HOW TO READ YOUR DNA
OR
PROTEIN SYNTHESIS
LEARNING TARGETS:
1.
2.
3.
4.
5.
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7.
I can explain the relationship of DNA to proteins.
I can summarize the process of protein synthesis.
I can compare and contrast the structure of RNA to
DNA
I can identify and explain the functions of the three
types of RNA
I can describe the process of transcription
I can describe the process of translation
I can identify and explain Frameshift and
Substitution mutations.
THE PURPOSE OF DNA
DNA
stores
instructions
for making
proteins.
HOW TO
MAKE
PROTEIN

EVERYTHING in your body is made of protein!





Your skin
Your hair
Your eyes
Your blood
Your personality
STOP! YOU SHOULD BE ABLE TO ANSWER:
1.
I can explain the relationship of
DNA to proteins.
OVERVIEW
The
instructions are written using a
four-letter alphabet - A, T, C, G
The instructions are “translated” into
mRNA using the four-letter alphabet –
A, U, C, G
 Each
3-letter group makes a “word” or
CODON
 Every
mRNA “word” codes an amino
acid.
 Amino acids are strung together to
form proteins.
 Most proteins have about 200-300
amino acids held together by peptide
bonds!
THE CENTRAL DOGMA
DNA
mRNA
Proteins
STOP! YOU SHOULD BE ABLE TO ANSWER:
2.
I can summarize the process of protein
synthesis.
RNA
Single
Helix
Uracil instead
of Thymine
Ribose sugar
instead of
Deoxyribose
sugar
RNA DOES NOT HAVE THYMINE!
A–U
C–G
STOP! YOU SHOULD BE ABLE TO ANSWER:
3.
I can compare and contrast the structure of
RNA to DNA
THREE KINDS OF RNA
1.
Messenger RNA (mRNA) – reads and copies the
DNA and takes it to the ribosome.
This is called Transcription
THREE KINDS OF RNA
2. Transfer RNA (tRNA) – translates every three
letters into a word, or codon, and builds amino
acids.
This is called Translation
THREE KINDS OF RNA
3. rRNA - Ribosomes are made out of
rRNA. They string the amino acids
together to make polypeptides.
A polypeptide is a chain of two or more
amino acids
STOP! YOU SHOULD BE ABLE TO ANSWER:
1.
I can identify and explain the functions
of the three types of RNA
TRANSCRIPTION

Decoding DNA into mRNA
Step 1:
An enzyme called
RNA polymerase
unzips the DNA
Step 2:
mRNA
nucleotides
match up
with one
side of the
“unzipped”
DNA
RNA nucleotide
Step 3:
mRNA
goes to
the
ribosome
mRNA strand
One side of DNA strand
Step 4: The DNA
“zips”
back together
STOP! YOU SHOULD BE ABLE TO ANSWER:
1.
I can describe the process of transcription
TRANSLATION

Decoding the mRNA into Proteins
TRANSLATION
tRNA
translates
the
codons on the
mRNA into
anti-codons
in the
ribosome
TRANSLATION
Three
bases (one codon)
make one amino acid.
There are 20 amino acids.
There are 64 codons
How Can This Be???
STOP! YOU SHOULD BE ABLE TO ANSWER:
1.
I can describe the process of translation
Mutations
MUTATION
A change in the base sequence of
DNA. May be good or bad.
1. Gene mutation – a base gets
substituted (silent and non-silent),
deleted, or inserted.
INSERTIONS AND DELETIONS ARE CALLED
FRAMESHIFT MUTATIONS
THE BIG FAT CAT ATE THE RAT AND GOT ILL
Deletion of one base
THE IGF ATC ATA TET HER ATA NDG OTI LL
Mutagenic Agent – substance that
causes the addition, removal, or
substitution of a nitrogenous base.
Inherited Mutation – passed on to
offspring.
1. Sickle Cell Anemia – A is replaced
by T in hemoglobin gene
2. Cystic fibrosis – normal codon
replaced by “stop” codon
3. Tay-Sachs Disease – base insertion
on chromosome 15
Somatic Mutation – not passed on to
offspring.
1. Lung cancer – tobacco and asbestos
2. Skin cancer – radiation
3. One blue and one brown eye –
random mutation after birth
STOP! YOU SHOULD BE ABLE TO ANSWER:
1.
I can identify and explain
Frameshift and Substitution
mutations.