Download Section 1 Control of Gene Expression

Chapter 11
Gene Expression
Table of Contents
Section 1 Control of Gene Expression
Section 2 Gene Expression in Development and
Cell
Division
Chapter 11
Section 1 Control of Gene Expression
Objectives
• Explain why cells regulate gene expression.
• Discuss the role of operons in prokaryotic gene expression.
• Determine how repressor proteins and inducers affect transcription in
prokaryotes.
• Describe the structure of a eukaryotic gene.
• Compare the two ways gene expression is controlled in eukaryotes.
Chapter 11
Section 1 Control of Gene Expression
Role of Gene Expression
• Gene expression is the activation of a gene
that results in transcription and the
production of mRNA.
• Only a fraction of any cell’s genes are
expressed at any one time.
Chapter 11
Section 1 Control of Gene Expression
Gene Expression in Prokaryotes
• An operon is a series of genes that code for
specific products and the regulatory elements
that control these genes. In prokaryotes, the
structural genes, the promoter, and the
operator collectively form an operon.
Chapter 11
Section 1 Control of Gene Expression
Operon
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Visual Concept
Chapter 11
Section 1 Control of Gene Expression
Gene Expression in Prokaryotes,
continued
• A promoter is the
segment of DNA that is
recognized by the enzyme RNA polymerase,
which then initiates transcription.
• An operator is the segment of DNA that acts
as a “switch” by controlling the access of RNA
polymerase to the promoter.
Chapter 11
Section 1 Control of Gene Expression
Gene Expression in Prokaryotes,
• Operon “Turnedcontinued
Off”
– Repressor proteins are coded for by regulator
genes and these proteins inhibit genes from being
expressed.
– A repressor protein attaches to the operator,
physically blocking the advancement of RNA
polymerase.
Chapter 11
Section 1 Control of Gene Expression
Repression of Transcription in the lac Operon
Click below to watch the Visual Concept.
Visual Concept
Chapter 11
Section 1 Control of Gene Expression
Gene Expression in Prokaryotes,
• Operon “Turnedcontinued
On”
– An inducer is a molecule that initiates gene
expression. In E. coli, lactose serves as an inducer.
– An inducer binds to the repressor protein and the
repressor protein detaches from the operator.
RNA polymerase can then advance to the
structural genes.
Chapter 11
Section 1 Control of Gene Expression
Activation of Transcription in the lac Operon
Click below to watch the Visual Concept.
Visual Concept
Chapter 11
Section 1 Control of Gene Expression
Mechanism of lac Operon
How are these skin cells different?
Do they have the same DNA?
Gene Expression in Eukaryotes
• Structure of a Eukaryotic Gene
– Eukaryotes do not have operons.
– The genomes of eukaryotes are larger and more
complex than those of prokaryotes.
– Eukaryotic genes are organized into noncoding
sections, called introns, and coding sections,
called exons.
• Control After Transcription
– In eukaryotes, gene expression can be controlled
after transcription—through the removal of
introns from pre-mRNA.
Control at the Onset of Transcription
In eukaryotes, gene expression can be
controlled at the onset of transcription—
through the action of regulatory proteins
known as transcription factors.
CANCER- (Malignant Neoplasms)
ANIMATED INTRODUCTION TO CANCER
BIOLOGY (FULL DOCUMENTARY) 12:07
Chapter 11
Section 2 Gene Expression in
Development and Cell Division
Objectives
• Summarize the role of gene expression in an organism’s development.
• Describe the influence of homeotic genes in eukaryotic development.
• State the role of the homeobox in eukaryotic development.
• Summarize the effects of mutations in causing cancer.
• Compare the characteristics of cancer cells with those
normal cells.
of
Chapter 11
Section 2 Gene Expression in
Development and Cell Division
Gene Expression in Development
• The development of cells with specialized functions is
called cell differentiation.
• The development of form in an organism is called
morphogenesis.
• Both cell differentiation and morphogenesis are governed
by gene expression.
• The development of cells with specialized functions is
called cell differentiation.
• The development of form in an organism is called
morphogenesis.
• Both cell differentiation and morphogenesis are
governed by gene expression.
• Homeotic Genes
– Homeotic genes are regulatory genes that determine
where anatomical structures will be placed during
development.
• Homeobox Sequences
– Within each homeotic gene, a specific DNA sequence known as
the homeobox regulates patterns of development.
– The homeoboxes of many eukaryotic organisms appear to be
very similar.
• Tracking Changes in Gene Expression
– In the 1990s, researchers developed a tool for tracking
gene expression called a DNA chip.
Gene Expression, Cell Division, and Cancer
• Mutations of proto-oncogenes, which regulate cell
growth, or tumor-suppressor genes, which prevent cell
division from occurring too often, may lead to cancer.
• Cancer is the uncontrolled growth of abnormal cells.
Types of Cancer
Carcinomas- Skin and tissues that line the organs
Sarcomas- bone and muscle tissue
Lymphomas- lymphatic system
Leukemia- blood
Acute Lymphoblastic Leukemia (ALL)
Acute Myeloid Leukemia (AML)
Adolescents, Cancer in
Adrenocortical Carcinoma
Childhood
AIDS-Related Cancers
Kaposi Sarcoma
Lymphoma
Anal Cancer
Appendix Cancer
Astrocytomas, Childhood
Atypical Teratoid/Rhabdoid Tumor,
Childhood, Central Nervous System
B
Basal Cell Carcinoma - see Skin Cancer
(Nonmelanoma)
Childhood
Bile Duct Cancer, Extrahepatic
Bladder Cancer
Childhood
Bone Cancer
Ewing Sarcoma Family of Tumors
Osteosarcoma and Malignant Fibrous
Histiocytoma
Brain Stem Glioma, Childhood
Brain Tumor
Astrocytomas, Childhood
Brain and Spinal Cord Tumors
Treatment Overview, Childhood
Brain Stem Glioma, Childhood
Central Nervous System Atypical
Teratoid/Rhabdoid Tumor, Childhood
Central Nervous System Embryonal
Tumors, Childhood
Central Nervous System Germ Cell
Tumors, Childhood
Craniopharyngioma, Childhood
Ependymoma, Childhood
Breast Cancer
Childhood
Male
Pregnancy, Breast Cancer and
Bronchial Tumors, Childhood
Burkitt Lymphoma - see Non-Hodgkin
Lymphoma
C
Carcinoid Tumor
Childhood
Gastrointestinal
Carcinoma of Unknown Primary
Childhood
Cardiac (Heart) Tumors, Childhood
Central Nervous System
Atypical Teratoid/Rhabdoid Tumor,
Childhood
Embryonal Tumors, Childhood
Germ Cell Tumor, Childhood
Lymphoma, Primary
Cervical Cancer
Childhood
Childhood Cancers
Chordoma, Childhood
Chronic Lymphocytic Leukemia (CLL)
Chronic Myelogenous Leukemia (CML)
Chronic Myeloproliferative Neoplasms
Colon Cancer
Colorectal Cancer
Childhood
Craniopharyngioma, Childhood
Cutaneous T-Cell Lymphoma - see
Mycosis Fungoides and Sézary
Syndrome
D
Duct, Bile, Extrahepatic
Ductal Carcinoma In Situ (DCIS)
E
Embryonal Tumors, Central Nervous
System, Childhood
Endometrial Cancer
Ependymoma, Childhood
Esophageal Cancer
Childhood
Esthesioneuroblastoma, Childhood
Ewing Sarcoma
Extracranial Germ Cell Tumor,
Childhood
Extragonadal Germ Cell Tumor
Extrahepatic Bile Duct Cancer
Eye Cancer
Intraocular Melanoma
Retinoblastoma
F
Fallopian Tube Cancer
Fibrous Histiocytoma of Bone,
Malignant, and Osteosarcoma
G
Gallbladder Cancer
Gastric (Stomach) Cancer
Childhood
Gastrointestinal Carcinoid Tumor
Gastrointestinal Stromal Tumors (GIST)
Childhood
Germ Cell Tumor
Central Nervous System, Childhood
Extracranial, Childhood
Extragonadal
Ovarian
Testicular
Gestational Trophoblastic Disease
Glioma - see Brain Tumor
Childhood Brain Stem
H
Hairy Cell Leukemia
Head and Neck Cancer
Childhood
Heart Cancer, Childhood
Hepatocellular (Liver) Cancer
Histiocytosis, Langerhans Cell
Hodgkin Lymphoma
Hypopharyngeal Cancer
I
Intraocular Melanoma
Islet Cell Tumors, Pancreatic
Neuroendocrine Tumors
K
Kaposi Sarcoma
Kidney
Renal Cell
Wilms Tumor and Other Childhood
Kidney Tumors
L
Langerhans Cell Histiocytosis
Laryngeal Cancer
Childhood
Leukemia
Acute Lymphoblastic (ALL)
Acute Myeloid (AML)
Chronic Lymphocytic (CLL)
Chronic Myelogenous (CML)
Hairy Cell
Lip and Oral Cavity Cancer
Liver Cancer (Primary)
Childhood
Lung Cancer
Childhood
Non-Small Cell
Small Cell
Lymphoma
AIDS-Related
Burkitt - see Non-Hodgkin Lymphoma
Cutaneous T-Cell - see Mycosis
Fungoides and Sézary Syndrome
Hodgkin
Non-Hodgkin
Primary Central Nervous System (CNS)
M
Macroglobulinemia, Waldenström
Male Breast Cancer
Malignant Fibrous Histiocytoma of Bone
and Osteosarcoma
Melanoma
Childhood
Intraocular (Eye)
Merkel Cell Carcinoma
Mesothelioma, Malignant
Childhood
Metastatic Squamous Neck Cancer with
Occult Primary
Midline Tract Carcinoma Involving NUT
Gene
Mouth Cancer
Multiple Endocrine Neoplasia
Syndromes, Childhood
Multiple Myeloma/Plasma Cell
Neoplasm
Mycosis Fungoides
Myelodysplastic Syndromes
Myelodysplastic/Myeloproliferative
Neoplasms
Myelogenous Leukemia, Chronic (CML)
Myeloid Leukemia, Acute (AML)
Myeloma, Multiple
Myeloproliferative Neoplasms, Chronic
N
Nasal Cavity and Paranasal Sinus Cancer
Nasopharyngeal Cancer
Childhood
Neuroblastoma
Non-Hodgkin Lymphoma
Non-Small Cell Lung Cancer
O
Oral Cancer
Childhood
Oral Cavity Cancer, Lip and
Oropharyngeal Cancer
Osteosarcoma and Malignant Fibrous
Histiocytoma of Bone
Ovarian Cancer
Childhood
Epithelial
Germ Cell Tumor
Low Malignant Potential Tumor
P
Pancreatic Cancer
Childhood
Pancreatic Neuroendocrine Tumors
(Islet Cell Tumors)
Papillomatosis, Childhood
Paraganglioma
Childhood
Paranasal Sinus and Nasal Cavity Cancer
Parathyroid Cancer
Penile Cancer
Pharyngeal Cancer
Pheochromocytoma
Childhood
Pituitary Tumor
Plasma Cell Neoplasm/Multiple
Myeloma
Pleuropulmonary Blastoma, Childhood
Pregnancy and Breast Cancer
Primary Central Nervous System (CNS)
Lymphoma
Primary Peritoneal Cancer
Prostate Cancer
R
Rectal Cancer
Renal Cell (Kidney) Cancer
Renal Pelvis and Ureter, Transitional Cell
Cancer
Retinoblastoma
Rhabdomyosarcoma, Childhood
S
Salivary Gland Cancer
Childhood
Sarcoma
Ewing
Kaposi
Osteosarcoma (Bone Cancer)
Rhabdomyosarcoma
Soft Tissue
Uterine
Sézary Syndrome
Skin Cancer
Childhood
Melanoma
Merkel Cell Carcinoma
Nonmelanoma
Small Cell Lung Cancer
Small Intestine Cancer
Soft Tissue Sarcoma
Squamous Cell Carcinoma - see Skin
Cancer (Nonmelanoma)
Childhood
Squamous Neck Cancer with Occult
Primary, Metastatic
Stomach (Gastric) Cancer
Childhood
T
T-Cell Lymphoma, Cutaneous - see
Mycosis Fungoides and Sézary
Syndrome
Testicular Cancer
Childhood
Throat Cancer
Thymoma and Thymic Carcinoma
Childhood
Thyroid Cancer
Childhood
Transitional Cell Cancer of the Renal
Pelvis and Ureter
U
Unknown Primary, Carcinoma of
Childhood
Unusual Cancers of Childhood
Ureter and Renal Pelvis, Transitional Cell
Cancer
Urethral Cancer
Uterine Cancer, Endometrial
Uterine Sarcoma
V
Vaginal Cancer
Childhood
Vulvar Cancer
W
Waldenström Macroglobulinemia
Wilms Tumor
Women's Cancers
Y
Young Adults, Cancer in
Effect of Mutation on Gene
Expression
• Gene Expression in Cancer
– Unlike normal cells, cancer cells continue to divide
indefinitely, even if they become densely packed.
– Cancer cells will also continue dividing even if they are
no longer attached to other cells.
• Causes of Cancer
– A carcinogen is any substance that can induce or
promote cancer.
– Most carcinogens are mutagens, substances that cause
mutations.
Chapter 11
Standardized Test Prep
Multiple Choice
1. Which of the following codes for a repressor
protein?
A. enhancer
B. promoter
C. regulator gene
D. structural gene
Chapter 11
Standardized Test Prep
Multiple Choice, continued
1. Which of the following codes for a repressor
protein?
A. enhancer
B. promoter
C. regulator gene
D. structural gene
Chapter 11
Standardized Test Prep
Multiple Choice, continued
2. Which component of an operon controls the
advancement of RNA polymerase?
F. exon
G. operator
H. promoter
J. structural gene
Chapter 11
Standardized Test Prep
Multiple Choice, continued
2. Which component of an operon controls the
advancement of RNA polymerase?
F. exon
G. operator
H. promoter
J. structural gene
Chapter 11
Standardized Test Prep
Multiple Choice, continued
3. Pre-mRNA contains which of the following?
A. exons only
B. introns only
C. both introns and exons
D. neither introns nor exons
Chapter 11
Standardized Test Prep
Multiple Choice, continued
3. Pre-mRNA contains which of the following?
A. exons only
B. introns only
C. both introns and exons
D. neither introns nor exons
Chapter 11
Standardized Test Prep
Multiple Choice, continued
The graph below shows the number
of cigarettes smoked per capita per
year between 1920 and 2000 and
the annual incidence of lung cancer
among women. Use the graph to
answer the question that follows.
4. What was the relationship between
number of cigarettes smoked and
incidence of lung cancer?
F. There was no relationship between
cigarette smoking and lung cancer.
G. As the number of cigarettes smoked
decreased, the incidence of lung cancer
increased.
H. As the number of cigarettes smoked
increased, the incidence of lung cancer
increased.
J. As the number of cigarettes smoked
increased, the incidence of lung cancer
decreased.
Chapter 11
Standardized Test Prep
Multiple Choice, continued
The graph below shows the number
of cigarettes smoked per capita per
year between 1920 and 2000 and
the annual incidence of lung cancer
among women. Use the graph to
answer the question that follows.
4. What was the relationship between
number of cigarettes smoked and
incidence of lung cancer?
F. There was no relationship between
cigarette smoking and lung cancer.
G. As the number of cigarettes smoked
decreased, the incidence of lung cancer
increased.
H. As the number of cigarettes smoked
increased, the incidence of lung cancer
increased.
J. As the number of cigarettes smoked
increased, the incidence of lung cancer
decreased.
Chapter 11
Standardized Test Prep
Multiple Choice, continued
5. skin : carcinoma :: blood-forming tissue :
A. sarcoma
B. leukemia
C. lymphoma
D. carcinogen
Chapter 11
Standardized Test Prep
Multiple Choice, continued
5. skin : carcinoma :: blood-forming tissue :
A. sarcoma
B. leukemia
C. lymphoma
D. carcinogen
Chapter 11
Standardized Test Prep
Multiple Choice, continued
The diagram below shows
how mutations in certain
genes can lead to cancer. Use
the diagram to answer the
questions that follow.
6. What does X represent?
F. mutagens
G. carcinogens
H. proto-oncogenes
J. tumor-suppressor genes
Chapter 11
Standardized Test Prep
Multiple Choice, continued
The diagram below shows
how mutations in certain
genes can lead to cancer. Use
the diagram to answer the
questions that follow.
6. What does X represent?
F. mutagens
G. carcinogens
H. proto-oncogenes
J. tumor-suppressor genes
Chapter 11
Standardized Test Prep
Multiple Choice, continued
The diagram below shows
how mutations in certain
genes can lead to cancer. Use
the diagram to answer the
questions that follow.
7. What does Y represent?
A. mutagens
B. carcinogens
C. proto-oncogenes
D. tumor-suppressor genes
Chapter 11
Standardized Test Prep
Multiple Choice, continued
The diagram below shows
how mutations in certain
genes can lead to cancer. Use
the diagram to answer the
questions that follow.
7. What does Y represent?
A. mutagens
B. carcinogens
C. proto-oncogenes
D. tumor-suppressor genes