Chapter 3
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Transcript of Chapter 3
Chapter 3
A. Gene function
Genes and protein synthesis and mutation(diagram)
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)
How proteins are made (protein synthesis):
tRNA
RNA Polymerase ribosomes (protein, rRNA)
DNA mRNA protein4 "letters” 4 "letters” 20 "letters"
transcription translation(in nucleus) (in cytoplasm)
What is a “gene?”
the DNA from a part of a chromosome that “codes” for a particular product (protein)
Chromosomes have from50 -250 Mb (Megabytes) of nucleotides50,000,000 to 250,000,000
nucleotides
a chromosome
double helix
Review DNA Replication
• DNA is double stranded• Base pairing between strands
A = TC G
Thymine
Adenine
Cytosine
Guanine
Review DNA Replication
• DNA is unwound
• DNA Polymerase finds compliment to each nucleotide and makes new strands
• Two identical molecules of DNA
Review DNA info
nucleic aciddouble-strandedfour nucleotides
A, C, G, Tbase-pairing
RNA info
nucleic acidsingle-strandedfour nucleotides
A, C, G, Ubase-pairing
Protein synthesis (A)•Unwind DNA
•Make strand of RNA complimentary to one DNA strand
•RNA Polymerase is the enzyme
Protein synthesis
Fig 25.8
Protein synthesis (A)
Fig 25.8
•RNA produced is call mRNA (messenger)•It is produced in the nucleus•The information has been re-written
from one nucleic acid “dialect” (DNA) toanother (RNA)
•Process is called transcription
C. How proteins are made (protein synthesis):
tRNA
RNA Polymerase ribosomes (protein, rRNA)
DNA mRNA protein4 "letters” 4 "letters” 20 "letters"
transcription translation
(in nucleus) (in cytoplasm)
Protein synthesis (B)
Fig 25.8
•mRNA is moved to the cytoplasm•It will bind to the ribosome
proteins rRNA (ribosomal RNA)
Remember where the ribosomes are ?
Protein synthesis (B)
Fig 25.8
•tRNAcarriesamino acid
hasanticodon
Protein synthesis (B)
Fig 25.8
•tRNAcarriesamino acid
hasanticodon
Fig 25.10
Protein synthesis (B)
Fig 25.8
•tRNA
The tRNA with a particular anticodon (GCU) will always carry the same amino acid.
(Complimentary codon is. . .
Protein synthesis (B)
Fig 25.8
•tRNA
The tRNA with a particular anticodon (GCU) will always carry the same amino acid.
(Complimentary codon is CGA
Protein synthesis (B)
Fig 25.8
Fig 25.6
mRNAsequence
Protein synthesis (B)
Fig 25.8
•mRNA is moved to the cytoplasm•It will bind to the ribosome
proteins rRNA (ribosomal RNA)
Fig 25.12
Protein synthesis (B)
Fig 25.8
Fig 25.6
mRNAsequence
Protein synthesis (B)
Fig 25.8
•mRNA is moved to the cytoplasm•It will bind to the ribosome
proteins rRNA (ribosomal RNA)
Fig 25.12
Fig 25.8Fig 25.12
Fig 25.8Fig 25.12
fig. 3-1
fig. 3-3
fig. 3-4
fig. 3-5
Review Outline 2C. How proteins are made (protein synthesis):
tRNA
RNA Polymerase ribosomes (protein, rRNA)
DNA mRNA protein4 "letters” 4 "letters” 20 "letters"
transcription translation
(in nucleus) (in cytoplasm)
Fig 25.8
Fig 25.6
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
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
Everybody gets an job or identity
Enzymes (2) (make polymers)
DNA nucleotide (A=T; C=G)
RNA nucleotide (A=U;C=G)
tRNA (find and carry your amino acid)
Amino acid (sit there and look pretty)
Fig 25.8
Fig 25.6
Everybody gets an job or identity
Enzymes (2) (make polymers)
DNA nucleotide (A=T; C=G)
RNA nucleotide (A=U;C=G)
tRNA (find and carry your amino acid)
Thymine
Adenine
Cytosine
Guanine
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)
Identification of genes
pedigrees
Identification of genes
pedigrees
fig 3-7
DNA markersUnique place on a chromosome that can be detected with a probe.
DNA markersUnique place on a chromosome that can be detected with a probe.
Follow different DNA markers that fit the pedigree
Pedigree =
=
Pedigree = disease
= normal
Analysis ?
Define terms
Define terms:
N = normal
n = diseased (e.g., CF)
nn nn
nn nn
N_
N_ N_
N_ N_N_N_
nn nn
N?
N_ N_
N_ N_N_N?
nn nn
Nn
N_ N_
N_ N_N_Nn
nn nn
Nn
N? N?
N_ N_N_Nn
nn nn
Nn
N? N?
N_ N_N_Nn
8 yrs
Kirstin
10 yrs
Courtney
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)
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
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
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
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
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
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
fig 3-10
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
Autosomal Dominant Diseases
• Huntington Disease• Myotonic Dystrophy
Autosomal Dominant Diseases
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)
X-linked recessive
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)
Chapter 3
C. Use/Misuse of genetic information
Genetic tests
Prenatal testing
PCR (polymerase chain reaction)Eugenics (positive/negative)
Chapter 3
C. Use/Misuse of genetic information
Genetic tests ?
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 (it’s expensive)?
Chapter 3
C. Use/Misuse of genetic information
Genetic tests
Prenatal testing
Amniocentesis
Chorionic villi sampling
PCR (polymerase chain reaction)Eugenics (positive/negative)
Fig 3-11
fig 3-11
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)
Chapter 3
C. Use/Misuse of genetic information
Genetic tests
Prenatal testing
PCR (polymerase chain reaction)
a technique used to examine very small samples
fig 3-12
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)
Eugenics“good birth”
Individuals have genetic identity genotype
Populations have genetic identity gene pool
Eugenics is working to change the gene pool
Positive use the “best” to breed (cattle, plants)
Negative prevent “inferior” genes from passing on
Eugenics“good birth”
Individuals have genetic identity genotype
Populations have genetic identity gene pool
Eugenics is working to change the gene pool
Positive use the “best” to breed (cattle, plants)
Negative prevent “inferior” genes from passing on
Eugenics“good birth”
Individuals have genetic identity genotype
Populations have genetic identity gene pool
Eugenics is working to change the gene pool
Is it right?