N5315 Advanced
Pathophysiology Genetics
Core Concepts and Objectives with Advanced Organizers
Genetics
1. Analyze the pathological processes which alter the structure and role of the DNA and
RNA molecules.
a. Describe the structure and function of the DNA molecule and its clinical significance.
● DNA (double strand) Genes are composed of DNA and most important is the 4 types of
nitrogenous bases (adenine, cytosine, guanine, thymine). Adenine pairs with thymine,
and guanine pairs with cytosine. A T and GC
● Each DNA consist of one deoxyribose molecule, one phosphate group, one base called a
nucleotide.
● DNA serves as the blueprint of proteins in the body, genes ultimately influence all aspects
of body structure and function
b. Evaluate the process of DNA replication and describe how it is altered by mutations.
● DNA replication consist of the breaking of the weak hydrogen bonds between the bases,
leaving a single stand with each base unpaired.
● Complementary base pairing is the pairing of adenine with thymine and guanine with
cytosine. This is the key to accurate replication. This means the unpaired base will attach
to a nucleotide only if has the complementary base.
● When replication is complete a new identical strand will be formed. This new strand is
called a template by which is built from the complementary molecule.
● Proteins are involved in the replication by one protein unwinds the double helix, one
holds the strands apart, and other have different functions. The most important protein
is the enzyme called DNA polymerase; the enzyme travels along the DNA strand,
adding the correct nucleotide, the DNA polymerase performs a proofreading procedure.
● The DNA polymerase checks that the base is complementary to the template base. If it
not the correct nucleotide it will replace it with the correct one.
● Mutation is an inherited alteration of genetic material.
○ Base pair substitution- one base pair is replaced by another (missense mutation)
because the “sense” of the codon produced after transcription of the mutate gene
is altered which results in chase in amino acid sequence b/c of the redundancy of
the genetic code, it may have no consequence.
○ Profound consequence- when an amino acid sequence is altered by a base pair
substitution
○ Frameshift mutation- insertion/deletion of one or more basic pairs to the DNA
molecule-change the entire “reading frame” of the DNA sequence b/c codons
consist of groups of three base pairs.
c. Describe the structure and function of the RNA molecule and its clinical significance.
1
, N5315 Advanced
Pathophysiology Genetics
Core Concepts and Objectives with Advanced Organizers
• RNA (a single strand)- a type of nucleic acid chemically similar to DNA. Bases of RNA :
(adenine, cytosine, guanine, uracil)- A U and GC
• RNA transmits genetic information from DNA to proteins produced by the cell. RNA
carries out the instructions encoded in DNA. RNA is similar to DNA except thymine is
replaced by uracil. RNA occurs in a single strand.
d. Explain the processes of translation and transcription.
Transcription (occurs in nucleus)
• Process by which RNA is synthesized from a
DNA template result formation for messenger RNA
(mRNA) from the base sequence specified by the
DNA molecule
• Transcription of a gene begins when enzyme
RNA polymerase binds to a promoter site of DNA
• Promoter site- a sequence of DNA the specifies
the beginnings of a gene
• Transcription factors (protein) bind to
Transcription factor binding sites (DNA sequences)
near genes to
regulate the timing of transcription as well as the
specific tissues in which genes are actively
transcribed ie. Clotting factor VIII primarily in
hepatocytes
• Transcription factors can either activate or repress
expression of genes and sometimes up-regulated by
the binding of nearby DNA sequenced called
enhancers
• RNA polymerase pulls portion of DNA strands apart
from one another-allowing unattached DNA bases to
be exposed
• One of the DNA strands then provides template
for sequence of mRNA nucleotides
• Sequence of bases in mRNA is complementary to that of template strand with the exception
of the presence of uracil instead of thymine
• Transcription continues until a DNA called termination sequence is reached RNA
polymerase detaches from DNA and transcribed mRNA is freed to move out of nucleus into
cytoplasm
2
Pathophysiology Genetics
Core Concepts and Objectives with Advanced Organizers
Genetics
1. Analyze the pathological processes which alter the structure and role of the DNA and
RNA molecules.
a. Describe the structure and function of the DNA molecule and its clinical significance.
● DNA (double strand) Genes are composed of DNA and most important is the 4 types of
nitrogenous bases (adenine, cytosine, guanine, thymine). Adenine pairs with thymine,
and guanine pairs with cytosine. A T and GC
● Each DNA consist of one deoxyribose molecule, one phosphate group, one base called a
nucleotide.
● DNA serves as the blueprint of proteins in the body, genes ultimately influence all aspects
of body structure and function
b. Evaluate the process of DNA replication and describe how it is altered by mutations.
● DNA replication consist of the breaking of the weak hydrogen bonds between the bases,
leaving a single stand with each base unpaired.
● Complementary base pairing is the pairing of adenine with thymine and guanine with
cytosine. This is the key to accurate replication. This means the unpaired base will attach
to a nucleotide only if has the complementary base.
● When replication is complete a new identical strand will be formed. This new strand is
called a template by which is built from the complementary molecule.
● Proteins are involved in the replication by one protein unwinds the double helix, one
holds the strands apart, and other have different functions. The most important protein
is the enzyme called DNA polymerase; the enzyme travels along the DNA strand,
adding the correct nucleotide, the DNA polymerase performs a proofreading procedure.
● The DNA polymerase checks that the base is complementary to the template base. If it
not the correct nucleotide it will replace it with the correct one.
● Mutation is an inherited alteration of genetic material.
○ Base pair substitution- one base pair is replaced by another (missense mutation)
because the “sense” of the codon produced after transcription of the mutate gene
is altered which results in chase in amino acid sequence b/c of the redundancy of
the genetic code, it may have no consequence.
○ Profound consequence- when an amino acid sequence is altered by a base pair
substitution
○ Frameshift mutation- insertion/deletion of one or more basic pairs to the DNA
molecule-change the entire “reading frame” of the DNA sequence b/c codons
consist of groups of three base pairs.
c. Describe the structure and function of the RNA molecule and its clinical significance.
1
, N5315 Advanced
Pathophysiology Genetics
Core Concepts and Objectives with Advanced Organizers
• RNA (a single strand)- a type of nucleic acid chemically similar to DNA. Bases of RNA :
(adenine, cytosine, guanine, uracil)- A U and GC
• RNA transmits genetic information from DNA to proteins produced by the cell. RNA
carries out the instructions encoded in DNA. RNA is similar to DNA except thymine is
replaced by uracil. RNA occurs in a single strand.
d. Explain the processes of translation and transcription.
Transcription (occurs in nucleus)
• Process by which RNA is synthesized from a
DNA template result formation for messenger RNA
(mRNA) from the base sequence specified by the
DNA molecule
• Transcription of a gene begins when enzyme
RNA polymerase binds to a promoter site of DNA
• Promoter site- a sequence of DNA the specifies
the beginnings of a gene
• Transcription factors (protein) bind to
Transcription factor binding sites (DNA sequences)
near genes to
regulate the timing of transcription as well as the
specific tissues in which genes are actively
transcribed ie. Clotting factor VIII primarily in
hepatocytes
• Transcription factors can either activate or repress
expression of genes and sometimes up-regulated by
the binding of nearby DNA sequenced called
enhancers
• RNA polymerase pulls portion of DNA strands apart
from one another-allowing unattached DNA bases to
be exposed
• One of the DNA strands then provides template
for sequence of mRNA nucleotides
• Sequence of bases in mRNA is complementary to that of template strand with the exception
of the presence of uracil instead of thymine
• Transcription continues until a DNA called termination sequence is reached RNA
polymerase detaches from DNA and transcribed mRNA is freed to move out of nucleus into
cytoplasm
2
