PUBH 6011 final exam 2023 actual questions and answers
100% verified
Two types of cell death
apoptosis: programmed cell death
necrosis: cell damage and death
Virus vs bacteria
virus: only active within host cells which they need to reproduce
bacteria: single-celled organisms that produce own energy and can reproduce on their
own
DNA base pairing
A-T
G-C
DNA strands held together by...
hydrogen bonds
DNA to protein
DNA encodes the sequence of proteins carried in DNA
Gene
DNA coding (for protein, for trait)
Protein functions
structural support, storage, transport, cellular communications, movement, and defense
against foreign substances
Protein sequence
determines how protein will fold
Protein structure
determines function
Enzyme
enhances rate of chemical reaction in body; catalysts, so not used up in reaction
Process of DNA to protein
DNA > transcription > RNA > transcription > protein
Genome
all of an organism's genetic material
Epigenetics
the study of influences on gene expression that occur without a DNA change
determines which genes are expressed
Epigenetics results in
heritable changes in the phenotype without changes to DNA sequence/structure
(genotype)
Can epigenetic modifications be transferred from generation to generation?
YES
Three mechanisms of epigenetics
1. DNA methylation
2. histone modification
3. micro-RNAs
,DNA methylation
adding a methyl group to DNA to switch off the gene
possible connection between DNA methylation of 5 genes and PM 2.5
Histone
protein molecule around which DNA is tightly coiled in chromatin
Histone modification
changes in the structure of histones that make it more or less likely that a segment of
DNA will be transcribed
acetyl group allows for transcription
Epigenetic factor that binds to histone tail
acetyl group; allows for transcription
Micro-RNAs
bind to complementary RNA to prevent translation
Mutation
heritable changes in genetic information
genotype change
Microlesions
base pair substitution
2 types of microlesions
change in DNA sequence
change in codon (if coding region)
Change in codon - 3 outcomes
no effect = degenerate code
missense mutation = change amino acid, sometimes function
nonsense mutation = premature termination or splice change
Types of genetic mutations in lecture
microlesions
frameshift mutations
macro lesions
Types of genetic mutations
1. Deletion
2. Duplication
3. Inversion
4. Insertion
5. Translocation
frameshift mutation
mutation that shifts the "reading" frame of the genetic message by inserting or deleting
a nucleotide
consequences: altered protein, often non-functional
macrolesions
chromosomal aberrations
change in chromosomal structure
change in chromosome number
Cause of chromosomal aberration
effects on mitotic machinery, not DNA
Macrolesion mutation: change in chromosome structure
, deletion, duplication, inversion, translocation -- usually cell death
Macrolesion mutation: change in chromosome number
aneuploidy: increase number of one+ chromosomes
polyploidy: increase in whole set
Aneuploidy
A chromosomal aberration in which one or more chromosomes are present in extra
copies or are deficient in number.
Polyploidy
condition in which an organism has extra sets of chromosomes
polymorphism
the individual differences of form among the members of a species
can change function of proteins
Health effects of mutation
germ cells/ova: point mutations may be lethal
somatic cells: source of variability (polymorphism); concern = carcinogenesis
How does cancer arise?
DNA mutations in cells
uncontrolled proliferation
Proto-oncogene mutation
leads to altered forms of normal cellular genes
tumor supressor gene
mutation
can promote apoptosis
can act as "brake" to regulate proliferation of normal cells
Genotoxic compounds
directly alter DNA
point mutations
chromosomal aberrations
point mutation
gene mutation in which a single base pair in DNA has been changed
nongenotoxic compound
do not directly alter DNA but can increase cancer risk
increase chance of replication errors and increase number of cells at risk
cancer types with highest mortality in US
women: lung, breast, colon
men: lung, prostate, colon
innate immunity
- immunity that is present before exposure and effective from birth
- responds to a broad range of pathogens
physical barriers help prevent entry
0-12 hours after infection -- immediate
adaptive immunity
- the ability to recognize and remember specific antigens and mount an attack on them
detects molecules (usually proteins) on surface of cells and learns to ignore self
proteins
100% verified
Two types of cell death
apoptosis: programmed cell death
necrosis: cell damage and death
Virus vs bacteria
virus: only active within host cells which they need to reproduce
bacteria: single-celled organisms that produce own energy and can reproduce on their
own
DNA base pairing
A-T
G-C
DNA strands held together by...
hydrogen bonds
DNA to protein
DNA encodes the sequence of proteins carried in DNA
Gene
DNA coding (for protein, for trait)
Protein functions
structural support, storage, transport, cellular communications, movement, and defense
against foreign substances
Protein sequence
determines how protein will fold
Protein structure
determines function
Enzyme
enhances rate of chemical reaction in body; catalysts, so not used up in reaction
Process of DNA to protein
DNA > transcription > RNA > transcription > protein
Genome
all of an organism's genetic material
Epigenetics
the study of influences on gene expression that occur without a DNA change
determines which genes are expressed
Epigenetics results in
heritable changes in the phenotype without changes to DNA sequence/structure
(genotype)
Can epigenetic modifications be transferred from generation to generation?
YES
Three mechanisms of epigenetics
1. DNA methylation
2. histone modification
3. micro-RNAs
,DNA methylation
adding a methyl group to DNA to switch off the gene
possible connection between DNA methylation of 5 genes and PM 2.5
Histone
protein molecule around which DNA is tightly coiled in chromatin
Histone modification
changes in the structure of histones that make it more or less likely that a segment of
DNA will be transcribed
acetyl group allows for transcription
Epigenetic factor that binds to histone tail
acetyl group; allows for transcription
Micro-RNAs
bind to complementary RNA to prevent translation
Mutation
heritable changes in genetic information
genotype change
Microlesions
base pair substitution
2 types of microlesions
change in DNA sequence
change in codon (if coding region)
Change in codon - 3 outcomes
no effect = degenerate code
missense mutation = change amino acid, sometimes function
nonsense mutation = premature termination or splice change
Types of genetic mutations in lecture
microlesions
frameshift mutations
macro lesions
Types of genetic mutations
1. Deletion
2. Duplication
3. Inversion
4. Insertion
5. Translocation
frameshift mutation
mutation that shifts the "reading" frame of the genetic message by inserting or deleting
a nucleotide
consequences: altered protein, often non-functional
macrolesions
chromosomal aberrations
change in chromosomal structure
change in chromosome number
Cause of chromosomal aberration
effects on mitotic machinery, not DNA
Macrolesion mutation: change in chromosome structure
, deletion, duplication, inversion, translocation -- usually cell death
Macrolesion mutation: change in chromosome number
aneuploidy: increase number of one+ chromosomes
polyploidy: increase in whole set
Aneuploidy
A chromosomal aberration in which one or more chromosomes are present in extra
copies or are deficient in number.
Polyploidy
condition in which an organism has extra sets of chromosomes
polymorphism
the individual differences of form among the members of a species
can change function of proteins
Health effects of mutation
germ cells/ova: point mutations may be lethal
somatic cells: source of variability (polymorphism); concern = carcinogenesis
How does cancer arise?
DNA mutations in cells
uncontrolled proliferation
Proto-oncogene mutation
leads to altered forms of normal cellular genes
tumor supressor gene
mutation
can promote apoptosis
can act as "brake" to regulate proliferation of normal cells
Genotoxic compounds
directly alter DNA
point mutations
chromosomal aberrations
point mutation
gene mutation in which a single base pair in DNA has been changed
nongenotoxic compound
do not directly alter DNA but can increase cancer risk
increase chance of replication errors and increase number of cells at risk
cancer types with highest mortality in US
women: lung, breast, colon
men: lung, prostate, colon
innate immunity
- immunity that is present before exposure and effective from birth
- responds to a broad range of pathogens
physical barriers help prevent entry
0-12 hours after infection -- immediate
adaptive immunity
- the ability to recognize and remember specific antigens and mount an attack on them
detects molecules (usually proteins) on surface of cells and learns to ignore self
proteins
