View
16
Download
0
Category
Tags:
Preview:
DESCRIPTION
RNA. Say Hello to DNA’s little friend!. Engage. - PowerPoint PPT Presentation
Citation preview
Engage Essential Question Explain
Describe yourself to long lost uncle.
How do the mechanisms of genetics and the functions of nucleic acids give you the traits that make you who you are?
The steps and molecules involved in protein synthesis.
Engage
Your long lost uncle will be arriving at the airport this weekend and you are responsible for picking him up while everyone else finish preparing for the welcoming party at your house. Send your uncle a text with a description of yourself with enough detail for him to be able to recognize you among a large group of strange people.
Why do you look the way you do?
Each of your cells has the instructions needed to make you look, act and be who you are.
You just texted your uncle a list of your traits.
DNA is in your chromosomesYou inherited 23 chromosomes from each parent.
So your parents gave you your traits.
Each chromosome has segments of nucleotides called
genes.
Each gene has instructions; (DNA sequence = Genetic Code = Genome)
Humans have 23 pairs of chromosomes
Human Genome = all genes in humans = 30,000 – 40,000 genes
Each gene makes a protein for a specific trait
DNA is only the code
• RNA molecules make the actual workers that make you who you are.
• Proteins (polypeptides) are the biological workers that make you who you are.
Proteins are made up of amino acids
DiversityAll living things are made up of the same molecules:
DNA nucleotides
A = T
C = G
RNA nucleotides
A = U
C = G
20 amino acids (make up all possible proteins)
Is nicotine and alcohol addiction a trait coded by your genes?
• Students are sequencing genes related to nicotine addiction. Beginning in 2001, students are characterizing variation in the gene called CYP2A6, which codes for an enzyme involved in the excretion of nicotine. The student project has the potential for identifying new variants of this gene and ultimately contributing to our understanding of nicotine addition.
What is genetic variation and how is it related to drug addiction?
• Each of us is strongly aware of how we are different from everyone else our own uniqueness. People come in all different shapes, sizes, and colors, with a wide range of abilities, talents, and personalities. We even vary in the way we respond to drugs. What determines our characteristics, or traits? Our traits are determined by a variety of factors, including genetics, our environment, and our culture.
What genes are involved in nicotine addiction?
An exciting revelation of the Human Genome Project is how similar all human beings are on the genetic level we are all 99.9% the same! This means that a comparison of the DNA sequence of two individuals would reveal approximately one different nucleotide for every thousand nucleotides of sequence. Some of these nucleotide differences do not have any effect at all, while others change a particular genetic trait. In rare cases, differences in the nucleotide sequence can have extreme consequences for the individual, but usually they result in the subtle differences that make each of us unique.
How do we get the DNA sequence?
• Start reading from bottom of image and move up.
• Use circle or lines to help you keep track of bases.
• AAT TCC CGG GGA T…
The original CYP2A6 gene.
Read and write the
DNA sequence from the
gel electrophoresis picture.
3 types of RNA• mRNA – (messenger) -
copies DNA
• rRNA – (ribosomal) –
reads codons on mRNA
• tRNA – (transfer) – places amino acid on each codon of mRNA
DNA and RNA nucleotides
– Review
– New information
• DNA nucleotidesA = TG = C
• RNA nucleotidesA = U
(Uracil)G = C
RNA Differs from DNARNA Differs from DNA
1. RNA has a sugar ribose2. RNA contains the base uracil (U) (A=U C=G)3. RNA molecule is single-stranded4. In the nucleus
RNARNA DNADNA
1. DNA has a sugar deoxyribose2. DNA has thymine (T) (A=T C=G)3. DNA is double-stranded4. Leaves the nucleus goes to ribosome
Make a T Chart!!!
TranscriptionT
• DNA is copied by mRNA
• Occurs in nucleus
• mRNA leaves nucleus with instructions to make a protein.
• mRNA finds a ribosome in cytoplasm or on rough endoplasmic reticulum
Translation
• rRNA (in ribosome) reads nucleotides on mRNA
• 3 nucleotides on mRNA = 1codon
• 1 codon = 1 amino acid
Translation
• tRNA brings the amino acid to each codon
• Amino acids form long chains called polypeptides or proteins
Practice
DNA – TAC CAG ATC ATT
mRNA - AUG ___ ___ __
a.a. - met ___ ___ ___
1. Transcribe DNA into mRNA
2. Translate mRNA into amino acid chain.
alanine – alaarginine – argasparagine – asnaspartic acid – aspcysteine – cysglutamine – glnglutamic acid – gluglycine – glyhistidine – hisisoleucine – ileleucine – leulysine – lysmethionine – metphenylalanine – pheproline – proserine – serthreonine – thrtryptophan – trptyrosine – tyr valine – val
1. Explain the process and molecules involved in protein synthesis.
2. Why is RNA, DNA’s “little friend”?
Complete amino acid chain for original CYP2A6 gene
• Go to your DNA sequence of the original CYP2A6 gene.
• Transcribe DNA sequence into mRNA.
• Translate mRNA into amino acid chain.
• Next transcribe and translate the DNA sequence of 5 variant genes for CYP2A6.
Molecule Gene Name* variant
Sequence: separate each codon on mRNA with / in between circle each amino acid
DNA CYP2A6*2 TAC GCG GGC TTC CTC ATG GAC GCC CAC CGG GGC ACT
mRNA AUG /CGC/CCG/ AAG/ GAG/ / / / / / / STOP
a.a. MET ARG PRO ARG GLU
DNA CYP2A6*5 TAC CAA AGT CAC CTA AGG ACA TTG ACG TGT CCC AAC ATT
mRNA AUG/ / / / / / / / / / / / /
a.a.
DNA CYP2A6*6 TAC TAT TCA GCA ACG GGG AGC GCG CCA AGC AGC TCC ATC
mRNA / / / / / / / / / / / / /
a.a.
DNA CYP2A6*7 TAC AGT AGT CAC CTA AGG ACA CTG ACG TGT CCC CCA ACT
mRNA / / / / / / / / / / / / /
a.a.
DNA CYP2A6*8 TAC TTT CCA CTA AAC TAA ACC ATG AGC TTC CTG CCC ATT
mRNA
a.a.
Explain
• The steps and molecules involved in protein synthesis.
• Use labeled diagrams to help your explanation.
Essential QuestionHow do the mechanisms of genetics and
functions of nucleic acids give you the traits that make you who you are?
• Use the example of the nicotine addiction gene to construct your answer.
• Did changes in DNA of variant genes affect the protein being made?
• How do you know?
Use a ruler or straight edge to read the order of DNA nucleotides.Start at the bottom of picture of the gel.You can use circles, highlighter or lines to group them into 3’s.
DNA AAT TCC CGG G…
mRNA
Amino acid
DNA
mRNA
Amino acid
DNA
mRNA
Amino acid
DNA
mRNA
Amino acid
Molecule Gene Name* variant
Sequence: separate each codon on mRNA with / in between circle each amino acid
DNA CYP2A6*2 TAC GCG GGC TTC CTC ATG GAC GCC CAC CGG GGC ACT
mRNA AUG /CGC/CCG/ AAG/ GAG/ / / / / / / STOP
a.a. MET ARG PRO ARG GLU
DNA CYP2A6*5 TAC CAA AGT CAC CTA AGG ACA TTG ACG TGT CCC AAC ATT
mRNA AUG/ / / / / / / / / / / / /
a.a.
DNA CYP2A6*6 TAC TAT TCA GCA ACG GGG AGC GCG CCA AGC AGC TCC ATC
mRNA / / / / / / / / / / / / /
a.a.
DNA CYP2A6*7 TAC AGT AGT CAC CTA AGG ACA CTG ACG TGT CCC CCA ACT
mRNA / / / / / / / / / / / / /
a.a.
DNA CYP2A6*8 TAC TTT CCA CTA AAC TAA ACC ATG AGC TTC CTG CCC ATT
mRNA
a.a.
ala
nin
e –
ala
arg
inin
e –
arg
as
pa
rag
ine
– a
sn
as
pa
rtic a
cid
– a
sp
cy
ste
ine
– c
ys
glu
tam
ine
– g
lng
luta
mic
ac
id –
glu
gly
cin
e –
gly
his
tidin
e –
his
iso
leu
cin
e –
ilele
uc
ine
– le
uly
sin
e –
lys
me
thio
nin
e –
me
tp
he
ny
lala
nin
e –
ph
ep
rolin
e –
pro
se
rine
– s
er
thre
on
ine
– th
rtry
pto
ph
an
– trp
tyro
sin
e –
tyr
va
line
– v
al
Recommended