Review: DNA? RNA? Protein

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Review DNA? RNA? Protein

• In a cell, genetic information flows from DNA to
  RNA in the nucleus and RNA to protein at the
  ribosome.

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RNA polymerase
Transcription
Nucleus
DNA
mRNA
Intron
Figure 10.20-1
3
RNA polymerase
Transcription
Nucleus
DNA
mRNA
Intron
RNA processing
Cap
Tail
mRNA
Intron
Amino acid
Ribosomal subunits
tRNA
Enzyme
ATP
Initiation of translation
Amino acid attachment
Figure 10.20-4
4
RNA polymerase
Transcription
Polypeptide
Nucleus
DNA
Stop codon
mRNA
Intron
RNA processing
Cap
Termination
Tail
mRNA
Intron
Anticodon
Amino acid
Ribosomal subunits
Codon
tRNA
Enzyme
Elongation
ATP
Initiation of translation
Amino acid attachment
Figure 10.20-6
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• Transcription and translation are how genes
  control
• The structures
• The activities of cells

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Mutations

• A mutation is any change in the nucleotide
  sequence of DNA.
• Mutations can change the amino acids in a
  protein.
• Mutations can involve
• Large regions of a chromosome
• Just a single nucleotide pair, as occurs in
  sickle cell anemia

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• How can Mutations be BAD?

• How can Mutations be GOOD?

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• Although mutations are often harmful, they are
  the source of genetic diversity, which is
  necessary for evolution by natural selection.

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Mutagens

• Mutations may result from
• Errors in DNA replication
• Physical or chemical agents called mutagens
• UV rays, X-rays, gamma rays, chemicals

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Types of Mutations

• Mutations within a gene can occur as a result of
• Nucleotide substitution, the replacement of one
  nucleotide by another
• Nucleotide deletion, the loss of a nucleotide
• Nucleotide insertion, the addition of a nucleotide

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If a mutation changed a codon from GGU to GGA
then what would happen? If a mutation changed
a codon from GGA to UGA then what would happen?
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Normal hemoglobin DNA
Mutant hemoglobin DNA
mRNA
mRNA
Normal hemoglobin
Sickle-cell hemoglobin
Figure 10.21
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• Insertions and deletions can
• Change the reading frame of the genetic message
• Lead to disastrous effects

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mRNA and protein from a normal gene
Base substitution
Figure 10.22a
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mRNA and protein from a normal gene
Deleted
Nucleotide deletion
Figure 10.22b
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mRNA and protein from a normal gene
Inserted
Nucleotide insertion
Figure 10.22c
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mRNA and protein from a normal gene
(a) Base substitution
Deleted
(b) Nucleotide deletion
Inserted
(c) Nucleotide insertion
Figure 10.22
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Mutation by Deletion
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The Human Genome Project

• Begun in 1990, the Human Genome Project was a
  massive scientific endeavor
• To determine the nucleotide sequence of all the
  DNA in the human genome and
• To identify the location and sequence of every
  gene
• Aims of the project
• - to identify the estimated 100,000 genes in the
  human DNA.

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• At the completion of the project in 2004
• Over 99 of the genome had been determined to
  99.999 accuracy
• 3.2 billion nucleotide pairs were identified
• About 24,000 genes were found
• About 98 of the human DNA was identified as
  noncoding

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• The Human Genome Project can help map the genes
  for specific diseases such as
• Alzheimers disease
• Parkinsons disease

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Table 12.1
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Benefits of Human Genome Project research

• - improvements in medicine.
• - microbial genome research for fuel and
  environmental cleanup.
• - DNA forensics.
• - improved agriculture and livestock.
• - better understanding of evolution and human
  migration.
• - more accurate risk assessment.

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Making Humulin

• In 1982, the worlds first genetically engineered
  pharmaceutical product was sold.
• Humulin, human insulin
• Was produced by genetically modified bacteria
• Was the first recombinant DNA drug approved by
  the FDA
• Is used today by more than 4 million people with
  diabetes

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• Today, humulin is continuously produced in
  gigantic fermentation vats filled with a liquid
  culture of bacteria.

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If a strand of DNA has the sequence AAGCTC,
transcription will result in a(n) ______. A)
single RNA strand with the sequence TTCGAG B) DNA
double helix with the sequence AAGCTC for one
strand and TTCGAG for the complementary strand C)
single DNA strand with the sequence TTCGAG D)
single RNA strand with the sequence UUCGAG E) RNA
double helix with the sequence UUCGAG for one
strand and AAGCUC for the complimentary strand
29
If a strand of DNA has the sequence AAGCTC,
transcription will result in a(n) ______. A)
single RNA strand with the sequence TTCGAG B) DNA
double helix with the sequence AAGCTC for one
strand and TTCGAG for the complementary strand C)
single DNA strand with the sequence TTCGAG D)
single RNA strand with the sequence UUCGAG E) RNA
double helix with the sequence UUCGAG for one
strand and AAGCUC for the complimentary strand
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Translation converts the information stored in
______ to ______. A) DNA . . . RNA B) RNA . . .
a polypeptide C) protein . . . DNA D) DNA . . . a
polypeptide E) RNA . . . DNA
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Translation converts the information stored in
______ to ______. A) DNA . . . RNA B) RNA . . .
a polypeptide C) protein . . . DNA D) DNA . . . a
polypeptide E) RNA . . . DNA
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Where is translation accomplished? A)
lysosomes B) smooth endoplasmic reticulum C)
peroxisomes D) ribosomes E) nucleoli
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Where is translation accomplished? A)
lysosomes B) smooth endoplasmic reticulum C)
peroxisomes D) ribosomes E) nucleoli
34
A mutation within a gene that will insert a
premature stop codon in mRNA would ______. A)
result in a polypeptide that is one amino acid
shorter than the one produced prior to the
mutation B) result in a shortened polypeptide
chain C) result in a missense mutation D) change
the location at which transcription of the next
gene begins E) have the same effect as deleting a
single nucleotide in the gene
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A mutation within a gene that will insert a
premature stop codon in mRNA would ______. A)
result in a polypeptide that is one amino acid
shorter than the one produced prior to the
mutation B) result in a shortened polypeptide
chain C) result in a missense mutation D) change
the location at which transcription of the next
gene begins E) have the same effect as deleting a
single nucleotide in the gene
36
What is the smallest number of nucleotides that
must be added or subtracted to change the triplet
grouping of the genetic message? A) one B) two C)
three D) four E) five
37
What is the smallest number of nucleotides that
must be added or subtracted to change the triplet
grouping of the genetic message? A) one B) two C)
three D) four E) five
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Examine the genetic code table, shown below. The
codon AGC codes for the amino acid ______.
A) serine B) arginine C) threonine D)
alanine E) glycine
39
Examine the genetic code table, shown below. The
codon AGC codes for the amino acid ______.
A) serine B) arginine C) threonine D)
alanine E) glycine
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A mutation would be most harmful to the cells if
it resulted in ______. A) a single nucleotide
insertion near the start of the coding
sequence B) a single nucleotide deletion near the
end of the coding sequence C) a single nucleotide
in the middle of an intron D) substitution of a
base pair E) deletion of a triplet near the
middle of the gene
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A mutation would be most harmful to the cells if
it resulted in ______. A) a single nucleotide
insertion near the start of the coding
sequence B) a single nucleotide deletion near the
end of the coding sequence C) a single nucleotide
in the middle of an intron D) substitution of a
base pair E) deletion of a triplet near the
middle of the gene
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In a DNA double helix, adenine pairs with ______
and guanine pairs with ______. A) cytosine . . .
thymine B) guanine . . . adenine C) uracil . . .
cytosine D) thymine . . . cytosine E) cytosine .
. . uracil
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In a DNA double helix, adenine pairs with ______
and guanine pairs with ______. A) cytosine . . .
thymine B) guanine . . . adenine C) uracil . . .
cytosine D) thymine . . . cytosine E) cytosine .
. . uracil
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RNA contains the nitrogenous base ______ instead
of ______, which is only found in DNA. A) a
deoxyribose sugar . . . a ribose sugar B)
nucleotides . . . nucleic acids C) uracil . . .
thymine D) cytosine . . . guanine E) adenine . .
. guanine
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RNA contains the nitrogenous base ______ instead
of ______, which is only found in DNA. A) a
deoxyribose sugar . . . a ribose sugar B)
nucleotides . . . nucleic acids C) uracil . . .
thymine D) cytosine . . . guanine E) adenine . .
. guanine
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If one strand of a DNA double helix has the
sequence GTCCAT, what is the sequence of the
other strand? A) ACTTGC B) TGAACG C) CAGGTA D)
CAGGUA E) CUGGTU
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If one strand of a DNA double helix has the
sequence GTCCAT, what is the sequence of the
other strand? A) ACTTGC B) TGAACG C) CAGGTA D)
CAGGUA E) CUGGTU
48
What name is given to the collection of traits
exhibited by an organism? A) holotype B)
genotype C) typology D) phenotype E) morphology
49
What name is given to the collection of traits
exhibited by an organism? A) holotype B)
genotype C) typology D) phenotype E) morphology
50
How many nucleotides make up a codon? A) one B)
two C) three D) four E) five
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How many nucleotides make up a codon? A) one B)
two C) three D) four E) five
52
Transcription is the ______. A) manufacture of a
strand of RNA complementary to a strand of DNA B)
manufacture of two new DNA double helices that
are identical to an old DNA double helix C)
modification of a strand of RNA prior to the
manufacture of a protein D) manufacture of a
protein based on information carried by RNA E)
manufacture of a new strand of DNA complementary
to an old strand of DNA
53
Transcription is the ______. A) manufacture of a
strand of RNA complementary to a strand of DNA B)
manufacture of two new DNA double helices that
are identical to an old DNA double helix C)
modification of a strand of RNA prior to the
manufacture of a protein D) manufacture of a
protein based on information carried by RNA E)
manufacture of a new strand of DNA complementary
to an old strand of DNA