BRAINSCAPE1
BCMB 406A Lab 3 Exam with complete
solutions latest version
Histone - CORRECT ANSWER-Highly conserved and highly alkaline eukaryotic
proteins that bind DNA to form a nucleosome which is the building block of chromatin
Purpose of Lab 3: - CORRECT ANSWER-To examine how two post-translational
modifications (trimethylation of lysine 4 and 36) of histone H3 can vary depending on
the position of the nucleosome within an active gene in yeast.
Histone variant deposition - CORRECT ANSWER-When different forms of histones are
placed at specific positions in a gene to serve a different function than the original
histone. The purpose is similar to that of post-translational modifications of the histones
Chromatin remodelling complexes - CORRECT ANSWER-Complexes capable of
restructuring chromatin (compacting it tighter and down regulating expression or
opening it up and up regulating expression) by interfering with nucleosome formation
and/or structure
3 ways chromatin can affect gene regulation - CORRECT ANSWER-1. Post-
translational modifications (PTMs) on chromatin
2. Chromatin remodeling
3. Incorporation of histone variants
Incorporation of histone variants on chromatin - CORRECT ANSWER-(H2A.z, H1.1,
H2A.x) can be incorporated to attract different transcriptional machinery
ex. Incorporating a histone variant into the nucleosomes of the promoter region opens
the area up to recruit RNA polymerase II
Haploid - CORRECT ANSWER-A cell or organism containing one copy of each
chromosome
BRAINSCAPE1
, BRAINSCAPE1
Diploid - CORRECT ANSWER-A cell or organism containing two copies of each
chromosome
Spheroplast - CORRECT ANSWER-A cell that has had the cell wall removed. These
cells are fragile and easily lysed by changes in osmolarity.
Ubiquitination - CORRECT ANSWER-A post-translational modification whereby a
protein is tagged with ubiquitin, a small regulatory protein. Once tagged, these proteins
are often targeted for degradation by the proteosome.
Sumoylation - CORRECT ANSWER-A post-translational modification whereby a protein
is tagged with SUMO (small ubiquitin-like modifier). Unlike ubiquitination, summation
often increases the stability and lifespan of a protein. Can only target lysine amino
acids.
Telomere - CORRECT ANSWER-The terminal end of a chromosome. This non-
transcribed DNA is usually a simple repeating sequence with a single-stranded region
that may fold into a hairpin. It protects the chromosome from degradation.
What do post-translational modifications of histone proteins do? - CORRECT ANSWER-
Control the functional properties of chromatin in eukaryotes
What does the effect of a PTM depend on? - CORRECT ANSWER-The position on the
histone and the location in the gene.
Chromatin Structure - Condensing steps - CORRECT ANSWER-1. Nucleosome core
particle
2. Chromatin: nucleosomes joined by linker DNA
3. Further condensing of chromatin forms chromosome.
What allows for the dynamics of chromatin? - CORRECT ANSWER-N-terminal tails of
histones protrude from the nucleosome and can be modified by PTMs
Epigenetics - CORRECT ANSWER-The study of heritable changes in genome function
that occur without a change in DNA sequence (2nd layer of information on chromatin).
Response to environmental stresses.
What 2 changes can influence epigenetics? - CORRECT ANSWER-1. Changes in
histones
2. Changes in DNA
Why is yeast considered a model organism? - CORRECT ANSWER-- Single-celled
eukaryote that is easily cultured and has simple genetics.
- Haploid genome
- Histones are highly conserved in eukaryotes, so it can be used to study chromatin
structure and function.
BRAINSCAPE1
BCMB 406A Lab 3 Exam with complete
solutions latest version
Histone - CORRECT ANSWER-Highly conserved and highly alkaline eukaryotic
proteins that bind DNA to form a nucleosome which is the building block of chromatin
Purpose of Lab 3: - CORRECT ANSWER-To examine how two post-translational
modifications (trimethylation of lysine 4 and 36) of histone H3 can vary depending on
the position of the nucleosome within an active gene in yeast.
Histone variant deposition - CORRECT ANSWER-When different forms of histones are
placed at specific positions in a gene to serve a different function than the original
histone. The purpose is similar to that of post-translational modifications of the histones
Chromatin remodelling complexes - CORRECT ANSWER-Complexes capable of
restructuring chromatin (compacting it tighter and down regulating expression or
opening it up and up regulating expression) by interfering with nucleosome formation
and/or structure
3 ways chromatin can affect gene regulation - CORRECT ANSWER-1. Post-
translational modifications (PTMs) on chromatin
2. Chromatin remodeling
3. Incorporation of histone variants
Incorporation of histone variants on chromatin - CORRECT ANSWER-(H2A.z, H1.1,
H2A.x) can be incorporated to attract different transcriptional machinery
ex. Incorporating a histone variant into the nucleosomes of the promoter region opens
the area up to recruit RNA polymerase II
Haploid - CORRECT ANSWER-A cell or organism containing one copy of each
chromosome
BRAINSCAPE1
, BRAINSCAPE1
Diploid - CORRECT ANSWER-A cell or organism containing two copies of each
chromosome
Spheroplast - CORRECT ANSWER-A cell that has had the cell wall removed. These
cells are fragile and easily lysed by changes in osmolarity.
Ubiquitination - CORRECT ANSWER-A post-translational modification whereby a
protein is tagged with ubiquitin, a small regulatory protein. Once tagged, these proteins
are often targeted for degradation by the proteosome.
Sumoylation - CORRECT ANSWER-A post-translational modification whereby a protein
is tagged with SUMO (small ubiquitin-like modifier). Unlike ubiquitination, summation
often increases the stability and lifespan of a protein. Can only target lysine amino
acids.
Telomere - CORRECT ANSWER-The terminal end of a chromosome. This non-
transcribed DNA is usually a simple repeating sequence with a single-stranded region
that may fold into a hairpin. It protects the chromosome from degradation.
What do post-translational modifications of histone proteins do? - CORRECT ANSWER-
Control the functional properties of chromatin in eukaryotes
What does the effect of a PTM depend on? - CORRECT ANSWER-The position on the
histone and the location in the gene.
Chromatin Structure - Condensing steps - CORRECT ANSWER-1. Nucleosome core
particle
2. Chromatin: nucleosomes joined by linker DNA
3. Further condensing of chromatin forms chromosome.
What allows for the dynamics of chromatin? - CORRECT ANSWER-N-terminal tails of
histones protrude from the nucleosome and can be modified by PTMs
Epigenetics - CORRECT ANSWER-The study of heritable changes in genome function
that occur without a change in DNA sequence (2nd layer of information on chromatin).
Response to environmental stresses.
What 2 changes can influence epigenetics? - CORRECT ANSWER-1. Changes in
histones
2. Changes in DNA
Why is yeast considered a model organism? - CORRECT ANSWER-- Single-celled
eukaryote that is easily cultured and has simple genetics.
- Haploid genome
- Histones are highly conserved in eukaryotes, so it can be used to study chromatin
structure and function.
BRAINSCAPE1
