1. Chapter 10 Objectives Describe how the lac operon is turned on or off.
Section 2 Gene Regulation and Structure
Chapter 10
Objectives
Describe how the lac operon is turned on or off.
Summarize the role of transcription factors in regulating eukaryotic gene expression.
Describe how eukaryotic genes are organized.
Evaluate three ways that gene alterations can alter genetic material.

2. New Vocabulary Lac operon Repressor protein Transcription factor
Intron
Exon
Point mutation
Frameshift mutation
Transposon \

3. Regulation of Gene Expression
Section 2 Gene Regulation and Structure
Chapter 10
Regulation of Gene Expression
Both prokaryotic and eukaryotic cells are able to _______________ which genes are expressed and which are not, depending on the cell’s _________.
If specific proteins are not needed all of the time, it would be a ___________ of energy for the cell to continually make them
Review…
What did we call the sequence of DNA that signals for the start of transcription?
regulate
needs
waste
promoter site

4. Section 2 Gene Regulation and Structure
Chapter 10
In prokaryotes, a _______________ protein may bind to DNA in order to ________ or ___________ RNA polymerase from binding to the promoter site and beginning transcription
repressor
block
prevent

5. Chapter 10 recognizing consuming breaking operon sugar
Section 2 Gene Regulation and Structure
Chapter 10
The three genes on the prokaryotic DNA strand below are involved with ______________, ________________, and ______________ down lactose
The entire set of bacterial DNA that controls the consumption of lactose is called the lac ________________
Recall that lactose is a disaccharide ___________ found in milk
recognizing
consuming
breaking
operon
sugar

6. When you consume dairy products, the lactose eventually makes its way into your _______________, where prokaryotic bacteria must break it down
When you are _____ consuming dairy, the repressor protein binds to DNA and the series of gene are _________
intestines
not
“off”

7. When lactose is present, it binds to the repressor protein, changing its ____________, which causes it to _________ off of the DNA strand
Now it is no longer blocking ______ polymerase from binding with the ______________ site, so transcription may occur and the genes are _______
shape
fall
RNA
promoter
“on”

8. Section 2 Gene Regulation and Structure
Chapter 10
The regulation of gene expression in eukaryotes is more _____________ than in prokaryotes for several reasons…
Eukaryotes have many more ________ than prokaryotes
Typical prokaryote = __________ genes
Humans = ____________ genes
Similar genes in eukaryotes are not ________ together like in prokaryotes…they are often found on different _______________
complex
genes
2000
30,000
grouped
chromosomes

9. Additionally, a nuclear _____________ separates transcription and translation in eukaryotes, so there are many more opportunities for gene regulation
Regulation may occur _______________, ______________, or ___________ transcription,…but most often occurs at the _____________
envelope
before
during
after
onset

10. Chapter 10 transcription
Section 2 Gene Regulation and Structure
Chapter 10
transcription
Special eukaryotic proteins, called ____________ factors and ____________ help to arrange RNA polymerase on the promoter site properly
activators

11. Intervening DNA in Eukaryotic Genes
Section 2 Gene Regulation and Structure
Chapter 10
Intervening DNA in Eukaryotic Genes
In eukaryotes, many genes are interrupted by ____________ —long segments of nucleotides that have no __________ information.
These portions are said to _______________ with protein synthesis
The portions of a gene that are translated or expressed into proteins are called __________
After a eukaryotic gene is transcribed, the introns in the resulting mRNA are _______ out by proteins called ______________
introns
coding
“intervene”
exons
cut
spliceosomes

12. Section 2 Gene Regulation and Structure
Chapter 10
Spliceosomes also __________ or “stitch” the remaining __________ together
The new mRNA containing only __________, exits the nucleus
splice
exons
exons

13. This arrangement of exons and introns in genes may have an evolutionary advantage…
Sometimes the exons get ___________ between different gene segments, allowing several different _____________ of a gene to exist
For example, our cells have _____ different hemoglobin genes that are all capable of producing the protein hemoglobin
shuffled
variations 12

14. Section 2 Gene Regulation and Structure
Chapter 10
Mutations
Errors in DNA ______________ or ____________ may cause mutations that code for ____________ amino acids
Mutations may…
have ____ effect on an organism
be ____________
Be ____________
The two main types of mutations are gene _______________ and gene _________________
replication
division
incorrect no
harmful
beneficial
rearrangements
alterations

15. Chapter 10 Gene Rearrangements
Section 2 Gene Regulation and Structure
Chapter 10
Gene Rearrangements
Gene rearrangements are mutations that move an __________ gene to a new location on a chromosome
This may affect a gene’s expression because it is exposed to different _____________ proteins
It could be comparable to moving to France but not being able to __________ French
entire
regulatory
speak

16. divide transposons jump
Sometimes gene rearrangements occur when DNA does not ___________ properly during cell division
Other gene rearrangements are the result of ______________, special genes that can actually ________ and change positions along a DNA strand
divide
transposons
jump

17. Before a transposition, a gene sequence may read A B C, but after it may read ___________
Transposons are responsible for the streaked ________ pattern seen on Indian corn… their positions prevent _________ proteins from being produced, causing portions of the cob to lack color
A C B
color
pigment

18. Scientists think that transposons may play a significant role in _________________ and may help researchers pinpoint the causes of ___________
They were actually first discovered by Barbara _____________ in the 1950s, but her work was not recognized or honored for more than 20 years
evolution
cancer
McClintock

19. Chapter 10 Gene Alterations
Section 2 Gene Regulation and Structure
Chapter 10
Gene Alterations
Gene alterations are mutations that change a portion of a __________ gene
Two types of gene alterations are…
_______________ mutations
single
point
frameshift

20. Chapter 10 Point Mutations changes GGA Point mutations may
Section 2 Gene Regulation and Structure
Chapter 10
Point Mutations
In a point mutation, a single nucleotide _____________
So, if a codon reads GGG, after a point mutation it may read _______
Since several codons code for the same amino acid, sometimes point mutations do _____ alter the protein being made…but sometimes they do
changes
GGA
Point mutations may
also be called
________________
not
substitutions

21. Chapter 10 Frameshift Mutations
Section 2 Gene Regulation and Structure
Chapter 10
Frameshift Mutations
In a frameshift mutation, nucleotides are __________
or _________________
Because the genetic code is read in ___________, insertions and deletions often upset the triplet grouping
inserted
deleted
triplets

22. Section 2 Gene Regulation and Structure
Chapter 10
These mutations may cause a gene’s nucleotides to __________, causing the _________ three nucleotide sequences to be read
Sometimes scientists compare proteins to sentences…
Imagine deleting the letter C from the sentence…
THE CAT ATE ____________________
The remaining triplet sequences would be altered and rendered ________________
shift
wrong
THE ATA TE
useless

23. Objective 1 Describe how the lac operon is turned on or off.
Off = repressor protein binds to DNA at the operator
and blocks RNA polymerase from binding
On = lactose binds to repressor protein, changing
the shape of it and making it fall off the DNA
strand allowing RNA Polymerase to get past

24. Objective 2
Summarize the role of transcription factors in regulating eukaryotic gene expression.
They help to arrange RNA polymerase correctly
on eukaryotic DNA

25. Objective 3 Describe how eukaryotic genes are organized.
The genes are located on DNA which coils
up into chromosomes…similar genes are often
scattered on different chromosomes

26. Objective 4
Evaluate three ways that gene alterations can alter genetic material.
Point mutations
Frameshift mutations – insertion or deletions