Project Lead The Way
Medical Intervention
Exam 1 Review
Disclaimer
This review is an overview. There is no
possible way to revisit every single item we
have covered thus far. This should be used
as 1 tool in your preparation for the exam.
Major Focus
Key Terms – Crossword Puzzles 1.1 – 1.3
Key Concepts – Each Activity/Project
Essential Questions – Each Unit
Conclusion Questions – Each Activity/Project
Knowledge and Skills – Each Unit
Quizzes
Exam 1 Review
Unit 1.1.1 through Unit 1.3.3
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Activity 1.1.1 Medical Interventions Inventory
Activity 1.1.2 Investigating an Outbreak
Activity 1.1.3 Using DNA to Identify Pathogens
Problem 1.1.4 What's the Concentration?
Activity 1.1.5 ELISA
Activity 1.1.6 Final Diagnosis
 Activity 1.2.1 Antibiotic Therapy
 Project 1.2.3 Attack of the Superbugs
 Activity 1.2.4 When Antibiotics Fail
 Activity 1.3.1 Good Vibrations
 Activity 1.3.2 Can You Hear Me Now?
 Activity 1.3.3 Cochlear Implant Debate
Unit 1 - The Mystery Infection
Activity 1.1.2 Investigating an Outbreak
What do you think of when you hear the term
infection?
What is an infection?
Infection is the invasion of a host organism's
body tissues by disease-causing agents, their
multiplication, and the reaction of host tissues to
these organisms and the toxins they produce.
Unit 1 - The Mystery Infection
Activity 1.1.2 Investigating an Outbreak
Are there different types of infections?
Infectious agents:
Viruses
Bacteria
Prions (misfolded protein)
Parasites (nematodes, arthropods)
Fungi
Unit 1 - The Mystery Infection
Activity 1.1.2 Investigating an Outbreak
Ebola
• disease of humans and other primates
• caused by the ebola virus
Late Stages:
• Dec. liver & kidney function
• Internal & external bleeding
Unit 1 - The Mystery Infection
Activity 1.1.2 Investigating an Outbreak
Strep throat
• Streptococcus bacteria
• gram-positive bacterium
Symptoms:
Fever
sore throat
enlarged lymph nodes
Cause of 37% of sore throats among children
Cause of 10-15% of sore throats among adults
Unit 1 - The Mystery Infection
Activity 1.1.2 Investigating an Outbreak
Necator americanus (Hookworm)
• Nematode that lives in the small intestine of hosts
• Parasitic infection
• 740 million people
Symptoms:
abdominal pain, diarrhea,
cramps, weight loss,
anorexia and iron deficiency
Unit 1 - The Mystery Infection
Activity 1.1.2 Investigating an Outbreak
Athlete's foot
• most commonly caused by the fungi Trichophyton
rubrum or T. mentagrophytes
• Fungal infection
Symptoms:
Scaling
Flaking
Itching
Inflammation
blistering
Activity 1.1.2 Summary
Investigating an Outbreak
A number of patients showed up at infirmary
Sue, Jill, Anthony, Wanda, Maggie, Maria, Arnie
Objective: To determine cause of illness of each patient
Analyzed medical history, symptoms, cause of illness,
possible routes of transmission
four major illnesses – bacterial meningitis, infectious
mononucleosis, Strep throat, and influenza
Activity 1.1.3 Using DNA to Identify Pathogens
DNA
What does DNA stand for?
What is DNA?
What does DNA do?
Who discovered DNA?
Where is DNA found?
DNA
deoxyribonucleic acid (DNA)
DNA
What is DNA?
What does DNA do?
DNA Comprised of 4 Nucleotides
There are only
4 DNA nucleotides
• adenine
• thymine
• cytosine
• guanine
Chromatin
DNA → RNA → Protein
DNA carries genetic information
that codes for proteins
DNA is transcribed into RNA (DNA → RNA )
RNA is translated into protein (RNA → Protein)
Proteins are used for
Enzymes (catalysis), structures, antibodies,
hormones, etc
DNA
Who discovered DNA?
History of DNA
In 1953 James Watson and Francis Crick
proposed the double helix for DNA
Awarded Nobel Prize in 1962
History of DNA
Information from other sources including X-ray
diffraction studies from Rosalind Franklin
Rosalind Franklin died so she wasn’t eligible for
the Nobel Prize.
DNA
Where is DNA found?
DNA
DNA
Is DNA found anywhere else?
DNA
Mitochondrial DNA (mtDNA)
• In multicellular organisms, mitochondrial DNA is double stranded and
codes for 37 genes and containing approximately 16,600 base pairs
• Each mitochondrion is estimated to contain 2-10 mtDNA copies
• mtDNA is derived from the circular genomes of the bacteria that were
engulfed by the early ancestors of today's eukaryotic cells
 Endosymbiotic Theory
• mtDNA is inherited maternally inherited
Of the 37 genes:
13 are for proteins (enzymes) involved in oxidative phosphorylation
22 are for transfer RNA (tRNA) and 2 are for ribosomal RNA (rRNA) which
help assemble amino acids into functioning proteins
Mitochondrial DNA (mtDNA)
Nuclear DNA
Human Genome
• 3 billion base pairs
• Organized into 23 paired chromosomes
• Approx 20-25,000 genes
Beta Globin Gene
Hemoglobin
• Gene found on chromosome 11
• Beta globin Protein
• Primary component of RBCs
– 4 sub-units
– 2 of Alpha-globin
– 2 of Beta-globin
– Each carries 1 oxygen
molecule
Beta Globin
People with sickle cell have abnormal hemoglobin
How can computers and genetic
information be paired to help prevent,
diagnose or treat disease?
Activity 1.1.3 Summary
Using DNA to Identify Pathogens
You are introduced to the field of bioinformatics as you
learned how to analyze DNA to identify pathogens
Questions:
How can scientists identify specific bacteria when they
are amplifying and studying the same region of DNA in
each species?
How can DNA sequencing be used to identify genetic risk
for certain diseases and disorders?
Activity 1.1.3 Summary
BLAST results show that the Neisseria meningitidis
bacterium is found in Sue’s system.
Neisseria meningitidis bacterium is the leading cause of?
Bacterial Meningitis
Meningitis is an infection found where in the body?
The fluid of a person's spinal cord and the fluid that
surrounds the brain
Problem 1.1.4 What's the Concentration?
Problem 1.1.4 Summary
What is the Concentration?
You were presented with a 1L container of solution with an
unknown amount of solute and asked to devise a method
to determine the concentration of the solute.
What was the purpose of this exercise (activity)?
What is a spectrophotometer?
How can a spectrophotometer be used to investigate a
disease?
How is this relevant to health/medicine?
Absorbance
Absorbance
Why is a red ball red?
Any object will appear red when it absorbs all
wavelengths of visible light except for red
So how does knowing the frequency of light that is
absorbed help you determine the concentration?
Absorbance
Beer-Lambert Law (aka Beer’s Law)
A=ebc
A is absorbance (no units)
e is the molar absorbtivity (units = L/mol/cm)
b is the path length of the sample (units = centimeters)
c is the concentration of the compound in solution (units = mol/L)
** molar absorbtivity is the same as molar extinction coefficient
Absorbance
Unknown
?
Unknown
Set of Standards
1
2
3
4
5
Set of Standards
6
What does serial dilutions have to do
with an ELISA?
Activity 1.1.5 ELISA
Activity 1.1.5 Summary
ELISA
ELISA assays were used to detect the presence of the
Neisseria meningitidis antigen.
What is an ELISA?
What are the types of ELISA assays?
How does an ELISA work?
Activity 1.1.5 Summary
Activity 1.1.5 Summary
You were asked to diagram or model how the ELISA test
can be used to detect Neisseria meningitidis.
Activity 1.1.5 Summary
An ELISA assay can provide qualitative or quantitative
results.
What does this mean??
Antibodies
What is an antibody?
Antibodies
An antigen-binding immunoglobulin, produced by
B cells, that functions as the effector in an
immune response
Antibodies
Important regions of an antibody
Antibodies
5 known antibody isotypes
IgA
IgD
IgE
IgG
IgM
GAMED
Activity 1.1.6 Final Diagnosis
Bioinformatics data and lab testing will eventually reveal the following results:
Patient Diagnosis
Sue - Bacterial meningitis
Jill - Bacterial meningitis
Anthony - Influenza
Wanda - Infectious mononucleosis
Maggie - Strep throat
Maria - Bacterial meningitis
Arnie - Influenza
Marco - Bacterial meningitis
Alvin - Infectious mononucleosis
Alvin does not submit to molecular testing; however, his association with
Wanda and his symptoms will lead students to a diagnosis of infectious
mononucleosis.
Activity 1.1.6 Final Diagnosis
Outbreak Assessment:
Who is patient zero on campus?
Sue
How did this disease spread on campus?
• One possible hypothesis: Sue brought the bacteria back from her visit to the
other college
• Jill lives with Sue and plays on the same sports team, they share many cups,
utensils and water bottles.
• Either Jill or Sue passed the infection to Maria, who is always in their room.
• Sue had lab with Marco. They may have shared a soda during the break and had
other contact leading to transmission of the bacterium
Activity 1.1.6 Final Diagnosis
Outbreak Assessment:
What is the appropriate treatment?
Use antibiotics to treat those infected
What other medical interventions should be used?
• Provide the bacterial meningitis vaccine to those who are unaffected
• Test other students at the college that Sue visited
Unit 1.1 Essential Questions
1) What is a medical intervention?
2) What are the main categories of interventions that function to maintain human health?
3) How do scientists gather evidence during the potential outbreak of an infectious disease?
4) What is bioinformatics?
5) How can DNA sequences be used to identify disease pathogens?
6) What is an antibody?
7) How do antibodies identify and inactivate antigens?
8) How can the ELISA assay be used to detect disease?
9) Why is it important for doctors to know the concentration of disease antigen present in a
patient’s system?
10) What steps do scientists take to diagnose, treat, and prevent future spread of a disease
outbreak?
Unit 1.2 - Antibiotics
Unit 1.2 - Antibiotic Treatment
Antibiotic Resistance
The mass use of antibiotics has resulted in new strains of bacteria that are
resistant to antibiotics
Over the last decade, almost every type of bacteria known to cause disease
has become stronger and less responsive to antibiotic treatment
Increasing number of antibiotic resistant bacteria: Tuberculosis, gonorrhea,
malaria, skin infections, pneumonia, & ear infections
Antibiotic resistance has been called one of the world’s most pressing
public health problems and is one of the Centers for Disease Control’s top
concerns.
Unit 1.2 - Antibiotic Treatment
Mechanism of Action
Specific antibiotics are effective at preventing the growth of certain
strains of bacteria
The effectiveness of antibiotics is dependent on the mechanism of
action of the drug and the structure of the bacteria
Unit 1.2 - Antibiotic Treatment
Activity 1.2.3 – Attack of Superbugs
Introduction
In this activity, you learned about the structure of a bacterial cell in order
to understand how different classes of antibiotics work.
You also made a superbug from 2 separate plates containing bacteria
Unit 1.2 - Antibiotic Treatment
What is a bacterium?
What are the types of bacteria?
How do antibiotics kill bacteria?
Unit 1.2 - Antibiotic Treatment
What is a bacterium?
• Bacteria are a large group of unicellular, prokaryote, microorganisms
• Typically a few micrometers in length
• A wide range of shapes (ranging from spheres to rods and spirals)
• 40 million bacterial cells in a gram of soil
• A million bacterial cells in a milliliter of fresh water
• Approximately five nonillion (5×1030) bacteria on Earth
Unit 1.2 - Antibiotic Treatment
A Typical Bacterium
Unit 1.2 - Antibiotic Treatment
A Typical Bacterium
Do Not Memorize This
Particular Image. Although
bacteria have all these
features they can often look
slightly different from image
to image.
Unit 1.2 - Antibiotic Treatment
Bacterial DNA
Chromosomal: bacteria possess a single chromosome composed of
double‐stranded DNA in a closed loop. The DNA is located in the nucleoid of
the cell and is not associated with protein. Transfer of chromosomal DNA is
accomplished through replication then division to daughter cells.
Plasmid: A small circular double-stranded DNA molecule that carries
accessory genes separate from those of the bacterial chromosome. They
carry a small number of genes. Easily transferred between bacteria in
cellular contact.
Unit 1.2 - Antibiotic Treatment
Bacterial Gene Transfer
Three primary types of gene transfer between bacterial cells
1) Bacterial conjugation is the transfer of genetic material (plasmid)
between bacterial cells by direct cell-to-cell contact or by a bridge-like
connection between two cells
2) Transduction is the process by which DNA is transferred from one
bacterium to another by a virus. It also refers to the process whereby
foreign DNA is introduced into another cell via a viral vector.
3) Transformation is the genetic alteration of a cell resulting from the direct
uptake and incorporation of exogenous genetic material (exogenous
DNA) from its surroundings and taken up through the cell membrane(s).
Unit 1.2 - Antibiotic Treatment
Gram Staining
Gram-negative bacteria
• Thin cell wall consisting of a few layers of peptidoglycan surrounded by a second
lipid membrane containing lipopolysaccharides and lipoproteins
• Do not retain crystal violet dye in the Gram staining protocol due to their
lipopolysaccharide outer layer
• In a Gram stain test, a counterstain (commonly safranin) is added after the crystal
violet, coloring all Gram-negative bacteria with a red or pink color.
Gram-positive bacteria
• Do not have an outer membrane BUT they have a thickened peptidoglycan layer
• Will retain the crystal violet dye when washed in a decolorizing solution
Unit 1.2 - Antibiotic Treatment
Gram Staining
The higher lipid content of the gram-negative bacteria cell walls allows the alcohol
destain to wash the purple colored stain out of the cells.
Gram positive bacteria will retain the purple color because the alcohol is not able
to destain the purple color from the cells.
Gram negative bacteria stain reddish-pink
Gram positive bacteria stain purple
“Positively Purple”
Unit 1.2 Antibiotic Treatment
Gram Staining
Gram Negative
Gram Positive
Unit 1.2 Antibiotic Treatment
Gram Staining
Unit 1.2 - Antibiotic Treatment
Mechanism of Action
Specific antibiotics are effective at preventing the growth of certain
strains of bacteria
The effectiveness of antibiotics is dependent on the mechanism of
action of the drug and the structure of the bacteria
Unit 1.2 - Antibiotic Treatment
How do antibiotics work?
A number of bacterial processes, including the synthesis of bacterial cell walls,
proteins, metabolic pathways, and the integrity of the cytoplasmic membrane, are
the targets of most antibacterial drugs.
4 Main Classes of Antibiotics:
1) β-Lactam Antibiotics
2) Tetracyclines
3) Fluoroquinolones
4) Sulfonamides
Unit 1.2 - Antibiotic Treatment
β-Lactam Antibiotics
“Blocks cell wall synthesis”
Irreversibly inhibit enzymes involved in the final steps of cell wall synthesis. These
drugs vary in their spectrum of activity; some are more active against Gram positive
bacteria; whereas, others are more active against Gram negative bacteria.
Tetracyclines
“Blocks protein synthesis”
Reversibly bind to the 30S ribosomal subunit, blocking the attachment of tRNA to
the ribosome and preventing the continuation of protein synthesis. They are
effective against certain Gram positive and Gram negative bacteria.
Unit 1.2 - Antibiotic Treatment
Fluoroquinolones
“Disrupts bacterial DNA organization”
Inhibit one or more of a group of enzymes called topoisomerases, which maintain
the supercoiling of the chromosomal DNA within the bacterial cells. The inhibition
of these enzymes prevents essential cell processes. The fluoroquinolones are active
against a wide variety of bacteria, including both Gram positive and Gram negative.
Sulfonamides
“Disrupts metabolic pathways”
Inhibit the growth of many Gram positive and Gram negative bacteria. They are
structurally similar to paraminobenzoic acid (PABA), a substrate in the pathway for
folic acid biosynthesis. Because of this similarity, the enzyme that normally binds
with PABA preferentially binds with the sulfonamide drugs, resulting in its
competitive inhibition. Human cells are not affected by these drugs because they
lack this enzyme.
Unit 1.2 Antibiotic Treatment
Unit 1.2.4.A – When Antibiotics Fail
Exposure to an antibiotic naturally selects for the survival of the
organisms with the genes for resistance. In this way, a gene for
antibiotic resistance may readily spread through an ecosystem of
bacteria. Antibiotic-resistance plasmids frequently contain genes
conferring resistance to several different antibiotics.
What does it mean by select?
Unit 1.2 Antibiotic Treatment
Antibiotic Resistance
It may take the form of a spontaneous or induced genetic mutation, or the
acquisition of resistance genes from other bacterial species by horizontal
gene transfer via conjugation, transduction, or transformation.
Many antibiotic resistance genes reside on transmissible plasmids,
facilitating their transfer via conjugation.
Unit 1.2 - Antibiotic Treatment
Understandings
• Antibiotics disrupt the pathways that bacteria use to survive.
• Bacterial cells use multiple pathways to gain resistance to antibiotics.
• Overuse and misuse of antibiotics promotes the selection of resistant bacteria.
Knowledge and Skills
It is expected that you will:
• Label the structures of a bacterial cell.
• Explain the method of action for different classes of antibiotics.
• Describe the pathways through which bacterial cells transfer genes.
• Explain the importance of taking antibiotics as prescribed.
• Use proper laboratory techniques to “mate” a streptomycin resistant strain of E.
coli with an ampicillin resistant strain of E. coli.
• Simulate the effects of antibiotics on a bacterial population during an infection.
• Simulate the effect of a missed dose of antibiotics on a bacterial population
during an infection.
Unit 1.2 - Antibiotic Treatment
Unit 1.2 - Essential Questions
1) How do antibiotics work to fight bacterial infections?
2) What methods do bacteria use to share antibiotic resistant genes?
3) What actions are humans taking that are contributing to bacteria
becoming resistant to commonly used antibiotics?
Lesson 1.3 - Hearing Loss
Lesson 1.3
The Aftermath: Hearing Loss
As we continue to follow Sue Smith we learn that she is still dealing with
the aftermath of her bacterial meningitis infection.
The antibiotics eliminated the infection and Sue made a full recovery
Although Sue has not noticed any symptoms of hearing loss, she has
scheduled an appointment to have her hearing evaluated due to the high
incidence of hearing loss in patients who have recovered from meningitis.
In this lesson you will:
• Investigate the physics of sound
• Learn how hearing works
• Conduct a variety of hearing assessments
Lesson 1.3
The Aftermath: Hearing Loss
Lesson Overview
You will be assigned a patient with a specific type of hearing loss.
Using the assigned patient case study you will:
• Explore how damage to the outer, middle, and/or inner ear results in
hearing loss
• Learn how to interpret audiograms and match up their patient case study
with the corresponding audiogram
• Use what you have learned to make a recommendation as to what
intervention is the most appropriate for the patient case study
• Investigate both sides of the cochlear implant debate
Lesson 1.3
The Aftermath: Hearing Loss
Hearing loss affects millions of people in the United States
Hearing loss can drastically impact a person’s ability to communicate
A significant amount of time and money has been invested into research
to develop interventions to treat hearing loss
Although the degree of hearing loss varies from individual to individual,
there are only three types of hearing loss:
1) Sensorineural hearing loss
2) Conductive hearing loss
3) Mixed hearing loss
Lesson 1.3
The Aftermath: Hearing Loss
Understandings
Problems with one or more structures within the ear cause various types
of hearing loss.
There are a variety of interventions available to help people with hearing
loss.
Lesson 1.3
The Aftermath: Hearing Loss
Knowledge and Skills
It is expected that students will:
• Identify the structures of the ear and describe their function in hearing.
• Describe the pathway of sound vibrations from the time a sound is
generated to the time the brain registers the sound.
• Recognize that there are bioethical concerns and considerations related
to the use of cochlear implant technology.
• Demonstrate sensorineural versus conductive hearing loss on a model of
the ear.
• Perform several simple tests, such as Rinne Test and the Pure Tone Test,
to evaluate hearing.
• Interpret audiograms to identify different types of hearing loss.
• Recommend the most appropriate type of intervention for a patient with
hearing loss, given the patient’s audiogram.
Lesson 1.3
The Aftermath: Hearing Loss
1.3.1 – Good Vibrations
1.3.2 – Hear Me Now
1.3.3 – Cochlear Implant Debate
Lesson 1.3
The Aftermath: Hearing Loss
1.3.1 – Good Vibrations
• Labeled structures of ear
• The Physics of Sound
• Patient case study
Lesson 1.3
The Aftermath: Hearing Loss
1.3.2 – Hear Me Now
• Rinne Test
• Speech-in-Noise Test
• Audiogram Analysis
Lesson 1.3
The Aftermath: Hearing Loss
1.3.3 – Cochlear Implant Debate
• Controversy
• Effectiveness
Lesson 1.3
The Aftermath: Hearing Loss
Essential Questions
1) How do frequency and amplitude affect how humans interpret sound?
2) What causes different types of hearing loss?
3) How is hearing loss diagnosed?
4) What interventions are available for patients with hearing loss?
5) What are the bioethical concerns related to the use of cochlear implant
technology?