Medical Micro Bio Exam #1

"Lockjaw" is a symptom of infection with

Clostridium tetani

An allosteric inhibitor works by

Binding to a site other than the active site and causing a conformational change of the enzyme

The primary host of the West Nile virus is

Birds

An epidemic arising from a shared, contaminated water supply is a ___.

Common-source outbreak

When electrons are shared between two atoms, a ___ bond is generated.

Covalent

The presence of bacteria in the blood is referred to as _____.

Bactermia

Microorganisms possessing metabolic pathways that can function in the presence or absence of oxygen are describes as

Facultative anaerobes

True or False: Neutropenia refers to a type of anemia in which red blood cell numbers are lower than normal.

False; white blood cells

Microorganisms that normally colonize skin and mucous membranes are referred to as _____.

Flora

Atoms are the most stable when

Their outer shell is full of electrons

True o False: All 20 amino acids have three common chemical components attached to a central carbon. They are a hydrogen, a carboxylic acid group and an amino group.

True

True or False: Only one molecule of diptheria toxin is needed to kill a host cell.

True

True or False: Prions are resistant to standard autoclave treatment

True

Which of the following is a mismatched pair? a. Flavivirdae: dengue fever b. Rhabdoviridae: rabies c. Coronaviridae: SARS d. Filoviridae: Ebola hemorrhagic fever e. Bunyaviridae: cholera

e. Bunyaviridae: cholera

Which of the following explains the dramatic decrease in death rates attributed to infectious disease during the twentieth century? a. advances in public health b. chlorination of drinking water c. use of antibiotics d. effective vaccine programs e. all of the above

e. all of the above

Which of the following is NOT a characteristic of endotoxins? a. extremely stable at high temperatures b. induce fever in the host c. poor antigenicity d. located in the cell wall of Gram-negative bacteria e. lethal in small quantities

e. lethal is small quantities

Infectious dose 50% (ID50) refers to the number of organisms required ___.

for 50% of exposed individuals to show signs of infection

Mobile genetic elements that sometimes carry pathogenicity islands are known as

plasmids

Which of the following is a mismatched pair?

secondary infection: symptoms arise years after an initial infection

The reason for converting toxins to toxoids for vaccine use is _____.

to retain their antigenicity but destroy their toxicity

A disease that is transferred from animals to humans is called ___ with ___ serving as an example.

zoonotic; bubonic plague

The term _____ refers to diseases that persist in a population at low levels.

Endemic disease

___ is the term used by microbiologists to describe the underlying cause of a disease.

Etiology

Contact transmission may occur indirectly when a nonliving intermediate called a ___ is involved.

Fomite

True or False: Enzymes are not permanently charged by the reactions in which they participate

True

True or False: Only bacteria containing mycolic acid in their cell wall are acid-fast

True

The 5 requirements for a successful infection

1. Entry 2. Establishment 3. Defeat host defenses 4. Damage the host 5. Exit and transmission

Which of the following toxins inhibits the release of acetylcholine from neuromuscular junctions?

Tetanus

An appropriate stain for a sputum sample from a patient with tuberculosis is the _____ stain.

Acid-fast

The components of ATP include

Adenine, ribose sugar and three phosphates

The biosynthesis of glycogen using glucose building blocks involves a process known as

Anabolism

When a large complex molecule is broken down into smaller molecules, _____ has occurred.

Catabolism

Diseases that take a long period to develop and also remain for long periods are referred to as _____.

Chronic

An outbreak of food poisoning occurs at a family picnic after the growth of Staphylococcus aureus in unrefrigerated potato salad left sitting in the hot sun for several hours. Microscopic examination of the potato salad reveals _____.

Clusters of cocci

Bacteria which have a spherical or ovoid shape are called _____.

Cocci

___ refers to the release of water during the biosynthesis of biological molecules

Dehydration synthesis

_____ refers to the loss of protein three-dimensional structure when temperature or pH is altered.

Denaturation

If the incidence of a disease rises sharply above normally expected levels, then ___ has occurred.

Epidemic

The study of the factors responsible for the prevalence and transmission of infectious diseases is known as _____.

Epidemiology

___ bacteria lose their crystal violet when the decolorized alcohol is added during the Gram stain process

Gram-negative

Which of the following is a virus transmitted by animals and not humans?

Hanta Virus

_____ made by bacteria destroys red and white blood cells in the host.

Hemolysin

When widespread vaccination is administered to a population as a means of protecting unvaccinated potential hosts, _____ is achieved.

Herd immunity

The outcome of an infection is primarily dependent on _____, which, when adequately activated, eradicate the pathogen.

Host defenses

A phospholipid contains fatty acids that are ___ and therefore do not interface with water

Hydrophobic

If an individual's host defense is not functioning correctly, they are considered to be

Immunocompromised

Chickenpox can cause a rash known as shingles. This is an example of ___.

Reactivation

The number of new cases of a particular disease contracted within a defined population in a specified period is referred to as the _____ of the disease.

Incidence

Temperature, pain, redness and swelling are associated with

Inflammation

When an antibiotic targets a pathogen-specific component, it carries out _____.

Inhibition of a biochemical function that is unique to the pathogen

The location where infectious organisms can multiply and accumulate is referred to as the _____.

Resevoir

A disease that is acquired in a clinical setting is known as a(n) _____ infection.

Nosocomial

Organisms that exploit a host's decreased resistance to infection and cause disease are referred to as _____.

Opportunists

If an electron is released from an atom, an ion, or a molecule during a chemical reaction, then an ___ reaction has occurred

Oxidation

Locations where pathogens gain access to a host are referred to as _____.

Portals of entry

Infections with _____ are particularly problematic in burn patients.

Pseudomonas aeruginosa

When genome segments are rearranged or "re-shuffled" between two different viral strains infecting the same cell, this is called

Re-assortment

The ___ of SARS coronavirus is/are used to bind to receptors on the host cell membrane.

Spike proteins

If pathogens spread to the bloodstream or lymphatics and disseminate to other parts of the body, a ___ occurs.

Systemic infection

Which of the following is a mismatched pair? a. SARS: South America b. Ebola: Africa c. HIC: Africa d. Nipah: Malaysia e. Avian influenza: China

a. SARS: South America

Which of the following common pathogens is mismatched with the disease it causes? a. Bordetella pertussis; whooping cough b. Clostridium perfringens; tetanus c. Vibrio cholerae; cholera d. Plasmodium falciparum; malaria e. Treponema pallidum; syphilis

b. Clostridium perfringens; tetanus

Which of the following is commonly associated with tuberculosis? a. megasomes b. granulomas c. sepsis d. mutualism

b. Granulomas

Which of the following is not a characteristic of the Krebs cycle? a. aerobic metabolism b. directly acceptance of pyruvate, a three-carbon molecule, from the glycolysis pathway c. net production of ATP per one turn of the cycle d. oxidization of carbon to CO2 e. transfer of electrons to NAD+ and FAD

b. because pyruvate contains 3 carbons and it only accepts 2 carbons, so it must be modified before being accepted

Which of the following is not a biological molecule? a. carbohydrate b. carbon dioxide c. proteins d. lipids e. nucleic acids

b. carbon dioxide

Which of the following is not an explanation for the re-emergence of TB? a. failure of patients with TB to take all of their prescribes antibiotics b. an increase in the number of elderly living in nursing homes c. an increase in the rodent population in urban areas d. an increase in the number of immigrants born in areas where TB occurs e. the HIV/AIDS epidemic

c. an increase in the rodent population in urban areas

Which of the following is not associated with the portal of entry referred to as the parenteral route? a. contaminated needles used by drug users b. transmission of malaria by mosquitos c. fecal-oral contamination d. tick-derived Lyme disease e. blood products used by hemophiliacs

c. fecal-oral contamination

All of the following may be present in bacterial cells except

cilia