Lab exam review Flashcards
One of the most important human pathogens
Group A Streptococci
What bacteria are most frequent in humans? What does it cause?
Group A Streptococci
Pharyngitis and common cause of skin infections
What bacteria is colonized in the genetial tract of some women
Group B Streptococci (GBS)
what can Group B Streptococci cause in newborns?
neonatal meningitis and sepsis
Why do pregnant women get a GBS swab?
GBS+ women can pass the bacteria to their infants during delivery (very bad)
What are enterococci
normal flora of the colon
what happens if enterococci are found outside of the colon?
They can cause urinary, Biliary or cardiovascular infections
What 2 subtypes of bacteria make up Group D streptococci
Enterococci and non-enterococci
What does alpha-hemolytic streptococci look like on a blood agar plate? what does that indicate
Green
indicates partial hemolysis
What does beta-hemolytic streptococci look like on blood agar plate? what does that indicate?
clear
indicates complete hemolysis
What does gamma-hemolytic streptococci look like on blood agar plate? what does this indicate?
red
indicates no hemolysis
What causes beta-hemolysis
production of hemolysin enzymes (Streptolysin O and streptolysin S)
What are plasmids and bacteriophages
extra chromosomal DNA elements that replicate independent of the genomic DNA
what do plasmids and bacterophages allow?
exchange of genes between strains and types of bacteria
what do virulence genes do?
encode toxins or enzymes that help bacteria overwhelm host tissues and immunity or get nutrients
what are the four phases of the bacterial growth curve IN ORDER
- lag phase
- log phase
- stationary phase
- death phase
What is the lag phase on the bacterial growth curve
vigorous metabolic activity occurs
cells do NOT divide
lasts a few minutes to many hours
what is the log phase of the bacterial growth curve
rapid cell division
what is the stationary phase of the bacterial growth curve
nutrients deplete OR toxic products cause growth to slow
What is the death phase of the bacterial growth curve
decline in the number of viable bacteria
How do bacteria adapt to their environment
controlling gene expression
what is the most common way of altering gene expression
change the amount of mRNA transcription
Describe the 4 phases of bacteria cell division
- cell elongates and DNA replicates
- cell wall and plasma membrane begin to divide - formation of a septum in the middle of the cell (cross wall)
- Cross wall forms completely around divided DNA
- cells separate
Describe how Glucose becomes ATP
- glucose
- pyruvate –> can ferment into 2 ATP + acids and alcohols
- Acetyl CoA
- Krebs cycle
- Electron Transport chain
IN THE PRESENCE OF O2 - 38 ATP, CO2, H2O (aerobic respiration)
OR
IN THE PRESENCE OF INORGANIC COMPOUNDS - 34 ATP (anaerobic respiration)
What are two bacterial enzymes for normal functions or to resist immune cells?
Catalase and Coagulase
how does catalase work?
converted hydrogen peroxide into water and oxygen to undermine immune cells
how does coagulase work
forms a clot around the bacteria to protect it from immune cells
does pathogenic staphylococcus have coagulase?
YES
does non-pathogenic staphylococcus have coagulase?
NO
what acid does gram+ bacteria have that gram- does not?
Teichoic acid
T or F
gram+ bacteria have an outer membrane
False
only gram- bacteria have an outer membrane
T or F
Both gram+ and gram - bacteria have peptidoglycan AND periplasmic space
False
both have peptidoglycan BUT only gram- has periplasmic space
what are the major functions of plasma membrane proteins (5)
- selective permeability and transport of solutes
- electron transport and oxidative phosphorylation, in aerobic species
- excretion of hydrolytic exoenzymes
- enzymes
- receptors and other proteins
describe the cell wall of gram- bacteria from superficial to deep
- Outer membrane (LPS and protein)
- peptidoglycan
- plasma membrane
describe the cell wall of gram+ bacteria from superficial to deep
- peptidoglycan
- periplastic space
- plasma membrane
where is the cell wall located in relation to the cytoplasmic membrane
external
how does the outer membrane change depending on bacteria type
it may vary in thickness and chemical composition
what are the two layers outside the peptidoglycan layer in gram- bacteria
periplasmic space and outer membrane
what is the outer membrane made of
lipoprotein and lipopolysaccharide (LPS)
what does the outer membrane prevent
the passage of large macromolecules
how are bacteria classified into positive or negative
cell wall composition
what does the cell wall provide (3)
protection
plays essential role in cell divison
shape (cocci, rods or spirochaetes)
What does gram stain bind to?
peptidoglycan in cell wall
what is the staining chemical?
Crystal violet
What are faculative anaerobes?
can grow with or without O2
example of a faculative anaerobe found in normal gut commensal
E. Coli
is harmless in get but pathogenic elsewhere
What is an obligate aerobe
bacteria that need O2 to grow and perform aerobic metabolism
What obligate aerobe exists on humans
Staphylococcus epidermis
lives on our skin
what are Anaerobes
Bacteria that do NOT need O2
most vaginal/gut flora
what is an obligate anaerobe
must NOT have any O2 to prosper
what thre shapes can bacteria be classified into
cocci, Bacilli, spirochetes
describe cocci
small spherical shapes
describe bacilli
small elongated shape
describe spirochetes
long, curved, bent
what are the 3 ways cocci can be named by their arangment
Diplococci, streptococci, staphylococci
describe diplococci
in pairs
describe streptococci
in chains
describe staphylococci
in grapelike clusters
what are general characteristics of bacteria
most are less than 1 micrometer
most abundant organisms
most tolerant of environmental conditions
what is only bacteria that is not less than 1 micrometer
Bacillus anthracis
Large gram+
ranges from 3-10 micrometers
Describe a prokaryote
no nucleus, genomic DNA in single chromosome
have plasmids to carry DNA and self replicate
transcription and translation happens simultaneously from genomic DNA
cell membrane covered by thick cell wall and lipid layers
Describe a Eukarote
DNA carries in several chromosomes in membrane bound nucleus
translation from mRNA takes place on ribosomes
cytoplasm is rich in organelles
single plasma membrane
what doe the pH scale measure
concentration of H+ ions
is a pH of 14 acidic or alkaline
alkaline
what is the normal pH range of urine?
8-5
what is the normal pH range of blood
7.35-7.45
where are ionic bonds found in the body?
tissues and electrolytes
what do ionic bonds give strength to
teeth and bones
where do most ions stay in the body
watery fluid (ie. blood)
what is an electrolyte?
substace that breaks into pos/neg ions when disolved in water or body fluids
why are electrolytes important
regulate nerve and muscle function
hydration
balance blood pH
blood pressure
Describe a covalent bond
most common and strong chemical bond in living organisms
forms when a pair of electrons is shared between 2 atoms
describe a double covalent bond
2 atoms share 2 pairs of electrons
stronger than a single covalent bond
common in molecules where atoms need more than one pair of electrons to complete outer shell (Oxygen)
what is proteinuria/ what does it indicate? in pregnancy?
high protein in urine
kidney diseases
pregnancy induced hypertension
what does high glucose in urine indicate? in pregnancy?
diabetes, kidney disease
GDM
What does high ketones in urine indicate?
Diabetes, anorexia or low carb diet
wha does high urobilinogen in the urine indicate?
Hemolytic or pernicious anemia, hepatitis
what is urobilinogen?
waste product from degraded hemoglobin
what does high billirubin in urine indicate>
liver disease
what does nitrite in the urine indicate
UTI
What does hemoglobin or RBCs in urine indicate?
kidney disease, infection, trauma or tumors
what does WBC in urine indicate
infection along the urinary system
what is Rh incompatability
if an Rh- woman carries an Rh+ fetus during her first pregnancy, Rh+ antibies can enter her blood stream during delivery.
During later pregnancies, with an Rh+ fetus IgG antibodies can cross the placenta and cause lysis of fetal RBC
what is the formal name for lysis of fetal RBC due to Rh incompatability
hemolytic desiease of the newborn or erythroblastosis fetalis
what Rh blood type is cause for concern if the other biological parent blood type is positive
Rh-
describe the structure and function of RBCs
no nucleus, full of hemoglobin
Oxygen and CO2 transport between lungs and tissues
describe the structure and function of WBCs
nucleated, multiple types and functions related to inflammation and immune protection of tissues
describe the structure and function of platelets
no nucleus
activated to allow clotting by producing clotting factors during bleeding
describe WBC count
typically given as a percentage of total blood cells
usually 0.1% of blood
marker of infection
describe hematocrit
fraction of whole blood volume occupied by RBC
usually 40-45% of blood volume
What is anemia
RBC deficiency
what is polycythemia
RBC too high
who can type A donate to/receive from
Donate: Type A, AB
receive: Type A, O
who can type B donate to/receive from
Donate: B, AB
Receive: B, O
who can type AB donate to/receive from
Donate: AB
Receive: all
Who can type O donate to/receive from
Donate: All
receive; O
what are the 5 WBC subsets
Neutrophil, Lymphocyte, Monocyte, Eosinophil, Basophil (never let monkeys eat bananas)
frequency and function of neutrophil
60-70%
phagocytosis and inflammation
frequency and function of Eosinophil
2-4%
control allergic reaction, combat nematodes
Frequency and function of basophil
2-4%
increase allergic reaction
Frequency and fucntion of lymphocyte
20-40%
mediate innate and adaptive immune responses
Frequency and function of monocyte
3-8%
Phagocytosis, differentiate into macrophages
