Download Regulation of Eukaryotic Genes

Warm-Up (1/4)
On the piece of white paper from the back, answer
the following question.
Explain how a cell expresses a
gene.
Name
Date
Period
3B.1a: Both DNA regulatory sequences, regulatory genes, and small
regulatory RNAs are involved in gene expression.
3B.1a.1: Regulatory sequences are stretches of DNA that interact with
regulatory proteins to control transcription.
Illustrative example: promoters
3B.1a.2: A regulatory gene is a sequence of DNA encoding a regulatory
protein or RNA.
3B.1c: In eukaryotes, gene expression is complex and control involves
regulatory genes, regulatory elements and transcription factors act in
concert.
3B.1c.1: Transcription factors bind to specific DNA sequences and/or
other regulatory proteins.
3B.1c.2: Some of these transcription factors are activators (increase
expression), while others are repressors (decrease expression).
3B.1c.3: The combination of transcription factors binding to the
regulatory regions at any one time determines how much, if any, of the
gene product will be produced.
4C.2a: Environmental factors influence many traits both directly and
indirectly.
Illustrative examples: Effect of increased UV on melanin production
in animals
Regulation of Eukaryotic Genes
protein
RNA
DNA
How does a
gene know
when to start
and end?
Regulation of Eukaryotic Genes
protein
RNA
DNA
How does a
gene know
when to start
and end?
Regulation of Eukaryotic Genes
protein
RNA
DNA
How does a
gene know
when to start
and end?
Regulation of Eukaryotic Genes
protein
RNA
DNA
How does a
gene know
when to turn
on and off?
Regulation of Eukaryotic Genes
Promoters
say where
and when
transcription
starts.
protein
RNA
DNA
regulatory
sequence
coding
sequence
Regulation of Eukaryotic Genes
Transcription factors
bind onto promoters and
regulate transcription.
transcription factor
DNA
promoter
coding
sequence
Regulation of Eukaryotic Genes
They can turn
transcription on or off.
transcription factor
RNA
DNA
promoter
coding
sequence
Regulation of Eukaryotic Genes
They can turn
transcription on or off.
transcription factor
DNA
promoter
coding
sequence
Regulation of Eukaryotic Genes
Activators turn
transcription on.
activator
RNA
DNA
promoter
coding
sequence
Regulation of Eukaryotic Genes
Repressors turn
transcription off.
repressor
DNA
promoter
coding
sequence
Regulation of Eukaryotic Genes
The sum total of activators
and repressors determines
gene expression.
repressor
activator
Should I stay or should I go?
DNA
promoter
coding
sequence
Regulation of Eukaryotic Genes
Regulatory
genes encode
transcription
factors.
Transcription
factor protein
RNA
DNA
regulatory
gene
Critical Thinking Question #1
Discuss this question with your partner and write or
represent it. I will call on three people to share their
partners’ answers.
The gene ATP4A encodes a protein called Gastric
Hydrogen Potassium ATPase, which is responsible for
releasing acid from the parietal cells lining the inside of the
stomach to the inside of the stomach. The genomes (total
DNA) of all somatic cells in a person’s body are identical,
because they all originated from a single zygote (fertilized
egg) through the process of mitosis. Represent (draw,
illustrate, make a diagram) showing how parietal cells are
different from neurons in the brain in the context of acid
secretion.
Critical Thinking Question #2
Discuss this question with your partner and write or
represent it. I will call on three people to share their
partners’ answers.
Explain why it is essential to regulate
the expression of topoisomerase and
helicase in a cell as it proceeds through
the cell cycle and mitosis.
3B.1a: Both DNA regulatory sequences, regulatory genes, and small
regulatory RNAs are involved in gene expression.
3B.1a.1: Regulatory sequences are stretches of DNA that interact with
regulatory proteins to control transcription.
Illustrative example: promoters
3B.1a.2: A regulatory gene is a sequence of DNA encoding a regulatory
protein or RNA.
3B.1c: In eukaryotes, gene expression is complex and control involves
regulatory genes, regulatory elements and transcription factors act in
concert.
3B.1c.1: Transcription factors bind to specific DNA sequences and/or
other regulatory proteins.
3B.1c.2: Some of these transcription factors are activators (increase
expression), while others are repressors (decrease expression).
3B.1c.3: The combination of transcription factors binding to the
regulatory regions at any one time determines how much, if any, of the
gene product will be produced.
4C.2a: Environmental factors influence many traits both directly and
indirectly.
Illustrative examples: Effect of increased UV on melanin production
in animals
Illustrative Example: Melanin Production
transcription
factor activated
Probably British.
UV damage
melanin gene
Illustrative Example: Melanin Production
melanin
Probably British.
UV damage
RNA
melanin gene
Illustrative Example: Melanin Production
Protects
against more
UV damage
melanin
The damage is done, you idiot!
RNA
melanin gene
Closure
On the piece of white paper from the
back, answer the following question:
Describe how two humans
each with identical alleles of
the lactase gene can have
different levels of lactose
intolerance.
Name
Date
Period
Scale
1 – 10