Applied Medical Science Exam 3 Flashcards
What does the transesophogeal ridge develop into?
The Tracheoesophageal Ridge Forms a Septum to
Separate the Trachea and Esophagus
What does the respiratory diverticulum develop into?
The respiratory diverticulum lengthens to form the trachea and
then divides to form two lung buds
What do the long buds develop into?
These buds divide into three branches on the right and two on the left, reflecting the number of lobes of the respective lungs on those sides
Types of alveolar cells
Type 1
Type 2
16% of alveolar cells are present at birth; remainder develop for
10 years
Type 1 Alveolar cells
Gas Exchange
Type 2 Alveolar cells
(6.5-7 months) = secrete surfactant =
reduces surface tension in the alveoli so they can remain open
during breathing. If not for surfactant, alveoli would collapse.
Pleura of lungs
Visceral pleura covers the lungs directly
Parietal pleura forms the lung cavity
Both are formed from the lateral plate of the mesoderm
3 domains of life
Bacteria
archaea
Eukarya
Domian bacteria
Usually single‐celled. Majority have cell wall with peptidoglycan. Most lack a membrane‐bound nucleus. Ubiquitous and some live in extreme environments. Cyanobacteria produce significant amounts of oxygen.
Domain Eukarya
Protists—generally larger than Bacteria and Archaea.
• Algae—photosynthetic.
• Protozoa—may be motile, “hunters, grazers”.
• Slime molds—two life cycle stages.
• Water molds—devastating disease in plants.
Fungi.
• Yeast—unicellular.
• Molds and mushrooms—multicellular.
Domain Archaea
Distinguished from Bacteria by unique rRNA gene sequences. Lack peptidoglycan in cell walls. Have unique membrane lipids. Some have unusual metabolic characteristics. Many live in extreme environments.
Spontaneous generation.
• Idea that living organisms can develop from nonliving or decomposing matter
Francesco Redi (1626 to 1697). • Discredited spontaneous generation.
Louis Pasteur - swan neck flasks
Gram negative
Gram negative ‐ peptidoglycan cell wall, surrounded by
an outer membrane containing lipopolysaccharide.
Gram negative ‐ three principal layers in the envelope;
the outer membrane, the peptidoglycan cell wall, and
the cytoplasmic or inner membrane
.
Gram positive
Gram‐positive ‐ lack an outer membrane, surrounded by layers of peptidoglycan many times thicker than is found in the Gram‐negatives
In Gram positives ‐ threading through these layers of
peptidoglycan are long polymers called teichoic acids
Chemotaxis
• Move toward chemical attractants such as nutrients, away
from harmful substances.
• Move in response to temperature, light, oxygen, osmotic
pressure, and gravity.
Gram stain reactions in cell wall
Gram stain reaction due to nature of cell wall.
Shrinkage of the pores of peptidoglycan layer of Gram‐
positive cells.
• Constriction prevents loss of crystal violet during
decolorization step.
Thinner peptidoglycan layer and larger pores of Gram‐
negative bacteria do not prevent loss of crystal violet.
• Alcohol may also remove/extract some lipids from outer layer of Gram‐negative cell wall, making crystal violet dye removal easier.
Steps of gram stain
Add crystal violet stain over the fixed culture. Let stand for 10 to 60 seconds; Rinse
Add the iodine solution on the smear, . Let stand for 10 to 60 seconds. Rinse
Add a few drops of alcohol, Rinse it off with water after 5 seconds.
Counterstain with basic fuchsin solution for 40 to 60 seconds, Rinse
Flagellar Movement
Flagellum rotates like a
• Very rapid rotation up to
1100 revolutions/sec.
• In general, counterclockwise
(CCW) rotation causes
forward motion (run).
• In general, clockwise rotation
(CW) disrupts run causing
cell to stop and tumble.
Chlamydia
Elementary body (EB) attaches to host cell.
- Reticulate body (RB) reproduction by binary fission.
- Differentiate back into EB, lyses cell.
Releases EB’s
Cycle repeats
Chlamydia Metabolism information
Cannot catabolize carbohydrates.
Cannot synthesize ATP or NAD+
. • Import up from host.
• Do have genes for substrate-level phosphorylation, electrontransport, and oxidative phosphorylation.
RBs have biosynthetic capabilities when supplied
precursors from host; can synthesize some amino acids.
EBs seem to be dormant forms.
Spirochete diseases.
Lyme disease
syphilis
Mycobacterium cell walls
Outer membrane contains mycolic acids
linked to peptidoglycan by arabinogalactan, a
polysaccharide.
- Cell walls very hydrophobic.
- Impenetrable by antibiotics.
Basic fuchsin dye not removed by acid
alcohol treatment.
• non-acid-fast bacteria easily decolorize
on the addition of the acid-alcohol and
take up the counterstain dye of
methylene blue and appear blue.
This technique identifies Mycobacterium
tuberculosis and Mycobacterium leprae
Mycobacterium types
M. bovis. • Tuberculosis in cattle, other ruminants, and
primates.
M. tuberculosis. • Tuberculosis in humans.
M. leprae. • Leprosy.
M. avium complex (MAC).
• Various diseases.
Streptomycetales
Provide us with antibiotics
Bifidobacteriales
Pathogens and Probiotics
Bacillus
Produce the antibiotics bacitracin, gramicidin, and polymyxin.
B. cereus—food poisoning.
B. anthracis—anthrax.
B. thuringiensis and B. sphaericus—used as insecticide
Three Groups of Streptococci
Pyogenic (pus producing) streptococci.
• For example, S. pyogenes—streptococcal sore
throat, acute glomerulonephritis, and rheumatic
fever.
Oral streptococci.
• For example, S. mutans—dental caries.
Other streptococci.
• For example, S. pneumoniae—pneumonia and otitis
media.
Prion diseases
TSE
Bovine spongeform
Kuru
Creutzfeld Jakob
Prions
Abnormaly folded proteins
Protists
Flagellated
lack mitochondria
some have mitosomes
Protozoa—wide
distribution in nature;
single-celled eukaryotic
chemoorganotrophs.
Naegleria fowleri
Protozoan
Amebic Meningoencephalitis
Muscosal Membranes: Ears,
Eyes, Nose, Genitals
Acanthamoeba spp.
Protozoan
Amebic Meningoencephalitis
Muscosal Membranes: Ears,
Eyes, Nose, Genitals
Entamoeba histolytica
Protozoan
Amebiasis
Intestinal tract
Trypanosoma brucei
Protozoan
African sleeping sickness
Blood
Plasmodium spp.
Protozoan
Malaria
Blood
Baltimore classification
7 groups
Double DNA Single DNA Double RNA Single RNA + Single RNA - Single RNA Reverse transcriptase (Retrovirus) Double DNA Reverse transcriptase
Double DNA
Baltimore classification Group
Mode of production:
mRNA is transcribed directly from the DNA template
Example:
T4 bacteriophage
Herpes simplex
Largest group of known viruses.
Most bacteriophages and archaeal viruses.
Single DNA
Baltimore classification Group
Single-Stranded DNA Viruses Use a Double-Stranded Intermediate in Their Life Cycles
Bacteriophage oX174
Double RNA
Baltimore classification Group
RNA-Dependent RNA Polymerase Replicates
the Genome and Synthesizes mRNA
Rotavirus
Single RNA +
Baltimore classification Group
Mode of production:
plus stranded
Example: Polio Zika Hep A Eastern Quine Encephalitis
Single RNA -
Baltimore classification Group
Mode of production:
Cannot serve as mRNA to form viral proteins
Must bring pre-formed RNA-dependent RNA polymerase into cell
Example: RSV Influenza Ebola Rabies
Single RNA Reverse transcriptase
Retrovirus
Baltimore classification Group
Mode of production:
Plus-Strand Viruses That Use Reverse Transcriptase in Their Life Cycles
Example:
HIV
Double DNA Reverse transcriptase
Baltimore classification Group
Mode of production:
Production of new virions takes place largely inside of liver cells (hepatocytes)
Example:
Hep B
Other protists and fungi
Fornicata Microaerophilic protist
Pathogenic Trichomonads
Trypanosomes—Pathogenic Euglenozoa
Entamoebida
Apicomlexans
Main types of mutations
Frameshift mutations
Chromosomal Mutations
Frameshift mutations
Addition or deletion
much more profound consequences
alter reading downstream frames
Huntingtons
Chromosomal mutations
Deletions (part of chromosome is lost)
Duplication (part is copied)
Inversion (part is reversed)
Translocation (part is moved)
Gram positive
Agar
Catalase test
C diff, MRSA, VRE (most common resistant)
Gram Negative
Oxidase
Agar
Broth
Campylobacter Cholera E coli influenza legionaires pertussis salmonella typhoid psuedomonas plague
Point mutation
Mutation of single base
sickle cell
Base substitution
Silent mutation (same AA is inserted) doesn't change function AAG - AAA
Nonsense mutation (codon changed to "stop" codon) AAG - UAG
Missense mutation (changes amino acid) differnet protein codon AAG - AGG Purine to Purine (Transistion) Purine to pyrimidine (transversion)
Haploid
1 set of chromosomes
Diploid
2 complete sets of chromosomes
Humans are diploid and have 46 total chromosomes
23 pairs
Dominant
The phenotype can be seen whe either homo or heterozygous
Recessive
The phenotype can only be seen if homozygous
Chargoff rules
A is equal to T
C is equal to G
Purines and pyrimidine are proportional
Purines are A & G
Pyrimidines are C & T
Rosalind franklin
Performed xray diffraction studies to ID 3D structures
Discoverd that DNA is Helical
Determined that the molecule has a uniform diameter
Blood Type
A+
A+ can receive from:
A+, A-, O+, O-
A+ can donate to:
A+, AB+
Blood Type
O+
O+ can receive from:
O+, O-
O+ can donate to:
O+, A+, B+, AB+
Blood Type
B+
B+ can receive from:
B+, B-, O+, O-
B+ can donate to:
B+, AB+
Blood Type
AB+
AB+ can receive from:
ALL (universal recipient)
AB+ can donate to:
AB+
Blood Type
A-
A- can receive from:
A-, O-
A- can donate to:
A+, A-, AB+, AB-
Blood Type
O-
O- can receive from:
O-
O- can donate to:
ALL (Universal Donor)
Blood Type
B-
B- can receive from:
B-, O-
B- can donate to:
B+, B-, AB+, AB-
Blood Type
AB-
AB- can receive from:
AB-, A-, B-, O-
AB- can donate to:
AB+, AB-
Blood type antibodies
Blood type has the antibody of the letter that is mssing
Examples Type A has B antibodies Type B has A antibodies Type O has A & B antibodies Type AB has no antibodies
DNA structure make up
5 carbon sugar
with a phosphate group attached
then 1 of 4 nitrogenous bases attached A,C,G,T
Hydrogen bonds hold the 2 starnds together lightly so they can be pulled apart in transcription
phosphodiester bonds join adjacent nucleotides
covalent bonds
DNA strand is coiled arounf 8 Histone proteins every 200 nucleotides
Polygenic traits
controlled by many genes
Pleiotrophy
the ability of a single gene to have multiple effects on phenotypes
Examples:
Hemophilia
Factor VIII deficiency
Lysogenic vs Lytic
Lysogenic=
Infected cell replicates creating new cells that are already infected
Lytic=
infected cell ruptures releasing infection to spread and infect new cells
Lysogenic cycle
Phage infects cell
Phage inserts self into Cells DNA
Cell replicates with New DNA in it
New replicated cells are already infected with modified phage DNA
Lytic cycle
Phage infects cell
Phage DNA circularizes
Host cell is used to make new phage DNA and Phage proteins
Phage eventually bursts and spreads new phages
(Primary way Phages replicate)
Proteobacteria
Gram negative
The largest phylogenetically coherent bacterial
group with more than 500 genera.
Class Alphaproteobacteria
Class Betaproteobacteria
Class Gammaproteobacteria
CLass Epsilonproteobacteria
Proteobacteria
Class Alphaproteobacteria
Gram negative
Most are oligotrophs.
Rickettsiales– Rocky Mountain Spotted Fever
Metabolically diverse.
• Methylotrophy, chemolithotrophs, nitrogen fixers
Proteobacteria
Class Betaproteobacteria
Gram negative
Considerable metabolic diversity.
Chemoorganotrophs, photolithotrophs, and
chemolithotrophs.
Neisseria gonorrhoeae—gonorrhea.
Neisseria meningitidis—some cases of bacterial meningitis.
Burkholderiales
Genus Bordetella
Proteobacteria
Class Gammaproteobacteria
Gram negative
Largest subgroup of proteobacteria.
• Contains 14 orders and 27 families
Very diverse physiological types.
• Chemoorganotrophs, photolithotrophs,
chemolithotrophs, methylotrophs
• Aerobic and anaerobic.
Genus Thiomicrospira
Genus Coxiella
Genus Legionella
Genus Pseudomonas
Escherichia coli
Order Vibrionales
Order Pasteurellales
Order Enterobacteriales Salmonella—typhoid fever and gastroenteritis. Shigella—bacillary dysentery. Klebsiella—pneumonia. Family Yersiniaceae Yersinia—plague.
Proteobacteria
Class Epsilonproteobacteria
Gram Negative
Smallest of proteobacterial classes.
Genus Campylobacter
Genus Helicobacter
Gram Positive bacteria
Actinobacteria Corynebacterium (diphtheria) Mycobacterium (tuberculosis, bovis, leprosy) Nocardia. Propionibacteriales (Acne) Streptomycetales: (scabies) Bifidobacteriales Bacillales Thermoactinomyces Staphylococcaceae Listeria Lactobacillales
