Micro Unit 3

What does ATP stand for? What are the main chemical groups in ATP?

**Adenosine triphosphate (ATP) **Adenosine triphosphate is made of adenine, ribose, and three phosphate groups

Define enzyme, catalyst, and reaction rate. What is the purpose of ligase and lipase?

**Enzymes- are protein catalysts that help chemical reactions occur under cellular conditions **Catalyst- an organic or inorganic substance that is only needed in small amounts to make a reaction happen faster; it is not consumed or permanently changed by a reaction. **Reaction rate- the speed at which the reaction occurs --------------------------------------------------------- --Ligase(class) joins two molecules usually using energy examples dna ligase -Lipase helps break down fat in foods (class hydrolase and it performs hydrolysis which is the addition of water to break bonds)

Define metabolism. Distinguish between catabolism and anabolism. Indicate which one absorbs energy (endergonic) and which one releases energy (exergonic)

**Metabolism - chemical reactions that organisms use to break down substances to release energy as well as reactions that use the released energy to build new substances. **Catabolic pathways break down substances and release energy. Releases energy or exergonic. **Anabolic pathways combine energy and molecules to build new substances. Absorbs energy or endergonic.

Differentiate between aerobic and anaerobic processes

*Aerobic respiratory chains are used in aerobic cellular respiration, and require oxygen as a final electron acceptor *Anaerobic respiratory chains are used in anaerobic cellular respiration, and use an inorganic substance other than oxygen as their final electron acceptor—nitrite or nitrate, for example

State why healthcare settings are hot zones for antibiotic-resistant pathogens and the role of epidemiology in managing such resistance.

--"Superbug" HAIs drug-resistant pathogens often originate in healthcare settings due to extensive antibiotic use --Important aspect of hospital epidemiology is monitoring antibiotic-resistant strains --Hospital microbiologists routinely test isolated pathogens for their antibiotic susceptibility --Susceptibility is then shared with the healthcare team to make informed decisions about treatment

In your own words, describe the major roles of public health.

--Accurate public education is central to breaking the epidemiological triangle --Examples of public health education include: *Vaccination campaigns *Promotion of prenatal care and breast-feeding *Education about sexually transmitted diseases --Public health education can help people understand their role in preventing development of drug-resistant pathogens

Describe how rates, proportions, and ratios may be used to describe disease.

A rate is used to measure the occurrence of an event over time. A ratio presents the occurrence of an event in one group as compared to another group (in the United States in people age 65 and older there are 0.77 male/female). A proportion is a percentage of a whole (80 out of 100 women with gonorrhea do not have symptoms, or 80 percent of women with gonorrhea do not have symptoms).

Describe the various direct and indirect modes of transmission and provide examples of each.

DIRECT 1. person to person; skin contact and directly contacting bodily fluids or excrement saliva: mono touching: MRSA sex: HIV, chlamydia --------------------------------------------------------- 2. animal; bite or scratch bite: rabies touching: cat scratch fever --------------------------------------------------------- 3. environment; pathogen resides in an environmental source swimming: swimmers ear soil: anthrax bacteria enters a cut --------------------------------------------------------- 4. vertical; from mother to child in utero: HIV vaginal delivery: group B streptococci --------------------------------------------------------- INDIRECT 1. airborne; airborne particles carry pathogens respiratory aerosols: measles windborne: histoplasmosis stirred up animal droppings: hanta virus --------------------------------------------------------- 2. vehicle; the pathogen is introduced to a host through contact with contaminated objects foodborne: salmonella contaminated needles: HIV contaminated water: cholera --------------------------------------------------------- 3. biological vector; pathogen has part of its life cycle in an insect mosquito bite: malaria tick bite: lyme disease flea bite: plague --------------------------------------------------------- 4. mechanical vector; pathogen "hitches a ride" but does not have part of its life cycle in the vector flies: land on dog feces then on lunch cockroaches: scurry through garbage then on food

What does the word "rate" mean?

used to measure the occurrence of an event over time

Describe the different ways you can collect, isolate, count, and identify microbes

*Collect microbes by using aseptic techniques and sterile materials. The properties of the suspected causative agent must also be considered during sample collection in order to collect the sample the correct way and use the correct equipment. Sample might need to be refrigerated or placed on dry ice to ship. --------------------------------------------------------- *Isolating microbes by streak plate technique. To identify the potential pathogen in a clinical sample it must first be separated from other organisms in the sample. Method dilutes a culture on an agar plate, individual cells are thinly separated from one another over the medium's surface, and as cells divide, their population increases to form a mound of cells called a colony --------------------------------------------------------- *Counting microbes by DIRECT methods. These methods involve counting individual cells or colonies (plate counts). As the name implies, a cell count enumerates the number of cells in a small portion of the sample. Cell counts can be done using automated or manual procedures. (EX: microscopic count, coulter counter or flow cytometer, viable plate count) *INDIRECT methods: Indirect methods rely on secondary reflections of overall population size. (EX: turbidity measurement, dry weight, and biochemical activity) --------------------------------------------------------- *Identifying microbes: Physical, biochemical, and genetic analysis are all commonly used tools to identify microbes. ---Physical analysis involves staining and microscopy to observe morphological features --Biochemical analysis involves a collection of media that assess metabolic properties --Genetic methods also help to quickly identify microbes -Probes, PCR, DNA "fingerprinting," electrophoresis separation methods

Describe each reaction involved in oxidation and reduction. Explain why these reactions are referred to as "redox" reactions

*In an oxidation reaction, an atom or molecule loses electrons (e−). *In a reduction reaction, an atom or molecule gains electrons. *Oxidizing agents carry out oxidation reactions. Reducing agents carry out reduction reactions. *Redox reactions involved oxidation and reduction reactions --Oxidizing agents carry out oxidation reactions --Reducing agents carry out reduction reactions *These always occur as partners in redox rxns

List the ways to control mycobacterium, endospores, viruses, protozoans, and prions

*Mycobacterium Control --Mycobacterium species cause tuberculosis and leprosy --Contain cell walls rich in waxy mycolic acids --Spread by airborne droplets --So control measures target reducing airborne particles from infected individuals --------------------------------------------------------- *Endospore Control --Endospores are dormant structures --Can revert to growing (vegetative) cells once favorable growth conditions are restored --Endospores survive drying, radiation, boiling, chemicals, and heat treatments --Most effective way to ensure elimination of endospores is by autoclaving --Other methods include hydrogen peroxide vapor at high heat or sporicides --------------------------------------------------------- *Viral Control --Viruses can be resistant to some measures --Lipids in the viral envelope are sensitive to heat, drying, and detergents --Glutaraldehyde-based detergents are effective at inactivating these viruses --Naked viruses are usually inactivated by chlorine-based agents --------------------------------------------------------- *Protozoan Control --Different stages of a protozoan's life cycle can resist certain control methods --Variety of treatments are used (e.g., filtration, carbon dioxide, UV and ozone treatments) --------------------------------------------------------- *Prion Control --Infectious proteins called prions --Withstand autoclaving and chemical sterilization --Surgical devices are reused after autoclaving or chemical sterilization --Prions are eliminated through a combination of chemical treatments and increased temperature and pressure during autoclaving

Explain how surveillance for nationally notifiable diseases (NNDSS) works. (Figure 9.11)

*National Notifiable Diseases Surveillance System (NNDSS) --Network of local hospitals, laboratories, and private healthcare providers --Monitor and report certain diseases --States have laws requiring reports of certain diseases to a local health authority --The diseases on a state or local tracking list are called reportable diseases *After a reportable disease is diagnosed... --It is documented per state or local rules --Case reports trickle up the local and state reporting chain to the CDC --National statistics are compiled

Describe ways to control microbial growth

*Physical controls such as temperature changes, radiation, and filtration TEMPERATURE- --Both cold and heat have important roles in controlling microbial growth --Refrigeration (4°C) and freezing (0°C) slow the growth of microbes -Slows food spoilage -In the lab, used to preserve specimen isolates and increase the shelf life of media -Refrigeration preserves clinical samples --Most microbes are sensitive to heat --Heat can be used to achieve either sterilization or decontamination (autoclave, boiling, pasteurization, dry heat) --------------------------------------------------------- RADIATION- --Some physical decontamination methods involve radiation, or high-energy waves --Radiation can serve as a disinfection or sterilization tool depending on the protocol -Radiation is either ionizing or non-ionizing --------------------------------------------------------- FILTRATION- --Large volumes of liquid or air can be passed through microbe-capturing filters --Filter pore sizes can even be made small enough to remove viruses --High-efficiency particulate air (HEPA) filters remove microbes and allergens from the air --Liquids can be sterilized using membrane filters --LifeStraws are 0.2 mm filters that remove pathogens from drinking water --------------------------------------------------------- GERMICIDES- --Chemical control of microbial growth --Germicides that kill microbes are classified as microbiocidal --Germicides that only inhibit microbial growth are microbiostatic *EX: Alcohols, Aldehydes, Phenols, Halogens, Peroxygens, Ethylene Oxide, Detergents

Explain this statement, "... all cells depend on redox reactions to make ATP."

*Redox reactions of catabolic pathways are often tied to phosphorylation reactions that recharge ADP to ATP

Define what an emerging disease is and how it differs from a reemerging disease and describe factors that contribute to disease emergence and reemergence.

--Emerging diseases are new or newly identified infections in a population --Factors contributing to the increase of emerging diseases include: -Population crowding -Poverty -Tropical climates -Diverse wildlife -Deforestation -Urbanization --------------------------------------------------------- --Reemerging diseases were previously under control, but are now showing increased incidence --Associated with pathogens that have evolved increased virulence (e.g., antibiotic resistance) --There's a much larger population of immune-suppressed people in the world today (e.g., AIDS patients, cancer patients, donor organ transplant recipients, and the elderly)

State how an emerging pathogenic disease is different from a reemerging pathogenic disease.

--Emerging pathogens include newly identified agents as well as pathogens that previously caused only sporadic cases (e.g., Zika) --Reemerging pathogen is an infectious agent that was under control but is now resurfacing (e.g., antibiotic resistance bacteria)

Explain the differences between a pandemic and an epidemic.

--Epidemic is a widespread disease outbreak in a particular region during a specific time frame --Pandemic occurs if an epidemic spreads to numerous countries

Explain why epidemiological measures are useful.

--Epidemiologists rely on numerical measures --Measures of frequency give information about the occurrence of a disease in a population during a certain period of time --To determine the impact and risk factors of an infectious disease, epidemiologists rely on numerical measures.

Define eradication and name factors to consider in an eradication program.

--Eradication of an infectious disease means that there are no longer any cases of it anywhere in the world --Best candidates for eradication are: -Easily identifiable -Treatable or preventable -Humans-specific --Note: Pathogens that can cause latent infections are harder to eradicate

Describe the factors to be considered in order to select an appropriate germicide

--Item uses --Germicide reactivity --Germicide concentration and treatment times --Types of infectious agents being controlled --Presence of organic and inorganic matter --Impact of germicide residues on equipment use --Germicide toxicity

Differentiate between the types of media and when they would need to be used and an example for each

--Liquid media are ideal for growing large batches of microbes (broth media) --Solid media are useful for isolating colonies and observing specific culture characteristics --Semisolid media is useful for motility testing (Solid and semisolid media in Petri plates) and (Solid and semisolid media in slants and tubes) --------------------------------------------------------- --Defined media also called synthetic media, are useful for growing certain autotrophs and some heterotrophs (Glucose minimal salts media) --Complex media also called enriched media, are used to grow fastidious organisms with complex growth requirements (Luria-Bertani Media) --------------------------------------------------------- --Differential media is formulated to visually distinguish one microbe from another (Blood agar) --Selective media single out bacteria that have specific properties (Mannitol salt agar (MSA) Eosin methylene blue agar (EMB)) --------------------------------------------------------- --Anaerobic media is used to grow anaerobes from a clinical specimen (anaerobic chamber)

Compare and contrast the following sets of terms: opportunistic pathogen versus true pathogen; communicable versus noncommunicable disease; acute versus chronic disease; and endemic versus sporadic disease

--Opportunistic pathogens only cause disease when their host is weakened (e.g., weak immune system) --True pathogen does not require a weakened host to cause disease --------------------------------------------------------- --Communicable diseases transmit from human to human --Noncommunicable do not spread from human to human --------------------------------------------------------- --Acute diseases have a rapid onset and progression --Chronic diseases have slower onset and progression --------------------------------------------------------- --Sporadic describes a disease that causes occasional infections in a population(ebola) --Endemic describes infections that are routinely detected in a population or region(head colds)

Define the terms population, morbidity, and mortality

--Population: any defined group of people --Morbidity: existence of disease in a population --Mortality rate: indicates number of deaths during a specific time period

Define quarantine and explain when it may be an effective tool to limit disease

--Some diseases with short incubation times can be controlled with quarantine *Period of confinement away from the general population

Describe an enzyme cofactor.

--Some enzymes need additional components to function; these helpers are called cofactors. Cofactors are nonprotein agents that some enzymes require to carry out a reaction. Cofactors do not necessarily affect whether a substrate can bind to the enzyme, but they are often required for the actual chemical reaction to occur. --Iron, zinc, magnesium, and calcium ions are examples of inorganic cofactors that may help catalyze a reaction by forming a bridge between the enzyme and a substrate. Many trace elements also act as inorganic cofactors. Organic cofactors are typically called coenzymes. They are nonprotein factors that range from free molecules that can move about to factors anchored to the enzyme they assist. Coenzymes are often vitamins or are made from vitamins

Describe an enzyme-substrate interaction

--When an enzyme and its substrate come together, it forms an enzyme-substrate complex --Site where the substrate binds the enzyme is the active site --Enzymes are flexible and mold to the substrate by the induced fit model --Enzyme-substrate complex allows the chemical reaction to occur by: -Properly positioning the reactants -Providing the activation energy required to start a chemical reaction -Stabilizing the transition state of the reaction

Provide an explanation of how ethical issues can emerge in epidemiology

--when a study is constructed to put people at serious risk --if a clinical trial for drugs is continued after data shows evidence of harm to participants --if genetic information is used to discriminate against patients

Describe the four phases illustrated in the bacterial growth curve

1. LAG PHASE- cells adjust to their environment 2. LOG PHASE- exponential cell growth 3. STATIONARY PHASE- number of cells dividing = number of cells dying 4. DEATH PHASE- cells die as waste accumulates and nutrients are depleted

List the 4 steps (in order) for aerobic respiration. What is the purpose of each step? How many ATPs are generated from one glucose molecule in aerobic respiration? What purpose does oxygen serve in aerobic respiration?

1. Glycolysis- It extracts energy from complex carbohydrates such as starches, from disaccharides like sucrose and lactose, and from simple sugars such as mannose, fructose, and of course, glucose. The word glycolysis means splitting of sugar. --------------------------------------------------------- 2. An intermediate step- the pyruvic acid made in glycolysis proceeds to the intermediate step, which converts both molecules into acetyl-CoA and also releases carbon dioxide --------------------------------------------------------- 3. Krebs cycle- The Krebs cycle (also called citric acid cycle) is a series of redox reactions and decarboxylation reactions in which carbon dioxide is removed --------------------------------------------------------- 4. Electron transport chain- Electron transport (respiratory) chains carry out coordinated redox reactions that transfer electrons from donor molecules to acceptor molecules --------------------------------------------------------- 38 ATP molecules are generated from one molecule of glucose --------------------------------------------------------- oxygen is the final electron acceptor in aerobic respiration. The oxygen that is so central to aerobic respiration is eventually reduced to water (H2O).

Briefly explain the five stages of infectious disease and summarize how these stages vary transmission from one pathogen to another.

1. Incubation period- the time between infection and the development of symptoms 2. prodromal phase- early symptoms to develop 3. acute phase- the peak of the disease; patient experiences full blown symptoms 4. period of decline- replication of the infectious agent is brought under control and symptoms start to resolve 5. convalescent phase- the patient recovers; in some cases the pathogen is kept latent in the patient

5. Differentiate between the six different categories of pathogens. As you differentiate, please include the following: a. pathogenic group name (agent of pathogenicity), b. whether it is eukaryotic, prokaryotic, or not a cell, c. whether the pathogen is multicellular, unicellular, or name the type of infectious substance, and d. provide an example of each.

1. helminths, eukaryotic, multicellular, hookworm 2. protozoans, eukaryotic, unicellular, malaria 3. fungi, eukaryotic, unicellular, athletes foot 4. viruses, not cells, infectious particles containing nucleic acids, chicken pox, measles, AIDS, rabies 5. prions, not cells, infectious proteins that do not contain DNA or RNA, rare sporadic diseases such as kuru and mad cow disease

How does ATP function as an energy source within the cell?

ATP is made by catabolic reactions and provides the energy for anabolic reactions. ATP is not something cells can save up, like dollars in a bank account. ATP is made on demand because cells use so much that they could never effectively store enough.

Differentiate between budding, binary fission, and spore formation

BUDDING- asexual reproduction in certain fungi and some bacteria. The bud formed is not an equal sized division of the original mother cell --------------------------------------------------------- BINARY FISSION- asexual form of reproduction used by most prokaryotic cells. starts as one parent cell and becomes two identical daughter cells --------------------------------------------------------- SPORE FORMATION- a form of reproduction used by some fungi and in fungi spores it can be sexual or asexual. in bacteria it is asexual

List the most common classes of HAIs and give examples of pathogens that cause them.

Bacteria cause: c. diff, e. coli, MRSA, VRE Viruses cause: hep b, HIV, Influenza, viral gastroenteritis Fungi: aspergillus mold species, candida yeast species

Write and label the reaction for cellular respiration. What is the product that directly provides energy for cellular work? What are the waste products in cellular respiration?

C6 H12 O6 + 6O 2 ---> 6CO 2 + 6H2O + 38 ATP glucose + oxygen --> carbon dioxide + water + ATP --------------------------------------------------------- ATP directly provides energy for cellular work and the waste products are carbon dioxide and water.

Define epidemiology and state its two primary goals.

Epidemiology- branch of medicine that aims to understand and prevent illnesses in communities --------------------------------------------------------- The two general goals of epidemiology are to: --describe the nature, cause, and extent of new or existing diseases in populations --intervene to protect and improve health in populations

Swim suit season is coming up, so you lose 10 pounds. Where did it go? Explain. (Big Picture)

Fat is basically stored energy. Your body converts fat to useable energy for your muscles and other tissues through a series of complex metabolic processes. This causes your fat cells to shrink.

Differentiate between phototrophs and chemotrophs, heterotrophs and autotrophs

Heterotrophs- require an external source of organic carbon such as sugars, lipids, and proteins --------------------------------------------------------- Autotrophs- do not require an external source of organic carbon and use carbon fixation to convert inorganic carbon into organic carbon --------------------------------------------------------- Phototrophs- are organisms that use light energy --------------------------------------------------------- Chemotrophs- are organisms that break down chemical compounds for energy

Where within a eukaryotic cell does each part of the aerobic cellular respiration reaction occur? Where in the Prokaryotic cell does each part of the reaction occur?

In prokaryotic cells- --In cytoplasm: glycolysis, intermediate step, and Krebs cycle --in plasma membrane: electron transport chain --------------------------------------------------------- In eukaryotic cells- --In cytoplasm: glycolysis --in mitochondria: intermediate step(matrix), Krebs cycle(matrix), and electron transport chain(inner membrane)

Explain the importance of Koch's postulates of disease to microbiology. Also, name five limitations of Koch's postulates.

Koch's postulates are important because they allowed us to identify the causative pathogens of many infectious diseases --------------------------------------------------------- Limitations of Koch's postulates: --Do not apply to noninfectious diseases --Certain infectious diseases cannot be isolated *Infectious agents that won't grow in the lab *Obligate intracellular pathogens --Some microbes become attenuated in pure cultures --Some microbes do not infect non-human hosts

Identify pathogens in the human body and their oxygen use

LUNGS: LUNGS: -Bordetella pertussis (whooping cough): obligate aerobe -Mycobacterium tuberculosis: facultative anaerobe -Mycoplasma pneumoniae: obligate aerobe --------------------------------------------------------- BLOOD AND LYMPH: -Borrelia burgdorferi (lyme disease): microaerophile -Treponema pallidum (syphilis): microaerophile -Yersinia pestis (plague): facultative anaerobe --------------------------------------------------------- SKIN: -Staphylococcus aureus (staph infection): facultative anaerobe -Propionibacterium acnes: aerotolerant anaerobe --------------------------------------------------------- STOMACH: -Helicobacter pylori (ulcers): microaerophile --------------------------------------------------------- LARGE INTESTINE: -Clostridium difficile: obligate anaerobe -Salmonella species: facultative anaerobe

Briefly describe Lactic Acid and Alcohol fermentation. Does fermentation require oxygen? Is fermentation a part of cellular respiration? Where does each occur? What products are produced in each type of fermentation?

Lactic acid fermentation can be described as being either homolactic or heterolactic. --In homolactic fermentation, the pyruvic acid made in glycolysis is only reduced to lactic acid. --Heterolactic fermentation results in the production of equal quantities of lactic acid, ethanol, and carbon dioxide, with minor amounts of acidic end products such as acetic acid and formic acid. --------------------------------------------------------- Fermentation does not require oxygen. --------------------------------------------------------- Although carbohydrate fermentation works in combination with glycolysis, fermentation is not considered part of cellular respiration --------------------------------------------------------- Lactic acid fermentation occurs in human muscle cells and alcohol fermentation occurs in yeast cells. --------------------------------------------------------- homolactic fermentation --> lactic acid heterolactic fermentation --> lactic acid, ethanol, and carbon dioxide with minor amounts of acidic end products alcohol fermentation --> ethanol and carbon dioxide mixed acid fermentation --> ethanol and acids butanediol fermentation--> butanediol

Compare and contrast biological and mechanical disease vectors.

Many arthropods such as mosquitoes and ticks act as biological vectors, meaning the vector organism has a role in the pathogen's life cycle. For example, the protozoan that causes malaria conducts the first part of its life cycle in mosquitoes and completes it in humans. In contrast, a mechanical vector spreads disease without being integral to a pathogen's life cycle. For example, a fly could pick up bacteria on its legs when it lands on garbage, then transfer those bacteria to your picnic lunch. Flies, rodents, and cockroaches are notorious mechanical vectors.

How do electrons get from glycolysis, the intermediate step, and the Krebs cycle to the electron transport chain?

NADH and FADH2 transport electrons to the ETC

At the end of the electron transport chain, what compound is reduced by electrons to form water?

Oxygen (O2)

Calculate the prevalence rate and incidence rate of a given disease. What do these values mean for each type of rate?

Prevalence Rate= Total cases in a defined population during a given time --------------------------------------------------------- Total people in the defined population during the same time Incidence Rate= Total new cases in a defined population during a specified time --------------------------------------------------------- Total susceptible hosts in the population during the same time --A jump in incidence could point to a new strain of influenza.

Match the type of bacteria with various growth conditions

Psychrophiles- can thrive between about −20°C and 10°C. These organisms tend to live in environments that are consistently cold, like the Arctic. --------------------------------------------------------- Psychrotrophs- grow at about 0-30°C, and are associated with foodborne illness because they grow at room temperature as well as in refrigerated and frozen foods --------------------------------------------------------- Mesophiles- prefer moderate temperatures and tend to grow best around 10°-50°C, a range that includes body temperature. Thus, most pathogens are part of the mesophilic temperature group. --------------------------------------------------------- Thermophiles- prefer warm temperatures of roughly 40-75°C. They dwell in compost piles and hot springs. --------------------------------------------------------- Extreme thermophiles- They prefer growth temperatures from 65-120°C. These organisms can live in boiling water and volcanic vents. --------------------------------------------------------- Barophiles- bacteria that can withstand high barometric pressure environments, such as occurs in the deep sea --------------------------------------------------------- Acidophiles- can grow at pH 1 (or less) to pH 5, and live in areas such as sulfur hot springs and volcanic vents. --------------------------------------------------------- Neutralophiles- grow best in a pH range of 5-8. They make up the majority of microorganisms, especially pathogens, known today --------------------------------------------------------- Alkaliphiles- are microbes that grow in the basic pH range of 9-11. They live in areas of the world that have extremely basic pH conditions, such as soda lakes that contain high concentrations of sodium carbonate. --------------------------------------------------------- Halophiles- organisms that thrive in high salt environments. These microbes tolerate environments that are up to 35 percent salt and can thrive in places like the Dead Sea and the Great Salt Lake of Utah. --------------------------------------------------------- Extremophiles- organisms that live in extremes of pH, temperature, and/or salt, and are exposed to a combination of stresses. --------------------------------------------------------- Facultative halophiles- Tolerate higher salt but may not grow well

Define the terms source, reservoir, and transmission and contrast endogenous and exogenous sources and provide an example of each.

Source- the animate or inanimate habitat which disseminates the agent from the reservoir to new hosts --------------------------------------------------------- Reservoir- the animate or inanimate habitat where the pathogen is naturally found --------------------------------------------------------- Endogenous source means the pathogen came from the host's own body ex. misplaced normal microbiota- bacteria living on skin can enter surgical incisions to cause post-op infections --------------------------------------------------------- Exogenous source means the pathogen is external to the host ex. humans- transmit communicable infections from one person to another

Clostridium botulinum is the Gram+ anaerobic bacterium that causes the food poisoning disease botulism. Even though it is anaerobic, it is common in soil and water and on plants. Explain how this is possible.

Spores produced by the bacteria clostridium botulinum are heat resistant and exist widely in the environment.

Chapter 8

Starts here

Describe the environmental factors that influence prokaryotic growth

TEMPERATURE- too hot speeds enzyme reactions up and too cold slows enzyme reactions down. too hot or cold can both kill growth. Because microbes cannot regulate their internal temperature in response to their surroundings, they must instead create proteins and membranes that function within a particular temperature range. temp where cellular growth rate is highest is optimal temp. --------------------------------------------------------- pH- While microbes can't regulate their internal temperature, most can adjust their intracellular pH in response to slight environmental pH shifts. This is an important capability for microbes to have because even small changes in extracellular pH, which will occasionally occur in any natural setting, can adversely affect cellular processes. In contrast to microbes that live in neutral (or nearly neutral) pH environments, those that live in pH extremes must constantly work to stabilize their intracellular pH and therefore have evolved specialized adaptations. --------------------------------------------------------- HIGH SALT CONDITIONS- These microbes tolerate environments that are up to 35 percent salt and can thrive in places like the Dead Sea and the Great Salt Lake of Utah. One challenge these bacteria must overcome is the stress that a high-salt environment puts on their water balance. Because bacterial cytoplasm is 80 percent water, cells in a high-salt environment will undergo plasmolysis—a situation in which water is drawn out of their cytoplasm into the solute-rich environment. --------------------------------------------------------- OXYGEN REQUIREMENTS- many microbes on this planet live either without oxygen or with minimal oxygen. Oxygen levels are much lower beneath the soil or within silt deposits deep in lakes and oceans than they are at Earth's surface. Most pathogens also thrive in low-oxygen environments within the host. Atmospheric oxygen (O2) easily diffuses across cell plasma membranes. Once inside the cell, some of the oxygen is converted into reactive oxygen species (ROS)

Describe the factors affecting enzyme activity: a. Temperature b. pH c. regulating enzyme activity by competitive inhibition d. regulating enzyme activity by non-competitive inhibition

TEMPERATURE: --Lowering temperature will lower enzyme activity, causing cells to grow slower --Warmer temperatures can increase enzyme activity --High temperatures can cause enzymes and other proteins to become denatured --------------------------------------------------------- pH: --H+ (acid) and OH- (base) affect hydrogen and ionic bonds --pH above or below optimal pH will alter enzyme structure by disrupting bonds --Extreme changes in pH can also lead to protein denaturation --------------------------------------------------------- Effects of competitive inhibition: --Slow reactions by competing with a substrate for the target enzyme's active site --------------------------------------------------------- Effects of noncompetitive inhibition: --Decrease enzyme activity by binding to the enzyme at a site other than the active site

Calculate generation time

The time it takes for a particular species of cell to divide. Bacterial generation times are diverse and can range from 15 mins to 24 hours or more depending on the species and growth conditions. growth time ------------------ # of generations

Describe the factors that would be important when evaluating measures of frequency. Describe the factors which would be important when evaluating measures of association.

Two main factors impact prevalence rate Incidence rate: number of new cases in a defined population during a defined time frame Duration: how long the infection lasts --------------------------------------------------------- Presenting data by ethnicity, age, or other host factors may identify public health interventions Organizing data based on the geographical location of cases could identify a shared factor linked to disease

Describe how a catalyst works. Give an example of a biological catalyst

a catalyst works by providing an alternate reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy. --an example of a biological catalyst is an enzyme. it accelerates a chemical reaction without altering its equilibrium

12. Please answer the following pertaining to the epidemiological triangle: a. list the three factors of the epidemiological triangle, b. give examples of host and environmental factors that form an epidemiological triangle, c. provide several examples of how the epidemiological triangle can be broken, d. when is knowing the host and environmental factors that lead to a disease more important than knowing the causative agent?

a. host, etiological agent, and environment b. host factors- general health, sex, lifestyle, age ethnicity, occupation environmental factors- climate, geographical location, water source,food source etiological agent- fungi, bacteria, virus, or parasite c. broken: Some basic public health strategies to target disease include: -Education -Quarantine -Vector control d. in some cases such as: --Many pathogens have a limited host range --Host factors can affect how a disease progresses (e.g., person's overall health, age, nutrition) --An infectious disease barely noticeable in a normally healthy host could kill an immunocompromised host --Preventing a disease is better than having to treat a disease

Distinguish between the types of bacteria and their oxygen needs

aerobes- microbes that have evolved to use oxygen in their metabolic pathways and usually have mechanisms to detoxify ROS so they can safely use oxygen in their metabolism --------------------------------------------------------- obligate aerobes—they have an absolute dependence on oxygen for cellular processes, and will die unless it is abundant --------------------------------------------------------- microaerophiles- use only small amounts of atmospheric oxygen and live in low-oxygen settings where they can limit their exposure to ROS while still meeting their oxygen needs --------------------------------------------------------- anaerobes- Organisms that do not use oxygen in their metabolic processes --------------------------------------------------------- aerotolerant anaerobes- they tolerate atmospheric oxygen, even though they do not use it in their metabolic processes. Like aerobes, these microbes have ways to deactivate ROS --------------------------------------------------------- obligate anaerobes- do not use oxygen in their metabolism and they tend to die in aerobic environments because they can't eliminate ROS --------------------------------------------------------- facultative anaerobes- spans both aerobic and anaerobic environments are; can use oxygen for their metabolism, but if needed they can perform anaerobic metabolism when oxygen is absent

Define the term healthcare-acquired infections (HAIs) and discuss how they may be prevented.

an infection that a patient develops while receiving care in a health care setting --------------------------------------------------------- Basic preventive measures include: --Hand washing --Consistent use of personal protective wear (gloves, masks, and gowns) --Environmental sanitization --Equipment sterilization --Limiting patient transport --Single patient equipment use --Patient isolation (as needed)

Compare and contrast chronic carriers and asymptomatic carriers.

chronic carrier- a patient in whom the pathogen can exist in a dormant or latent state and reactivate later; a chronic carrier patient may remain asymptomatic for long periods only to have symptoms reemerge from time to time; even when chronic carriers are asymptomatic they may still infect others --------------------------------------------------------- asymptomatic carrier- individuals who harbor certain pathogens for extended periods without experiencing symptoms

What product of glycolysis goes into the intermediate, then what goes into the citric acid cycle?

pyruvic acid from glycolysis goes into the intermediate step and then acetyl co-A goes into the citric acid cycle from the intermediate step.