DNA for mitosis (growth, repair, and maintenance). Daughter cells are genetically identical. DNA is also copied for meiosis (reproduction). Daughter cells are genetically different and have ½ the # of chromosomes.
C
P
D
C
P
D
C
P
D
P
D
G
P
D
GP
D T
P
DA
P
DT
P
D A
P
D
G
NitrogenBase
Phosphate group
Deoxy-ribose
DNA is made of building blocks called nucleotides. They consist of a deoxyribose sugar, a phosphate group and a nitrogen base. The bases are adenine, thymine, guanine, and cytosine.
RNA is made of building blocks called nucleotides.
They consist of a ribose sugar (instead of a
deoxyribose sugar), a phosphate group and a
nitrogen base. The bases are adenine, uracil,
guanine, and cytosine.
NitrogenBase
Phosphate group
ribose
DNA RNA
Both have adenine, guanine, and cytosine as bases
Has the base thymine
Has the base uracil
Both have a sugar phosphate backbone.
Sugar: Deoxyribose Sugar: ribose
There are three types of RNA:
mRNA-messenger (transcribes DNA)
tRNA-transfer (translates mRNA)
rRNA-ribosomal (used as a machine for translation)
REPLICATION : DNA copies DNA A T G C
http://www.johnkyrk.com/DNAreplication.html http://nobelprize.org/chemistry/educational/dna/b/replication/dna_compounds.html
TRANSCRIPTION: mRNA copies DNAA U G C T A
http://www.johnkyrk.com/DNAtranscription.html
TRANSLATION: mRNA is decoded and a protein is made from amino acids. A UG C
http://www.johnkyrk.com/DNAtranslation.html
MUTATION: Any change in the DNA sequence. If it is a point mutation (one letter is changed), it can change the amino acid sequence by changing the code.
Deletion
ATC ATG
Point mutation
Transcription
Translation
DNA mRNA ProteinIn nucleus On ribosome
Let’s try it:
1. Write this DNA base pair sequence on you paper.
2. Write the complementary strand of DNA that would bond to them.
3. Translate the strand into mRNA.
4. List the amino acids that these codons stand for. Use the amino acid chart on the next slide.
ATGTGGCAG
A-T-G-T-G-G-C-A-G-
Complementary strand that would form in Replication.
TACA
C
C
C
GT
T-A-C-A-C-C-G-T-C-
AUGUGGCAG
DNA mRNA Amino Acids
Methionine
Tryptophan
Glutamine
Transcription Translation
Peptide Bonds
ATGCCATTCAATTAACCCTCC
1. Write this DNA base pair sequence on you paper.
2. Write the complementary strand of DNA that would bond to them.
3. Translate the strand into mRNA.
4. List the amino acids that these codons stand for.
DNA Original Strand
ATG CCA TTC AAT TAA CCC TCC
DNA Replicated Strand
TAC GGT AAG TTA ATT GGG AGG
mRNA AUG CCA UUC AAU UAA CCC TCC
Amino Acids
Met Pro Phen Asp Stop
DNA Simulation
http://www.johnkyrk.com/DNAanatomy.html
Interactive DNA Workshop
http://www.pbs.org/wgbh/aso/tryit/dna/index.html