Download Gene Expression and Cell Differentiation

141
1/15-19/16
Gene Expression and Cell
Differentiation
EQ: How does DNA and RNA
control the structure and
function of cells and of entire
organisms?
Starter:
•1/15 What do you know
about genes?
•1/19
142
Gene Expression and Cell
Differentiation
1/15-19/16
Practice/Application/Connection
/ Exit:
Notes
141
1/15-19/16
Gene Expression and Cell
Differentiation
EQ: How does DNA and RNA
control the structure and
function of cells and of entire
organisms?
Starter:
•1/15 What do you know
about genes?
•1/19 What is Epigenetics?
142
Gene Expression and Cell
Differentiation
1/15-19/16
Practice/Application/Connection
/ Exit:
Notes
Graphic organizer
Watch Video and write 5 facts
you learn:
https://www.youtube.com/watch
?v=h_1QLdtF8d0&index=21&list=
PLwL0Myd7Dk1F0iQPGrjehze3e
Dpco1eVz
January15-19 , 2016
AGENDA
B. 6 B and D
1 Starter
2. Notes
3.
Students will recognize
that components that make
up the genetic code are
common to all organisms and
recognize that gene
expression is a regulated
process. while reading and
writing by taking notes.
Table of Contents
Date
Lecture/ Activity/ Lab
Page
12/10 Say it With DNA Activity
123-124
12/14
Mutations
125-126
12/15
Mutations2
127-128
1/5
Mutations and Pedigrees
129-130
1/6
Mutations and Pedigrees
131-132
1/7
Mutations and Poster
133-134
1/8
Mutations Writing
135-136
1/11
Pedigrees
137-138
1/12
Semester Exam Review
139-140
1/15 Gene Expression and Cell Differentiation
141-142
Gene Expression and
Cell Differentiation
CSCOPE
Unit: 08 Lesson: 01
There are hundreds of different types
of cells in your body, and each type
has a unique function. We’re going to
compare some different types of cells
to see how much they have in
common.
For each pair of cells in your body, you are
going to predict what percentage of DNA
is the same in the two types of cells.
Record your prediction in on your
notesheet.
What percentage of the DNA is the
Images Courtesy of Wikimedia Commons
same in your blood cells and nerve cells?
What percentage of the DNA is the
Images Courtesy of Wikimedia Commons
same in your rods (eye) and lung cells?
What percentage of the DNA is the
same in your liver and bone cells?
What percentage of the DNA is the
Images Courtesy of Wikimedia Commons
same in your blood cells and nerve cells?
What percentage of the DNA is the
same in your rods (eye) and lung cells?
What percentage of the DNA is the
Images Courtesy of Wikimedia Commons
same in your liver and bone cells?
How can these cells, that have
very different functions, have the
exact same DNA in the nucleus?
How does the body use the exact
same set of instructions to make
such different structures?
 HOW does DNA specify for
traits in an organism?
 HOW does DNA instruct cells?
http://content.dnalc.org/content/c15/15513/tri
plet_code.mp4
 DNA triplets code for one amino acid.
 Amino acids link together to form polypeptides.
 Genes code for polypeptides that control things such as:
 The expression traits (how we look)
 The function of the cell
 Other genes
 A very small percentage of the human genome actually
codes for proteins.
What Does Gene Expression Mean?
(Graphic courtesy of Marianne Dobrovolny)
http://content.dnalc.org/content/c15/15513/tri
plet_code.mp4
Epigenetics
 What causes cells with the same DNA to
differentiate?
 What is one way to turn genes on and off?
 What causes changes in epigenetics? For
example, why do identical twins continue to
become more different in terms of their
epigenetics as they get older?
Gene Regulation
Gene Regulation:
Modification of Genome (DNA)
 Sections of DNA called transposons can be moved to
different chromosomes.
 Chemical factors can structurally change the DNA,
turning it on or off.
 Chemical processes: DNA methylation & histone
modification
 Epigenome
 Gene regulation at the DNA level happens in
eukaryotes and rarely, if ever, in prokaryotes.
 The term epigenome is derived from the Greek word
epi, which literally means "above" the genome.
 The epigenome consists of chemical compounds that
modify, or mark, the genome in a way that tells it
what to do, where to do it, and when to do it (i.e., turn
genes on and off)
 Different cells have different epigenetic marks.
 The environment causes changes in our epigenetics.
In a fetus, cells with the
exact same DNA are
directed to differentiate by
chemical signals that cause
certain genes to be
switched on or off in.
Gene Regulation
Gene Regulation:
Transcriptional Regulation
 Transcriptional factors (regulatory
proteins) turn transcription on and off or
increase and decrease.
 This mechanism happens in eukaryotes
and prokaryotes.
Prokaryotes:
Transcriptional Regulation
 Operon – functioning unit of DNA containing the following:
 A set of genes (DNA the codes for mRNA)
 Regulatory sections (DNA that controls the expression of
the gene)
Prokaryotes:
Transcriptional Regulation
Prokaryotes:
Transcriptional Regulation
Eukaryote:
Transcriptional Regulation
 Much more complicated and involves:
 Many regulatory proteins (transcription factors)
 Enhancers and TATA Box
Eukaryote:
Transcriptional Regulation
Gene Regulation
 One gene can result in several different proteins through a process
called:
Alternate mRNA Splicing
 IMPORTANT: Not all DNA codes for mRNA that then translates into
proteins!!!
 Some DNA codes for non-coding RNA (ncRNA). This ncRNA plays a
very important role in gene expression.
 Some examples of ncRNA you are familiar with and others you are
not:
 tRNA – helps in translation
 rRNA – helps in translation
 miroRNA – prevents translation from happening
 siRNA – destroys mRNA molecules
 snRNA – helps splice exons together during mRNA processing
Gene Regulation
 These mechanisms prevent the synthesis of
proteins.
 Example:
 Regulatory proteins bind to specific sequences in
the mRNA and prevent ribosomes from
attaching.
 Happens in eukaryotes and prokaryotes
Gene Regulation
 Proteins are chemically modified (ex. folded ) after
they are made.
 These chemical mechanisms can cause the folding
process of proteins to change therefore altering
how that protein will be expressed.
Gene Regulation
This technology helps scientists understand the differences in
different types of cells, despite the fact that they have the exact
same DNA.
DNA microarrays help scientists study
the human genome by…
Information Sources
National Institutes of Health. National Human Genome Research Institute. “Talking
Glossary of Genetic Terms.” Retrieved October 16, 2011, from
http://www.genome.gov/glossary/ http://www.genome.gov/glossary/?id=167
NOVA scienceNOW. “Epigenetics.” Retrieved September 16, 2012 from
http://video.pbs.org/video/1525107473#