Unit 2 Replication
Gene Regulation and Mutations
Q1
- the TYR gene is in gametes, skin cells, muscle cells, bone cells, and neurons
- melanin protects the DNA from UV radiation
- they all have this gene, due to cell division different cells contain the same gene
- how genes are used makes them different
Gene Regulation
- genes are transcribed into mRNA (transcription factors DNA accessibility)
- alternative splicing occurs in the mRNA during processing
- during translation, it can interfere with/destroy mRNA, post-translation modifications in protein
- each point can be regulated differently, transcription can be controlled in a cell, processing also
- proteins can be modified, multi-step process, any step can be controlled in a cell
- signal transduction (cell signaling) is when cells receive and respond to signals from outside
the cell
- receptors start a chain reaction, pathways often end in a transcription factor,
increase/decrease factors after transcription
- outside signals affect gene usage, signals activate receptors and molecules,
increase/decrease functions
Q2
- mature mRNA and protein are involved in gene expression and would be impacted by the
presence of isoginkgetin in eukaryotic cells
- spliceosomes remove introns and fuse exons in processing, from pre mRNA to mature mRNA
- if mRNA is changed, then the protein is as well
Mutations
- mutations are permanent changes in the DNA sequences of organisms
- they happen during DNA replication and are induced by environmental factors
- point mutation is a permanent change that affects a single pair of nucleotides in DNA
- there are many categories of point mutations within genes
- silent (different nucleotide in sequence, results in the same protein)
- missense (substitution/switch of an amino acid, wildly variable result, unpredictable)
- nonsense (switch from amino acid to stop codon, results in a shorter protein, may not function
well)
- frameshift (insertion/removal of a nucleotide, all random now, usually bad for protein function)
Q3
- missense is the substitution of one amino acid for another
- this can result in a wild result
, Q4
- silent is a change in DNA, will not affect the protein, removal on introns make sure of this
Q5
- an impactful mutation would be a nonsense mutation in exon #2 resulting in a stop codon
- nonsense comes before frameshift, but location and type matter
Terminology and Hypotheses
Chromatin
- chromatin is the DNA and protein complex found in a eukaryotic cell
- DNA is packaged into nucleosomes that have histone proteins and cores
- they are unique to eukaryotes, very long molecules, DNA is wrapped around histones, one
group of proteins is a nucleosome
- organizes DNA, gene regulation (form of chromatin), cell division
Q1
- sugars, nucleotides, amino acids, and proteins are biological molecules found in chromatin in
eukaryotic cells
- histones are protein, nucleotides are the building blocks of DNA, deoxyribose is the sugar in
nucleotides, amino acids are the monomers of proteins
Chromosomes
- a chromosome is a single piece of chromatin or a replicated set of chromatic pieces that are
attached to each other at the centromere
- a chromatid is one of the two identical halves of a duplicated chromosome
- as long as the copies are attached, equal parts of DNA and protein
- single vs replicated, centromere in the middle, duplicate to get a chromatid
Q2
- after DNA replication, 23 pairs of chromosomes would turn into 46 chromosomes and 92
chromatids
- somatic cells have 23 chromosomes to start with, 46 total all in pairs, 23 from each parent x 2
- goes through replication, start and end with 46 but copies are present, twice as many
chromatids
Q3
- from most to least inclusive: genome, chromosome, DNA molecule, gene, exon, codon,
nucleotide, 5’C
- 5’C sugar in a nucleotide, both in a DNA molecule, genome is a section of a DNA molecule,
has many genes, codon has three nucleotides, inside exons
Replication
- complementary base pairs (G-C and A-T) provide a replication mechanism for DNA
Gene Regulation and Mutations
Q1
- the TYR gene is in gametes, skin cells, muscle cells, bone cells, and neurons
- melanin protects the DNA from UV radiation
- they all have this gene, due to cell division different cells contain the same gene
- how genes are used makes them different
Gene Regulation
- genes are transcribed into mRNA (transcription factors DNA accessibility)
- alternative splicing occurs in the mRNA during processing
- during translation, it can interfere with/destroy mRNA, post-translation modifications in protein
- each point can be regulated differently, transcription can be controlled in a cell, processing also
- proteins can be modified, multi-step process, any step can be controlled in a cell
- signal transduction (cell signaling) is when cells receive and respond to signals from outside
the cell
- receptors start a chain reaction, pathways often end in a transcription factor,
increase/decrease factors after transcription
- outside signals affect gene usage, signals activate receptors and molecules,
increase/decrease functions
Q2
- mature mRNA and protein are involved in gene expression and would be impacted by the
presence of isoginkgetin in eukaryotic cells
- spliceosomes remove introns and fuse exons in processing, from pre mRNA to mature mRNA
- if mRNA is changed, then the protein is as well
Mutations
- mutations are permanent changes in the DNA sequences of organisms
- they happen during DNA replication and are induced by environmental factors
- point mutation is a permanent change that affects a single pair of nucleotides in DNA
- there are many categories of point mutations within genes
- silent (different nucleotide in sequence, results in the same protein)
- missense (substitution/switch of an amino acid, wildly variable result, unpredictable)
- nonsense (switch from amino acid to stop codon, results in a shorter protein, may not function
well)
- frameshift (insertion/removal of a nucleotide, all random now, usually bad for protein function)
Q3
- missense is the substitution of one amino acid for another
- this can result in a wild result
, Q4
- silent is a change in DNA, will not affect the protein, removal on introns make sure of this
Q5
- an impactful mutation would be a nonsense mutation in exon #2 resulting in a stop codon
- nonsense comes before frameshift, but location and type matter
Terminology and Hypotheses
Chromatin
- chromatin is the DNA and protein complex found in a eukaryotic cell
- DNA is packaged into nucleosomes that have histone proteins and cores
- they are unique to eukaryotes, very long molecules, DNA is wrapped around histones, one
group of proteins is a nucleosome
- organizes DNA, gene regulation (form of chromatin), cell division
Q1
- sugars, nucleotides, amino acids, and proteins are biological molecules found in chromatin in
eukaryotic cells
- histones are protein, nucleotides are the building blocks of DNA, deoxyribose is the sugar in
nucleotides, amino acids are the monomers of proteins
Chromosomes
- a chromosome is a single piece of chromatin or a replicated set of chromatic pieces that are
attached to each other at the centromere
- a chromatid is one of the two identical halves of a duplicated chromosome
- as long as the copies are attached, equal parts of DNA and protein
- single vs replicated, centromere in the middle, duplicate to get a chromatid
Q2
- after DNA replication, 23 pairs of chromosomes would turn into 46 chromosomes and 92
chromatids
- somatic cells have 23 chromosomes to start with, 46 total all in pairs, 23 from each parent x 2
- goes through replication, start and end with 46 but copies are present, twice as many
chromatids
Q3
- from most to least inclusive: genome, chromosome, DNA molecule, gene, exon, codon,
nucleotide, 5’C
- 5’C sugar in a nucleotide, both in a DNA molecule, genome is a section of a DNA molecule,
has many genes, codon has three nucleotides, inside exons
Replication
- complementary base pairs (G-C and A-T) provide a replication mechanism for DNA
