A.Gene function

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Chapter 3
A. Gene function Genes and protein synthesis and
mutation (diagram) B. Genetic diseases Identificat
ion of genes Pedigrees/DNA markers Diseases
(PKU, Albinism, CF, Huntington Disease,
DMD) C. Use/Misuse of genetic information Genetic
tests Prenatal testing PCR (polymnerase chain
reaction) Eugenics (positive/negative)
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• How proteins are made (protein synthesis)
• tRNA
• RNA Polymerase ribosomes (protein,
  rRNA)
• DNA mRNA protein
• 4 "letters 4 "letters 20 "letters"
• transcription translation
• (in nucleus) (in cytoplasm)

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What is a gene?
the DNA from a part of a chromosome that codes
for a particular product (protein)
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double helix
nucleotides
a chromosome
Chromosomes have from 50 -250 Mb (Megabytes) of
nucleotides 50,000,000 to 250,000,000
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Review DNA Replication

• DNA is double stranded
• Base pairing between strands
• A T
• C G

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Thymine
Cytosine
Adenine
Guanine
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Review DNA Replication

• DNA is unwound
• DNA Polymerase finds compliment to each
  nucleotide and makes new strands
• Two identical molecules of DNA

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Review DNA info
RNA info
nucleic acid double-stranded four nucleotides A,
C, G, T base-pairing
nucleic acid single-stranded four nucleotides A,
C, G, U base-pairing
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Protein synthesis (A)

• Unwind DNA
• Make strand of RNA complimentary to one DNA
  strand
• RNA Polymerase is the enzyme

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Protein synthesis
Fig 25.8
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Protein synthesis (A)

• RNA produced is call mRNA (messenger)
• It is produced in the nucleus
• The information has been re-written
• from one nucleic acid dialect (DNA) to
• another (RNA)
• Process is called transcription

Fig 25.8
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• How proteins are made (protein synthesis)
• tRNA
• RNA Polymerase ribosomes (protein,
  rRNA)
• DNA mRNA protein
• 4 "letters 4 "letters 20 "letters"
• transcription translation
• (in nucleus) (in cytoplasm)

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Protein synthesis (B)

• mRNA is moved to the cytoplasm
• It will bind to the ribosome
• proteins
• rRNA (ribosomal RNA)
• Remember where the ribosomes are ?

Fig 25.8
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Protein synthesis (B)

• tRNA
• carries
• amino acid
• has
• anticodon

Fig 25.8
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Protein synthesis (B)

• tRNA
• carries
• amino acid
• has
• anticodon

Fig 25.10
Fig 25.8
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Protein synthesis (B)

• tRNA
• The tRNA with a particular anticodon (GCU) will
  always carry the same amino acid.

(Complimentary codon is. . .
Fig 25.8
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Protein synthesis (B)

• tRNA
• The tRNA with a particular anticodon (GCU) will
  always carry the same amino acid.

(Complimentary codon is CGA
Fig 25.8
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Protein synthesis (B)
mRNA sequence
Fig 25.8
Fig 25.6
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Protein synthesis (B)

• mRNA is moved to the cytoplasm
• It will bind to the ribosome
• proteins
• rRNA (ribosomal RNA)

Fig 25.12
Fig 25.8
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Protein synthesis (B)
mRNA sequence
Fig 25.8
Fig 25.6
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Protein synthesis (B)

• mRNA is moved to the cytoplasm
• It will bind to the ribosome
• proteins
• rRNA (ribosomal RNA)

Fig 25.12
Fig 25.8
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Fig 25.12
Fig 25.8
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Fig 25.12
Fig 25.8
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fig. 3-1
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fig. 3-3
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fig. 3-4
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fig. 3-5
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Review Outline 2

• How proteins are made (protein synthesis)
• tRNA
• RNA Polymerase ribosomes (protein,
  rRNA)
• DNA mRNA protein
• 4 "letters 4 "letters 20 "letters"
• transcription translation
• (in nucleus) (in cytoplasm)

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If you know the DNA sequence, you can determine
the mRNA sequence and can determine what order
the amino acids will be arranged in the
protein
Fig 25.8
Fig 25.6
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If you know the DNA sequence, you can determine
the mRNA sequence and can determine what order
the amino acids will be arranged in the
protein so lets make some hemoglobin.
Fig 25.8
Fig 25.6
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Everybody gets an job or identity Enzymes (2)
(make polymers) DNA nucleotide (AT CG) RNA
nucleotide (AU CG) tRNA (find and carry your
amino acid) Amino acid (sit there and look
pretty)
Fig 25.8
Fig 25.6
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Everybody gets an job or identity Enzymes (2)
(make polymers) DNA nucleotide (AT CG) RNA
nucleotide (AU CG) tRNA (find and carry your
amino acid)
Fig 25.8
Fig 25.6
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Thymine
Cytosine
Adenine
Guanine
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Chapter 3
A. Gene function Genes and protein synthesis and
mutation B. Genetic diseases Identification of
genes Pedigrees/DNA markers Diseases (PKU,
Albinism, CF, Huntington Disease,
DMD) C. Use/Misuse of genetic information Genetic
tests Prenatal testing PCR (polymnerase chain
reaction) Eugenics (positive/negative)
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Identification of genes pedigrees
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Identification of genes pedigrees
fig 3-7
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DNA markers Unique place on a chromosome that can
be detected with a probe.
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DNA markers Unique place on a chromosome that can
be detected with a probe. Follow different DNA
markers that fit the pedigree
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• Pedigree

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• Pedigree
• disease
• normal

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Analysis ? Define terms
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Define terms N normal n diseased (e.g., CF)
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nn
nn
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N_
N_
N_
N_
N_
N_
N_
nn
nn
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N_
N_
N?
N?
N_
N_
N_
nn
nn
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N_
N_
Nn
Nn
N_
N_
N_
nn
nn
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N?
N?
Nn
Nn
N_
N_
N_
nn
nn
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N?
N?
Nn
Nn
N_
N_
N_
nn
nn
10 yrs Courtney
8 yrs Kirstin
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Chapter 3
A. Gene function Genes and protein synthesis and
mutation B. Genetic diseases Identification of
genes Pedigrees/DNA markers Diseases (PKU,
Albinism, CF, Huntington Disease,
DMD) C. Use/Misuse of genetic information Genetic
tests Prenatal testing PCR (polymnerase chain
reaction) Eugenics (positive/negative)
54
B. Genetic diseases Diseases (PKU, Albinism,
CF, Huntington Disease, DMD)
autosomal recessive human diseases autosomal -
on chromosomes 1-22 (not on X or Y) recessive -
not dominant
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B. Genetic diseases Diseases (PKU, Albinism,
CF, Huntington Disease, DMD)
autosomal recessive human diseases autosomal -
on chromosomes 1-22 (not on X or Y) recessive -
not dominant
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B. Genetic diseases Diseases (PKU, Albinism,
CF, Huntington Disease, DMD)
autosomal recessive human diseases autosomal -
on chromosomes 1-22 (not on X or Y) recessive -
not dominant
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B. Genetic diseases Diseases (PKU, Albinism,
CF, Huntington Disease, DMD)
autosomal recessive human diseases CF cystic
fibrosis chromosome 7 defective chloride
transport protein PKU defective enzyme to
breakdown phenyalanine
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B. Genetic diseases Diseases (PKU, Albinism,
CF, Huntington Disease, DMD)
autosomal recessive human diseases CF cystic
fibrosis chromosome 7 defective chloride
transport protein PKU defective enzyme to
breakdown phenyalanine
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B. Genetic diseases Diseases (PKU, Albinism,
CF, Huntington Disease, DMD)
autosomal recessive human diseases CF cystic
fibrosis chromosome 7 defective chloride
transport protein PKU defective enzyme to
breakdown phenyalanine Albinism defective enzyme
for making pigment
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fig 3-10
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B. Genetic diseases Diseases (PKU, Albinism,
CF, Huntington Disease, DMD)
autosomal recessive human diseases CF cystic
fibrosis chromosome 7 defective chloride
transport protein PKU defective enzyme to
breakdown phenyalanine Albinism defective enzyme
for making pigment Tay Sachs missing Hex A
enzyme, ganglioside accumulates
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Autosomal Dominant Diseases

• Huntington Disease
• Myotonic Dystrophy

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Autosomal Dominant Diseases
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Chapter 3
A. Gene function Genes and protein synthesis and
mutation B. Genetic diseases Identification of
genes Pedigrees/DNA markers Diseases (PKU,
Albinism, CF, Huntington Disease,
DMD) C. Use/Misuse of genetic information Genetic
tests Prenatal testing PCR (polymnerase chain
reaction) Eugenics (positive/negative)
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X-linked recessive
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Chapter 3
A. Gene function Genes and protein synthesis and
mutation B. Genetic diseases Identification of
genes Pedigrees/DNA markers Diseases (PKU,
Albinism, CF, Huntington Disease,
DMD) C. Use/Misuse of genetic information Genetic
tests Prenatal testing PCR (polymnerase chain
reaction) Eugenics (positive/negative)
68
Chapter 3
C. Use/Misuse of genetic information Genetic
tests Prenatal testing PCR (polymerase chain
reaction) Eugenics (positive/negative)
69
Chapter 3
C. Use/Misuse of genetic information Genetic
tests ?
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Chapter 3
C. Use/Misuse of genetic information Genetic
tests It is possible to test for many different
genetic diseases. Is it right to do so? Who
pays (its expensive)?
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Chapter 3
C. Use/Misuse of genetic information Genetic
tests Prenatal testing Amniocentesis Chorionic
villi sampling PCR (polymerase chain
reaction) Eugenics (positive/negative)
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Fig 3-11
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fig 3-11
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Chapter 3
C. Use/Misuse of genetic information Genetic
tests Prenatal testing If you found out an
unborn child had a genetic disease what would you
do? PCR (polymerase chain reaction) Eugenics
(positive/negative)
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Chapter 3
C. Use/Misuse of genetic information Genetic
tests Prenatal testing PCR (polymerase chain
reaction) a technique used to examine very
small samples
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fig 3-12
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Chapter 3
A. Gene function Genes and protein synthesis and
mutation B. Genetic diseases Identification of
genes Pedigrees/DNA markers Diseases (PKU,
Albinism, CF, Huntington Disease,
DMD) C. Use/Misuse of genetic information Genetic
tests Prenatal testing PCR (polymnerase chain
reaction) Eugenics (positive/negative)
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Eugenics good birth
Individuals have genetic identity genotype Popula
tions have genetic identity gene pool Eugenics
is working to change the gene pool Positive use
the best to breed (cattle, plants) Negative pre
vent inferior genes from passing on
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Eugenics good birth
Individuals have genetic identity genotype Popula
tions have genetic identity gene pool Eugenics
is working to change the gene pool Positive use
the best to breed (cattle, plants) Negative pre
vent inferior genes from passing on
80
Eugenics good birth
Individuals have genetic identity genotype Popula
tions have genetic identity gene pool Eugenics
is working to change the gene pool Is it right?