VBS 2032: EXAM 1

- What are some sources of phosphate and nitrate that contaminate freshwater? - Why does the addition of fertilizer stimulate algal growth?

- Fertilizer - Sewage - Landfills - Runoffs from manure Addition of fertilizer stimulate algal growth: - Nitrogen and phosphorus contribute to algae reproducing rapidly * 10-15-10 would stimulate algae growth 10: nitrogen 15: phosphate 10: potassium

- What properties of bacterial cell walls allow for discrimination by the Gram stain? - The Acid-fast stain? - What group of bacteria is considered "acid-fast"?

- For the gram stain, the peptidoglycan wall part is what makes the difference the gram (-) and gram (+) bacteria. Gram stain: dyes the peptidoglycan layer (if possible) - Gram (+): have a thick layer of peptidoglycan, so the dye can stain it - Gram (-): the outer layer in the gram (-) bacteria prevents the dye from getting to the peptidoglycan - Acid-fast stain: has a waxy coating on it to prevent it from drying out. - Acid fast bacteria would be mycobacteria. Mycobacteria: have a waxy coating that prevents entry of gram stains

Why don't most people get fungal lung infections?

- Fungus normally do not thrive in the human body - Those with a strong immune system are able to fight off fungal lung infections to which they wouldn't be infected. - immunocompromised people have a higher chance of getting a fungal infection

How does the Ghost pipe plant obtain food?

- Heterotrophic *pure white, no chlorophyll, does not photosynthesize - Acquires food because it's a parasite of a fungus which in turn gets its food from the roots of trees

- Why would an infection involving a biofilm be difficult to treat? - Why might the microorganisms be difficult to identify?

- Infection involving a biofilm can be difficult because it may be hard to detect the cause of the infection because some microbes cannot be cultured (so we cannot identify them, therefore, we don't know how to get ride of them) *many microbes in biofilms are resistant to antibiotic as they are not dividing.

- What are the structures of the prokaryotic cell? - What are the characteristics and functions of each?

- Lack membrane bound organelles - DNA concentrated in middle of cell in nucleoid - ribosomes involved in protein synthesis (composed of proteins and rRNA) 16s is important, - cytoplasmic membrane (semipermeable... phospholipids and membrane proteins)

In terms of temperature requirement, if you swabbed your refrigerator, what type of bacteria are you likely to find?

- Listeria monocytogenes is a psychrotroph that are cold-tolerant organisms that can grow at about 0-30°C. - These organisms are commonly associated with foodborne illness because they grow at room temperature as well as in refrigerated and frozen foods. - Listeria monocytogenes readily grow in refrigerated foods and can contaminate meat and fruit to cause food infections.

- What parts of the respiratory system contain the mucociliary escalator? - Explain how the mucociliary escalator helps remove particles from the respiratory tract. - What may happen when the mucociliary escalator is damaged by environmental toxins (like smoking) or viral infection?

- Mucociliary Escalator: comprised of cells in the trachea, bronchi and bronchioles - Ciliated cells: wave in a concerted motion to move the mucous and microbes up and out of the respiratory tract. - Goblet cells: produce mucous that traps fine particles including microbes. *The movements of the cilia push it and anything in it such as inhaled particles or microorganisms up and out the throat, which can either get swallowed or removed through the mouth. - Development of thick mucus - The mucus builds up allowing bacteria, fungi, and viruses to thrive causing lung damage and decreased oxygenation

- What kinds of bacteria lack cell walls? - What is an example of an obligate intracellular bacterium? (What does obligate intracellular mean?)

- Mycoplasma lack cell walls - Obligate intracellular: they cannot reproduce outside of their hosts and is reliant on intracellular resources EX of bacterium: rickettsia - causes spotted fever.

What are some surprising places microbes are found?

- Oceans - Vegetables - Inside of other living things - In extreme temperatures - At the bottom of the ocean - In the roots of plants (here they help fix nitrogen)

Why did some scientists have difficulty achieving the same result as Pasteur with the swan-necked flask?

- Pasteur used yeast and sugar broths which had no heat resistant microbes. - While the others used a hay based broth which had heat resistant organisms (endospores)

Why are pig whipworm eggs being considered for approval as a food ingredient in Germany?

- People in developing countries don't usually have allergies or asthma - Calms your immune system (the immune system is ATTACKING the body that it is meant to protect ex. allergies and asthma) -- worms calm down these cells, eat, and treat allergic conditions - In the past -- parasites were often and commonly found in the digestive system, and as hygiene has improved -- it is thought that the possible benefits of some parasites and their impact on the digestive tract were overlooked

- How do aquatic algae provide oxygen for aerobic organisms? - What happens when the algae die?

- Release oxygen during photosynthesis for the aerobic organisms to consume - The lack of oxygen produced makes it impossible for aquatic life to survive, thus creating dead zones. *May turn into algal blooms that can cause problems in drinking water and can release toxins that contaminate drinking water, causing illnesses

Why is salt a good preservative?

- Salt will lyse bacteria cells so they dry out and die (makes an environment that does not allow bacteria to thrive in), thus making it a good preservative *it causes plasmolysis due to the high osmosis potential created outside of the cell

How did scientists make the link between bacterial metabolism and TMAO accumulation?

- Scientists made the link by having people eat a steak and then taking their blood. - They found that vegans who didn't have certain bacteria in their gut did not make TMAO in their blood after eating steak, but meat eaters did.

Aerobic respiration = 38

- Sum of ATP produced in prokaryotic ___________.

Where are several places microbial biofilms can be found in daily life?

- Teeth (in plaque) - Showers - Slimy slipper rocks - Cathether

How do salt and sugar protect foods from microbial spoilage?

- They reduce water availability - By creating a hypertonic environment. The bacteria/fungi will not be able to reproduce, because the salt/sugar will take the water out of the organism.

- From a microbiome point of view, why might eating trehalose be bad for you? - How did the RT078 strain change so that cells could use trehalose? - How does this strain become more virulent when trehalose is present?

- Trehalose can provide a better food source for bad bacteria in the microbiome. - RT078 has extra genes that encode a transporter in the cell membrane that transports trehalose into the cytoplasm to be used for energy. - Caused one of strong bacterial strains to produce higher levels of toxin

- What are two forms of pathogenic protozoa? - Which one persists in the environment?

- Trophozoite: form that infects the body (do not survive in the environment) *Vegetative feeding form of some protozoa - Cyst: characterized by a thickened cell wall *very stable in the environment *Cysts can persist in the environment because it can resist treatment with chlorine or iodine

What two scientists helped explain the conflicting data?

- Tyndall: found some microbes have a heat resistant form - Cohn: discovered endospores

How does UV-C light kill microbes?

- UV-C rays penetrate through the walls of bacteria - Effective in destroying nucleic acids and breaking apart germ DNA which stops them from functioning or reproducing so the organism dies.

Gram stain

- Used to characterize some bacteria and yeast from the open-to-air plates. - is a differential stain used to separate bacteria into two major groups: * Gram-positive and Gram-negative. - The staining characteristics of these groups represent differences in the chemical structure of their cell walls. - This is the most widely used staining method for bacteria.

How can bacteria use carbon/energy sources other than glucose as starting molecules?

- photosynthesis - use ADP & NAD instead of glucose if not available

What parts of the cell can act as virulence factors?

- pili (fimbriae): cells to adhere to surfaces - flagella: motility - biofilm and capsules: attachment, protection from desiccation, host evasion - endospores

spongiform encephalopathy

- prion diseases, are a group of rare degenerative brain disorders characterized by tiny holes that give the brain a "spongy" appearance. - Degenerative disease due to prion protein

Type of fungal infections (mycoses)

- superficial and cutaneous (epidermis hair nails)-- Tenia pedis --> causes athlete's foot - subcutaneous (dermis, subcutaneous tissues)-- usually occurs after skin trauma - systemic-- originates in the lungs and may spread --> inhalation of Histoplasma capsulatum can cause disseminated histoplasmosis

What if O2 is not available?

Anaerobic respiration: - Alternate electron acceptor (eg. NO3) - Electron transport chain --> Proton Motive Force--> ATP Fermentation: - No ATP - In the absence of O2, some cells use pyruvate as a terminal electron acceptor

In the absence of oxygen, some bacteria can obtain some energy from glycolysis followed by: A. TCA Cycle B. Anaerobic respiration C. Aerobic respiration D. Pentose phosphate pathway

B. Anaerobic respiration - Does not use O2

Complete clearing on a blood agar plate is called ________ hemolysis A. Gamma B. Beta C. Alpha D. Clear

B. Beta

Isolate O1 is a(n): (look at picture) A. Obligate aerobe B. Obligate anaerobe C. Facultative anaerobe D. Aerotolerant anaerobe

B. Obligate anaerobe

Viroids are known to infect: A. All organisms B. Plants C. Viruses D. Animals

B. Plants

Nitrogen fixation is an essential process carried out by: A. plants B. algae and bacteria C. fungi D. protozoa

B. algae and bacteria

Compounds that temporarily inhibit bacterial growth are termed: A. bactericidal B. bacteriostatic C. antimicrobial D. disinfectants

B. bacteriostatic

A facultative anaerobe: A. grows best in absence of oxygen B. can grow in absence of oxygen but grows better in presence of oxygen C. can only grow at a low oxygen concentration D. can only grow in presence of oxygen

B. can grow in absence of oxygen but grows better in presence of oxygen

A spherical bacterium would be called a: A. bacillus B. coccus C. spirillum D. vibrio

B. coccus

Which of the following is a prokaryote? A. algae B. cyanobacteria C. protozoa D. microscopic invertebrates

B. cyanobacteria

Adding iodine during the Gram stain procedure: A. Stains cells purple B. Stains cells pink C. Acts as a mordant D. Removes crystal violet

C. Acts as a mordant

Algae and Protozoa share the following characteristics A. Both can be unicellular or multicellular B. Both have cell walls C. Both have nuclei D. In the body, both are trophozoites

C. Both have nuclei - They are both eukaryotes - Algae can be unicellular or multicellular BUT protozoa is unicellular and lack cell wall

The function of NADH and FADH2 in electron transport is to: A. Accept electrons B. Recruit protons C. Donate electrons D. NADH and FADH2 are not involved

C. Donate electrons

A common environmental organism that may even grow in certain chemical disinfectants is A. Escherichia coli. B. Streptococcus pneumoniae. C. Pseudomonas aeruginosa. D. enveloped virus.

C. Pseudomonas aeruginosa.

The idea of spontaneous generation postulated that: A. organisms could evolve into the next generation of organisms. B. organisms could spontaneously combust. C. organisms could spontaneously arise from other living organisms. D. living organisms could spontaneously arise from non-living material

D. living organisms could spontaneously arise from non-living material

In eukaryotic cells, energy is generated in this organelle: A. Golgi apparatus B. ribosome C. nucleus D. mitochondria

D. mitochondria

Could penicillin be used to treat a patient with pneumonia caused by Mycoplasma pneumoniae? Why or why not?

No because Mycoplasma do not have cell walls, therefore penicillin cannot be used to treat a patient. - Penicillin blocks the cell wall synthesis which won't help bacteria that do not have cell walls.

Is a virus considered a microorganism? Why or why not?

No because: - they are acellular (not composed of cells) infectious agent - nonliving (not alive) due to it having either DNA or RNA. - Can't reproduce independently

We do not yet know the extent of microbial diversity. Why not?

Some microbes live in places we can't get to. All microbes are microscopic, so isolating them in order to learn about them is difficult. The diversity is so significant that it is not feasible to find and study every single microbe. - not all microbes are able to be cultured because we don't have the right environment conditions for them *hard to recreate optimal growing environments in a lab. We do not know the growing requirements of some.

The majority of the hyphae of mold you see on food is below the surface. Are these the vegetative or aerial hyphae?

Vegetative hyphae - They penetrate the supporting medium and absorb nutrients while the aerial hyphae projects above the surface

Define: - Viridae - Nucleic acid - Capsid - Spikes - Virulent phage

Viridae: family names end in Nucleic acid: A macromolecule consisting of one or two nucleotide chains; DNA or RNA Capsid: protein coat surrounding the nucleic acid of a virus Spikes: (attachment proteins) structures on the outside of the virion that bind to host receptors Virulent phage: A phage that reproduces only by a lytic cycle. - Exit the host at the end of the infection cycle by lysing the cell (causing cell death)

- Can viroids infect humans? - Where do viroids cause significant disease?

Viroids can only infect plants but may infect us in ways we haven't discovered.

Microboes

- Evolved around 3.7 billion years ago

In terms of the human microbiome and metabolism, why is eating a fiber-rich diet good for you?

- A fiber rich diet is good for you because more fiber means more different types of bacteria in the gut. - Low fiber diet leads to less diverse gut and offspring could have even fewer microbes.

- What is the energy currency of the cell? - What general set of reactions produce it? - What type of reactions use it?

- Adenosine Triphosphate (ATP) is the energy currency of the cell - Glycolysis, Krebs, ETC - Anabolic reactions

How are autotrophs and heterotrophs different?

- Autotrophs: make their own food - Heterotrophs: obtain nutrition from ingesting another substance that provides nutrients.

How are true algae and cyanobacteria similar? How are they different?

- Both have chloroplast and use photosynthesis Differences: True algae: - Eukaryotic with nucleus - Unicellular or multicellular Cyanobacteria: - Prokaryotic

What are two enzymes that obligate aerobes and facultative anaerobes make that protect the cells from reaction oxygen species (ROS)?

- Catalase: enzyme that breaks down hydrogen peroxide (H2O2) to produce water and oxygen gas (O2) - Superoxide dismutase: enzyme that degrades superoxide to produce hydrogen peroxide

What are basic components of a cell membrane? Functions that membrane proteins serve?

- Composed of phospholipids (hydrophilic: the outside of the membrane interacts with water, hydrophobic: the inside does not). - Functions: provide a selectively permeable membrane, decides what can and cannot come in. - Membrane proteins: are used for structure, transport, communication, attachment, and sensing the environment which can help decide gene expression.

Why is the decolorization step in the Gram-Stain important?

- Decolorizing is the most critical step in the Gram stain procedure. If the cells are exposed to the alcohol/acetone for too long they will be over-decolorized: - Gram (+) cells will be pink If cells are under-decolorized: - Gram (-) cells will be blue. In order to stop the decolorization process: - Slides are rinsed with tap water immediately after dipping the slide in the decolorization (alcohol/acetone) solution.

Prootozoal cysts can be resistant to chlorine. Why is this significant?

- Disinfectants and/or other solutions containing chlorine may not be effective in killing these pathogens - This can be bad because protozal cysts can cause giardia in the water which is bad for immunocompromised people.

Why use pig whipworms instead of human whipworms?

- Does not colonize like a human, but you get the same benefit - Pig whipworms would not last as long in the human digestive system as human whipworms would --- therefore vastly decreasing the risk of infection from them!

- Which is more sensitive to chemical treatment, enveloped or non-enveloped (naked) viruses. Why? - Why are Mycobacteria more resistant than Gram + bacteria?

- Enveloped viruses are more sensitive to chemical treatment because their cell walls can be attacked by chemicals - Mycobacteria are more resistant due to their waxy coating that makes it harder to attach - Gram + bacteria are less resistant due to their cell wall that can be attacked.

What are three ways in which microbial activity is essential for life on this planet?

1. Oxygen creation: algae create more oxygen than trees 2. Nitrogen fixation: process where microbes take atmospheric nitrogen and reduce it to make ammonia - nitrogenous bases are part of the genetic code -- certain bacteria are responsible for fixing N2 into NH3 (ammonia) 3. Recycling: without fungi and other saprophytes (a plant, fungus, or microorganism that lives on dead or decaying organic matter) -- dead plant and animal matter would encase the planet *(microbes are essential for life as we know it)

What are two ways microbes have changed that impact healthcare?

1. Antibiotic resistant microbes 2. pathogenic (disease-causing) microbes

What are some ways that the Chain of Infection can be broken?

1. Isolate and treat the patient 2. Wash hands 3. Disinfect surfaces/ using proper PPE when handling infectious surfaces 4. Vaccinate

Can you explain how the swan-necked flask experiment helped disprove the idea of spontaneous generation?

1. Microbes were found in the air and due to their weight they would fall into the bent part of the swan-necked flask 2. The microbes did not come from an inanimate object but from the air itself

Steps of Gram Stain

1. Primary stain - crystal violet - is first applied to the smear *All bacteria are initially stained blue by the crystal violet 2. Mordant - Iodine is added to enhance the crystal violet stain by forming a crystal violet - iodine complex. 3. Decolorization - A mixture of alcohol and acetone are used - Bacterial cells with a thick peptidoglycan layer in their cell walls retain the crystal violet during this step *Gram (-): colorless *Gram (+): purple 4. Counterstain - Safranin: Stains the bacterial cells pink *Gram (-): pink *Gram (+): purple

The ocular lens magnifies objects 10X. If you view a slide using the 40X objective, what is the total magnification of the specimen?

40 x 10 = 400

What is a phylogenetic tree?

A tree of life based on DNA sequence

Fertilizer A is 10-12-10 and Fertilizer B is 10-0-15. If rain washes some of the fertilizer into a nearby lake, which one will likely stimulate the most algal growth? Why? A. A because it contains more phosphate. B. They will both have the same effect. C. B because it contains more potassium. D. A because it contains more nitrogen.

A. A because it contains more phosphate. - 0 in the middle: no phosphate (first number is nitrogen and last number is potassium) Nitrogen and phosphate contribute to algal growth

The bacteria in this Gram stain are: A. Gram-negative diplococci B. Gram-positive streptococci C. Gram-positive diplococci D. Gram-negative streptococci

A. Gram-negative diplococci - Gram (-) after the counterstain will turn pink - Streptococci is like a long chain

In our experiment, which antiseptic was most effective A. Hibiclens B. Bleach C. Iodine D. Bactine

A. Hibiclens (handwashing lab)

A research laboratory is investigating factors that would inhibit the growth of Archaea. One question they have is if adding the antibiotic penicillin would be effective in controlling growth. What do you think the outcome would be if they tried this? A. The penicillin wouldn't affect the Archaea because it prevents crosslinking of peptidoglycan-Archaea don't have this compound in their cell walls. B. The penicillin will inhibit cell wall formation in the Archaea, killing them. C. The penicillin will slow down the growth of the Archaea by damaging the cell wall, but they will still be able to grow somewhat. D. The penicillin will enhance the growth of the Archaea by providing a rich nutrientsource.

A. The penicillin wouldn't affect the Archaea because it prevents crosslinking of peptidoglycan-Archaea don't have this compound in their cell walls. - Archaea have a cell wall that does not contain peptidoglycan *Penicillin blocks the cell wall synthesis which won't help Archaea that do not have a cell wall of peptidoglycan

The theory of spontaneous generation postulated that: A. living organisms could arise from non-living material B. organisms could arise from other living organisms C. visible organisms originated as eggs D. organisms could reproduce asexually

A. living organisms could arise from non-living material

At the completion of the electron transport system, electrons originally present in glucose have been transferred to: A. oxygen B. carbon dioxide C. water D. NAD

A. oxygen

The process of killing or removing all of the microorganisms in or on a material is termed A. sterilization B. disinfection C. sanitation D. antiseptic

A. sterilization

Define: - Anabolism - Catabolism - Metabolism

Anabolism: Reactions that synthesize new molecules *Requires energy of ATP Catabolism: Reactions that break down molecules *Releases energy stored as ATP Metabolism: The sum of all the chemical reactions in the cell

- What is the difference between an acidophile and a neutrophile? - Which one would grow in a jar of pickles?

Acidophile: organisms that grow optimally at a pH below 5.5 -Would grow in a jar of pickles due to the acidity Neutrophile: organisms that can live and multiply within the range of pH 5-8 and have a pH optimum near neutral (pH7)

- What is the difference between an acute, chronic and latent viral infection? - Which one is most likely to spread when the host is asymptomatic?

Acute: burst of virions released but host may survive even though virus-infected cells die, immune system gradually eliminates virus Chronic: continuous production of low levels of viral particles, only small proportion of cells infected at any time, can still transmit virus even in absence of symptoms, most likely to spread when host is asymptomatic Latent: viral genome remains silent but can reactivate to cause infection

Scientists were unable to culture bacterium X from a soil sample even though DNA sequence data indicated that the bacterium was present. Why? A. Bacterium X can only grow in the presence of certain other bacterial species. B. Bacterium X has complex nutritional requirements. C. Lab techs placed the culture plates at the wrong temperature.

All are correct: A. Bacterium X can only grow in the presence of certain other bacterial species. B. Bacterium X has complex nutritional requirements. C. Lab techs placed the culture plates at the wrong temperature.

A suffix used to describe a killing action would be: A. -static B. -cidal C. -cillin D. -tion

B. -cidal Bactericidal: those that result in bacterial death - Describes a chemical or treatment that kills bacteria

Define: - Antimicrobial agents - Antimicrobial medication (chemotherapeutic agent) - Antiseptics - Use-dilution test

Antimicrobial agents: control the growth of microbes Antimicrobial medication (chemotherapeutic agent): Antimicrobial drugs taken internally are often grouped together by the term, "antibiotic", although the term but ____________ is more accurate Antiseptics: are used on living tissue Use-dilution test: Hospital grade disinfectants must pass the standard American Official Analytical Chemist's ___________

Define: - Antiseptic - Disinfectant - Sterilant or sterilization - Pasteurization - Bacteriostatic - Bactericidal - Preservation

Antiseptic: Used on skin or body tissues, they reduce the number of microbes. Disinfectant: a chemical substance that kills most or all harmful bacteria or viruses (are used on inanimate surfaces to reduce the level of microbes.) *Most or all pathogens are eliminated Sterilant or sterilization: completely removes or destroys all microbes (with one exception) Pasteurization: NOT sterile; reduces the level of pathogens and spoilage bacteria Bacteriostatic: bacterial growth is inhibited, but cells are not killed Bactericidal: those that result in bacterial death - Describes a chemical or treatment that kills bacteria Preservation: Maintenance of a resource in its present condition, with as little human impact as possible.

What two scientists are credited with discovering microorganisms?

Antony Van Leeuwenhoek: made the microscope Robert Hooke: published a book with detailed drawings of microoganisms

- How do viruses attach to cells? - Why are viruses usually specific for a single cell type and/or single host species? - Why are there relatively few antiviral drugs (as opposed to antibacterial drugs)?

Attach to cell via spikes. - Lipid membrane fuses with cell membrane. - Entire cell is injected with DNA/RNA, the protein capsid and nucleic acid enter the cell. - Capsid is removed and the nucleic acid is released. Viruses specific: - Virions must bind to specific receptors *most receptors are usually in a small number of cell types, so they can only infect certain species Few antiviral drugs: - Difficult to achieve selective toxicity because similar to human cells, viruses grow inside human cells & hard to understand how they replicate

How do bacteria move? How might this increase a pathogen's ability to cause disease?

Bacteria can move from: - flagella twitching using pili *pili can attach to each other and exchange DNA - gliding: extracellular polysaccharides is a kind of slime that is used to move - axial filaments (internal flagella that propels in the spire of heat through the media in a corkscrew motion that can penetrate cells). Will increase a pathogen's ability to cause disease because they can move into the host and are not stationary.

Can bacteria develop resistance to antibacterial chemicals like benzalkonium chloride?

Benzalkonium chloride is a (Quaternary Ammonium Compounds) QAC, with broad-spectrum antimicrobial activity. - Its vast use could lead to accumulation in the environment and selection of biocide resistant bacteria, which could be cross-resistant to antibiotics

What would the oxygen requirements be for a bacterium that lives deep within a biofilm? On the surface?

Biofilm deep: - Low oxygen for anaerobic metabolism Biofilm on the surface: - High oxygen for aerobic metabolism

- Compare and contrast difference types of heat treatments. - Which one(s) results in sterilization?

Boiling: not sterile; kills vegetative cells only Pasteurization: not sterile; reduces the level of pathogens and spoilage bacteria through heating Pressurized System: autoclaves or pressure cookers; uses steam which reaches higher temperatures Dry Heat: useful for objects that can't get wet; the ovens used in laboratories, takes a long time and not as effective as steam Incineration: how our loops are sterilized in lab Filtration of fluids: Using a filter sterilizing unit; pour the liquid into a cup, attach a vacuum and pull the liquid down *Sterilization: pressurized steam, dry heat ovens, incineration

A bacterial species was isolated from the middle of a compost pile where the temperature was 55-65°C. The group that best describes this microorganism would be: A. Hyperthermophile B. Mesophile C. Thermophile D. Psychrotroph

C. Thermophile Psychrophilic: microorganisms grow between -5C - 15C Psychrotrophic: microorganism grow between -2C - 35C Mesophilic: microorganisms, the most common type of microbe, can grow between 15C - 45C. Thermophilic: microorganisms require a temperature range between 45C - 80C Hyperthermophilic: microorganisms require a temperature range between 75C - 115C

A yeast infection should be treated with a ________ drug: A. antibacterial B. antiviral C. antifungal D. antiprotozoal

C. antifungal - Yeast is a type of fungus

An antiviral drug that binds to a viral spike protein would directly prevent: A. budding B. protein synthesis C. attachment D. host cell lysis

C. attachment

The scientific name of an organism includes its: A. family and genus. B. first name and last name. C. genus and species. D. genus and species AND domain.

C. genus and species.

An increase in the ___________will decrease the likelihood of infection. A. Number of microbes B. Virulence of microbes C. host immunity

C. host immunity

Define: - Cellular Respiration - Fermentation - Oxidative Phosphorylation - Photophosphorylation - Substrate-level Phosphorylation

Cellular Respiration: Metabolic process that transfers electrons stripped from a chemical energy source to an electron transport chain, generating a proton motive force that is then used to synthesize ATP Fermentation: Metabolic process that stops short of oxidizing glucose or other organic compounds completely, using an organic intermediate as a terminal electron acceptor - NO ATP - Electron acceptor: Pyruvate (or derivative) - Byproducts: lactic acid, ethanol, butyric acid, propionic acid, mixed acids, 2,3-Butanediol What fermentation byproduct can accumulate in muscles during intense anaerobic exercise? - Lactic acid Oxidative Phosphorylation: Synthesis of ATP using the energy of a proton motive force created by harvesting chemical energy - uses proton gradient to generate ATP from ADP - NADH oxidized to NAD+ yielding 2.5 ATP & FADH2 yields 1.5 ATP, - energy from proton motive force Photophosphorylation: Synthesis of ATP using the energy of a proton motive force created by harvesting radiant energy Substrate-level Phosphorylation: Synthesis of ATP using energy released in exergonic (energy-releasing) chemical reaction during breakdown of energy source - formation of ATP by direct transfer of PO3 group to ADP - energy from exergonic reactions

- What is a chemoorganoheterotroph? - A photoautotroph?

Chemoorganoheterotroph: obtains both energy and carbon form organic compounds - Energy source: Organic compounds (sugar, amino acids) - Carbon source: organic compounds 3 options: - Aerobic respiration (38 ATP) - Anaerobic respiration (varies, but less than) - Fermentation (2 ATP) Photoautotroph: organism that use light as energy source and CO2 as the major carbon source - Energy source: sunlight - Carbon source: CO2

What is "C. diff"? Why is it difficult to control in hospital setting?

Clostridium difficile "C. diff": is a bacterium that can cause Colitis *Due to it being an endospore, it is hard to control in a hospital setting because the endospores are resistant to heat, UV desiccation and toxic chemicals. - They are hard to kill and easy to spread

Where might copper be used in a hospital setting?

Copper is imbedded into surfaces that are often touched (door handles, etc.) - It reduces the amount of microbes that are transmitted in hospitals because it has antimicrobial characteristics

- What is EPS? What does it do? - What is an example of a way in which microbes can cooperate in a biofilm? - What is a way in which microbes can compete in a biofilm? - Why are microbes generally more resistant to antibiotics and disinfectants when growing in a biofilm?

EPS: Extracellular polymeric substance - Made of planktonics - Gooey substance, polysaccharide, or DNA, its protective for biofilms and cells can be cooperating or competing. Cooperating microbes in biofilm: - Communicate via chemical signals - Do separate jobs to coexist by doing specific things. - bioremediation efforts, which use microbes to degrade harmful chemicals Competing microbes in biofilm: - When multiple microbes need O2 to survive - They can produce antibiotics for each other and they can target each other by that. Microbes resistant to antibiotics and disinfectants: - Due to the biofilm acting as a protective layer, one can only get rid of it through mechanical scrubbing. - The antibiotic affected cells are protected by the resistant persister cells. *Persister cells lie in the dormant cells and antibiotic sensitive cells might be protected by antibiotic resistant cells. (makes them resistant to antibiotics) *Microbes protected by a biofilm are also unaffected by disinfection products.

Define: - Electron Transport Chain (ETC) - Proton Motive Force - Terminal Electron Acceptor

Electron Transport Chain (ETC): Group of membrane-embedded electron carriers that pass electrons from one to another, and, in the process, create a proton motive force Proton Motive Force: Form of energy generated as an electron transport chain moves protons across a membrane to create a chemiosmotic gradient Terminal Electron Acceptor: Chemical that is ultimately reduced as a consequence of fermentation or respiration

- How and when are endospores formed? - What two bacterial genera produce endospores? (Clostridium and _______?) - What are two forms of endospores? - Does boiling typically inactivate (kill) endospores?

Endospores: heat resistant forms of bacteria Formation: - The bacterium divides in the cell wall, and one side engulfs the other, creating a double membrane around the DNA. - Before the newly formed endospore is released, it is dehydrated and allowed to mature. - This occurs in gram-positive bacteria! - 2 bacterial genera: Bacillus and clostridium Endospores forms: - Vegetative spores (non-reproducing) and reproducing endospores - No, one needs to use a pressure-cooker to kill endospores because the are highly heat-resistant

- According to the Endosymbiotic Theory, what is the origin of mitochondria? - Of chloroplasts? (What takes place in the chloroplast?) - Which organelles came first: mitochondria or chloroplasts?

Endosymbiotic theory states that at some point a cell engulfed a bacteria and that bacteria stayed there and eventually became a mitochondria. - Double membrane and DNA sequence of their chromosomes similar to Rickettsia Chloroplasts: *The same thing is assumed to have occurred with chloroplasts. - The DNA sequence of chromosomes and double membrane in a chloroplast is similar to cyanobacteria - First endosymbiotic event occurred: The ancestral eukaryote consumed aerobic bacteria that evolved into mitochondria. - Second endosymbiotic event: the early eukaryote consumed photosynthetic bacteria that evolved into chloroplasts

- What is the difference between an enveloped and non-enveloped virus? - What is the envelope composed of and where do viruses obtain an envelope?

Enveloped: - Spikes (sticking out which allows viruses to adhere/bind to them.) - Matrix protein - Nucleocapsid (Nucleic acid and capsid (entire protein coat)) - Enveloped Non-enveloped: - Capsomere subunits - Nucleocapsid (Nucleic acid and capsid (entire protein coat)) - Spikes (sticking out which allows viruses to adhere/bind to them.) Viruses in enveloped: - The envelopes are typically derived from portions of the host cell membranes (phospholipids and proteins) *They may help viruses avoid the host immune system

- Enzyme definition - What are enzymes most commonly composed of? - Why are enzymes necessary? - Where does the substrate bind on an enzyme? How does the enzyme catalyze the chemical reaction? - What environmental factors influence enzyme activity?

Enzyme: A molecule, usually a protein, that functions as a catalyst, speeding up a biological reaction Composed of: Amino acids Why are enzyme's necessary? - They make the reactions occur quicker by lowering the activation energy - Substrate binds on the activation site of an enzyme - Enzyme cataylze the chemical reactions by lowering the activation energy Environmental factors influence enzyme activity: - Temperature - pH - Concentration of substrate *Enzymes can be used again

What are some basic differences between prokaryotic and eukaryotic cells?

Eukaryotic: - Unicellular or multicellular - Have membrane-bound nucleus where genetic material is located - Variety of membrane-bound organelles - Typically larger and more complex than prokaryotes - 3 groups: fungi, protozoa, algae Prokaryotic: - Single-celled organism (Unicellular) - Lack membrane-bound nucleus - Genetic material in located in nucleoid - 2 groups: Bacteria and archaea

True or False: Alcohol-based hand-sanitizers can inactivate endospores.

False, endospores are very hardy. Use soap and water to wash them away.

- How could you sterilize an antimicrobial drug solution for injection? - How could you sterilize a hospital mattress?

Filtration of fluids: - You would filter it because you cannot heat the drug solution because it will inactivate the antibiotic. Sterilize hospital bed: - You would use an aerosol type spray that would seep into the mattress and sterilize it - Using a disinfectant spray or bleach

- Does food need to be sterile? - Who is most at risk for food-borneillness? - What are the limitations of UV radiation for use in sterilization?

Food sterile?: - No because we can't completely sterilize it and there are many bacteria in our digestive system. Risk of food-borneillness: - Those who are immunocompromised, young children, older adults, pregnant women Limitations of UV radiation: - Damages DNA, penetrates poorly; used to destroy microbes in the air and drinking water, disinfects surfaces - Can be damaging to what you are sterilizing, causes cancer - Doesn't penetrate very far in depth

- If you completed a Gram stain, but forgot to add safranin, what color would Gram - cells be? How about Gram +? - If you forgot to do the decolorizer step, what color would Gram - cells be? How about Gram +? - What Gram + structure retains the crystal violet-iodine complex?

Forgot to add safranin: - Gram (-): non-visible - Gram (+): purple Forgot decolorizer: - Both Gram - and Gram + would be blue. - Bacteria *The peptidoglycan thick layer

What does the term "ubiquity" mean?

Found everywhere - microbiology meaning: MICROBES can be found everywhere and are a part of most (if not all) life forms on earth -- normal microbiota on hands -- enteric bacteria that break down nutrients

What does the term "planktonic" mean?

Free floating motile organisms in a body of water, primarily comprising microscopic algae and protozoa. (free swimming bacteria)

- What does the term "generation time" mean? - How can the total number of cells in a population be calculated if the generation time is known? (What is the formula and can you use it?)

Generate time: the time it takes for the bacterial population to double

How are microorganisms named?

Genus; first part of name, typically named after person who discovered bacteria, capitalized Species; 2nd part of name, named after where bacteria would be found in body, lower case Genus + Species EX: E coli.

What is the function of each of the pathways below? What is the input and yield of each? o Glycolysis o Transition Step o TCA cycle o Cellular respiration

Glycolysis: break down glucose, provide energy to cells; converts glucose to pyruvate - Input: Glucose (6C --> 2,3C), 2 ATP - Yield: 2 pyruvate, Net 2ATP, 2NADH + H+, 6 precursor metabolites Process: Glycolysis --> in (Glucose) out (pyruvate), produces ATP and precursor molecules Transition step: Highest potential energy along reaction coordinate, form Acetyl Co-A; links to TCA cycle, occurs in mitochondria in eukaryotes - Pyruvate uses 3-carbons to produce CO2 and 2 carbons and Acetyl CoA groups - Input: 2 pyruvate (2,3 C molecules --> 2, 2C + CO2) - Yield: 2 NADH + H+ and 2 acetyl-CoA, 1 precursor molecule Process: Transition Step --> in (pyruvate), out (Acetyl-CoA), move from glycolysis to TCA TCA cycle: aka Krebs cycle & citric acid cycle, finishes sugar-breaking & fuels production of ATP; oxidizes acetyl-CoA releasing CO2 - Input: 2 acetyl CoA (2, 2C molecule --> 4CO2) - Yield: 2 ATP, 6 NADH + 6H+, 2 FADH2, 2 precursor metabolites Process: TCA cycle --> in (Acetyl-CoA), out(citrate and NADH and ATP) Cellular Respiration: cells in plants & animals break down sugar & turn it into energy, provides cells w/ energy needed to function - oxidative phosphorylation uses reducing power from previous steps. electron transport chain pumps protons out membrane then uses proton motive force in ATP synthase to yield up to 34 ATP Process: Cellular respiration --> substrate level --> in(precursor), out (ATP)oxidative --> in (NADH), out (water and ATP)

- What are the basic differences between Gram-positive and Gram-negative bacteria? - Which group of bacteria is likely to be most resistant to disinfectants and antibiotics? Why? - What is the medical significance of LPS?

Gram positive: have a thick peptidoglycan layer and stains purple Gram-negative: cytoplasmic membrane of thin peptidoglycan layer and second cell membrane which is the outer membrane *Stains pink - TOUGHER and HARDER to kill and will be more resistant to disinfectant and antibiotics due to their extra outer membrane *MYCOBACTERIA is the most resistant to ENVIRONMENT! Mycobacteria: have a waxy coating which makes things harder to attach - LPS: Allows different molecules to pass through. *They span the whole cell. - Medical significance of LPS: protects the membrane from certain chemical attacks. *Protects the cell from invading molecules.

Define: - Gram-positive cells - Gram-negative cells - lyophilized

Gram-positive cells: bacteria appear blue when viewed with the microscope Gram-negative cells: lose the crystal violet during the decolorization step because their cell walls contain little peptidoglycan - cells are then visualized by the counterstain, Safranin, which stains them pink. lyophilized: freeze-dried

- What are the phases of the growth curve? - What is happening during each phase? - How might bacterial growth in pure culture be different than growth in a natural setting?

Growth curve phases: - Lag phase: no increase in cell number, cells begin synthesizing enzymes required for growth - Exponential phase: cell divide at a constant rate, generation time is measured during this period of active multiplication - Stationary phase: when the nutrient levels are too low to sustain growth, stage in which the number of viable cells remains constant - Death phase: period when the total number of viable cells in the population decreases as cells die off at a constant rate -Phase of prolonged decline: most cells die during this phase, but a few are able to grow

- What is the human "phageome"? - How is this distinct from the virome?

Healthy human gut phageome: presence of bacteria in gut to help w/ normal functions, healthy for individual - Phages that infect bacterial cells = "phageome" Virome: collection of viruses in & on human body *Healthy human gut generally help, virome generally hurt

What are the relative sizes of a human cell, a protein, a virus and most bacteria?

Human cell: 10-100 um Bacteria: 1-10 um Virus: 50-100 nm Protein: 5-10 nm *Human cell > Bacteria > Virus > Protein

- What is the "Hygiene Hypothesis"? - How might dogs (and other animals) positively impact our health?

Hygiene Hypothesis: lack of exposure to microbes can lead to allergies & autoimmune diseases - spending over 90 percent of our time in the bacteria-poor environment indoors, as we do (especially early in life, when our immune systems are being formed), can cause our bodies to overreact to harmless substances later on, making us sick. Or have allergies or asthma - lack of exposure to pathogens can lead to higher susceptibility - Dogs can bring in 56 different bacteria classes into the home from outside that otherwise wouldn't of entered *The "outside" microbes can help us grow our immune systems

From MMWR: How could the potato salad have been prepared safely? (Why did people become ill?).

If the potato salad was used with canned potatoes using the pressure cooker method, the high temperature (over 100F) would have killed the endospores (C. botulinum spores). - People got ill because the person who made the potato salad boiled the canned potatoes which did not kill the endospores, therefore, the endospores were still present on the potatoes leading to people getting ill.

What is the "indoor microbiome?"

Microbiomes that exist indoors where we live and spend most of our time. - The billions of bacteria, viruses, and fungi that we share our homes and offices with.

What is an example of a human disease caused by reactivation of a latent virus?

Latent virus: infection in which infectious agent is present but not causing symptoms Botulism (Clostridium botulinum), scarlet fever (streptococcus pyogenes), hemolytic uremic syndrome (E. coli).

- When a bacterium is in a state of lysogenic conversion, why does it express a different protein(s)---often a toxin? - What does this mean for the pathogenicity of the bacterium?

Lysogenic conversion: is when a phage is in a latent state (where no viral particles are being made, but DNA is in each replication of the host cell). *change in properties of bacterium conferred by prophage, phenotype is changed that is caused by viruses that are bad, if toxin encoded exclusively by phage genes then only bacterial strains that carry the prophage will synthesize the toxin - Bacterial populations can become more or less pathogenic, and the viruses are the ones that move the genes around.

What is the difference between lytic and temperate phages?

Lytic: a virus that infects bacteria and kills the cell Phages: 1. start with one and they attach to cell 2. Genome injected into host cell 3. Viral DNA is replicated, transcribed, and translated to make viral proteins 4. Host cell hijacked into making new viral particles in self-assembly 5. Host cell bursts or lyses because it's full of viral particles causing host cell death and the virus particles are dispersed and can go infect other cells. 6. CELL DEATH Temperate: restraint or self-controlled, doesn't go wild and kill all the cells all the time Phages: 1. Attachment 2. Injection of genome into host cell 3. CHOICE: can follow lytic path and go straight to host cell death (go to step 8) OR 4. follow latent state (no viral particles being made, but DNA is in each replication of the host cell 5. Viral genome integrated into host cell 6. Cell changed and replicates 7. stress is placed on cell and the viral DNA is transcribed 8. Lytic cycle continues as the host cell begins producing viral particles

Define: - MSA (Mannitol Salt Agar) - MacConkey - microbiota - fastidious - hemolysis patterns - hemolysin - β-hemolysis (beta) - α- hemolysis (alpha) - y-hemolysis (gamma) - heat-fixed - Simple staining - colony morphologies (shapes)

MSA (Mannitol Salt Agar): Selective: for Staphylococcus (Gram positive) - high concentration of salt Differential: by having a pH indicator to differentiate between Staphylococcus that can ferment sugar mannitol (EX: Staphylococcus aureus) and those that cannot *Selective (staph) and differential (mannitol) medium MacConkey: selective for bile salts and crystal violet in gram (-) bacteria and differential for lactose and pH indicator medium - _______ agar is also differential in that it contains lactose and a pH indicator that allows one to distinguish between bacteria that can digest lactose and those that can't digest lactose. microbiota: Microbes associated with the human body fastidious: Organisms that grow only when special nutrients are present hemolysis patterns: are created when microbes produce proteins like hemolysin that lyse red blood cells. hemolysin: lyse red blood cells β-hemolysis (beta): is the complete destruction of RBC's and hemoglobin resulting in a clearing around the colony on a blood agar plate. α- hemolysis (alpha): Partial destruction of RBC's and hemoglobin - produces a greenish discoloration of the blood agar surrounding the colony y-hemolysis (gamma): there is no destruction of RBC's and hemoglobin, so there is no change in the medium. heat-fixed: kills the bacteria, makes them adhere to the slide, and coagulates cytoplasmic proteins to make them more visible Simple staining: single dye used to stain a cell colony morphologies (shapes): method that scientists use to describe the characteristics of an individual colony of bacteria growing on agar in a Petri dish

Most microbes are not harmful. What are some reasons for this?

Most have characteristics that are different to ours, some can benefit human hosts, some don't have the same virulence factors. - Others are not parasitic at all, so they have no need to be infectious. - Many have a symbiotic relationship with other animals, in which case killing the symbiont would be selected against through evolution.

Hand soaps with effective antibacterial chemicals like chlorhexidine (Hibiclens) typically inactivate more microbes than ordinary hand soap. Should we use soaps like Hibiclens in our daily lives? Why or why not?

NO: 1. Bacteria can develop resistance to the antimicrobial chemical in Hibiclens 2. Hibiclens kills both harmful bacteria and our normal skin microbiota, which helps keep our skin healthy.

- What ATP generating options would an obligate aerobe have? - A facultative anaerobe? - An obligate fermenter? - An obligate anaerobe?

Obligate aerobe: Glycolysis, TCA cycle, aerobic respiration (oxidative phosphorylation) - grows only in O2 - Cellular respiration, glycolysis Facultative anaerobe: Capable of doing both aerobic or anaerobic / ferment. If O2 is not present the growth rate will be slower due to the fact that less ATP is produced - Grow best in O2 - Can deal with no O2 - Prefers cellular respiration but can do fermentation Obligate fermenter: fermentation Obligate anaerobe: Glycolysis, fermentation, anaerobic respiration *can do either glycolysis and fermentation, glycolysis and anaerobic respiration, or both all three pathways depending on the organism - grows in NO O2 - Fermentation - Anaerobic respiration

Define: - Obligate aerobes - Facultative anaerobes - Obligate anaerobes - Microaerophiles - Aerotolerant

Obligate aerobes: require O2 for growth, using it during aerobic respiration. Facultative anaerobes: use aerobic respiration when O2 is present but can switch to fermentation or anaerobic respiration when O2 is absent. Growth is typically much better in the presence of O2. Obligate anaerobes: use fermentation or anaerobic respiration. These organisms cannot grow in the presence of O2. Microaerophiles: grow best in conditions of increased CO2 concentration (5-10%) and low O2. Aerotolerant: anaerobes are obligate fermenters that do not use O2 but are not harmed by it.

- How is milk typically Pasteurized? - How does the fat in ice cream affect the conditions for Pasteurization of ice cream? - Why does Pasteurized milk eventually spoil in your refrigerator?

Pasteurized milk process: - Milk is typically pasteurized by heating it to 72C for 15 minutes then cooling it down. Fat in ice cream affecting Pasteurization: - Since there is so much fat in ice cream it needs to be heated to 82C for 20 seconds. *The conditions used to pasteurize ice cream mix are greater than those used for fluid milk because of increased viscosity from the higher fat content. Pasteurized milk spoiling, WHY?: - Pasteurization does not sterilize the milk, it only reduces the level of pathogens and spoilage bacteria, it doesn't kill them. *The bacterial not killed can still multiply and cause the milk to spoil

- How are pickles made? - What factors promote the growth of lactic acid bacteria? - What inhibits the growth of spoilage bacteria? - Where do the "good" lactic acid bacteria come from?

Pickle process: - cucumbers, salt and water in a jar *No oxygen and perfect temperature. Factors that promote lactic acid bacteria: - No oxygen and perfect temperature and salt What inhibits bacteria spoilage: - Salt "Good" lactic acid bacteria: - Come from the combination of factors in the pickling process.

Define: - Porin - LPS (lipopolysaccharide) - Mycobacteria - Mycoplasma - Rickettsia - Acellular Infectious Agents - Microorganisms - eutrophication - chitin - Autotrophic (photosynthetic) - heterotrophs - Yeasts - Molds - Mushrooms - Mycoses

Porin: Proteins in the outer membrane of Gram-negative bacteria that form channels through which small molecules can pass *special channel for certain proteins. LPS (lipopolysaccharide): Molecules that makes up the outer layer of the outer membrane of Gram-negative bacteria *Allowing different molecules to pass through. Mycobacteria: have a waxy coating that prevents entry of gram stains Mycoplasma: lack cell walls Rickettsia: a small bacterium that lives in lice, fleas, ticks, and mites - Gram-negative, nonspore-forming, highly pleomorphic bacteria that may occur in the forms of cocci, bacilli, or threads. Acellular Infectious Agents: not composed of cells - virus, viroid, prion Microorganisms: Organisms too small to be seen with the naked eye - prokaryotes (bacteria, archaea) - eukaryotes (fungi, protozoa, algae) eutrophication: when a body of water becomes overly enriched with minerals and nutrients which induce excessive growth of algae. (algae bloom that can release toxins) *This process may result in oxygen depletion of the water body that can lead to dense growth of plate life (algae bloom) and death of animal life from lack of oxygen. chitin: carbohydrate polymer that adds rigidity and structural support to the thin walls of fungi Autotrophic (photosynthetic): organism that can make their own food through the process of photosynthesis heterotrophs: Organisms that obtains carbon from an organic compound such as glucose Saprophytes: a plant, fungus, or microorganism that lives on dead or decaying organic matter. Yeasts: are single-celled fungi that produce smaller, smooth colonies on PDA plates Molds: are multicellular filamentous fungi that produce "fuzzy" colonies on the plates. Mushrooms: are simply the reproductive structures of certain fungi Mycoses: a diseases caused by infection with a fungus, such as ringworm or thrush

What are precursor metabolites used for?

Precursor metabolites: Metabolic intermediates that can be either used to make the subunits of macromolecules or oxidized to generate ATP - Used to synthesize new molecules in anabolism

Is there a cure for prion disease?

Prions: infectious protein molecule. - no cure, usually slow deaths

- What is a ribosome composed of? Function? - How are bacterial and eukaryotic ribosomes different? (What is the function of a ribosome?)

Proteins and rRNA - Non-membranous organelles found in both prokaryotes and eukaryotes cytoplasm that function to make protein (protein synthesis) - They are complex with a large subunit which joins amino acids to form a polypeptide chain and a small subunit which reads the RNA. - Prokaryotes have a 70s ribosomes (30s and 50s subunits) - Eukaryotes have a 80s ribosomes (60s and 40s subunits)

Define: - Protozoa - Algae - Cyanobacteria - photosynthesis - Microscopic invertebrates

Protozoa: are unicellular, heterotrophic eukaryotes that lack a cell wall and require moisture. - All are motile and classifed based on their mechanism of motility (pseudopod, cilia or flagella). - are predators of smaller microorganisms (bacteria, algae and some fungi) and can be enriched for by providing nutrition that encourages the growth of their prey. Algae: photosynthetic eukaryotes that are characterized by membrane-bound chloroplasts and the absence of true roots, stems or leaves. - Unicellular or multicellular Cyanobacteria: are prokaryotic cells that contain chlorophyll and use photosynthesis to convert CO2 to sugars photosynthesis: Conversion of light energy from the sun into chemical energy. *Reactions used to harvest energy of light to synthesize ATP, which is then used to power carbon fixation Microscopic invertebrates: Organisms without a backbone or bony skeleton that can only be seen via microscope

- What is reducing power? - What are two molecules used as reducing power in metabolic pathways?

Reducing power: is a reduced electron carrier that can donate electrons to another chemical that has a higher affinity for electrons - NADH, NADPH, and FADH2, their bonds contain a form of energy that can be used by a cell

Why does the research described in "An Irresistible Newcomer" represent a breakthrough discovery?

Scientists may have uncovered an antibiotic that targets lipid molecules, making the development of resistance difficult.

Define: - Spore - Hyphae - mycelium - vegetative hyphae - aerial hyphae - Sporangium - conidiophores

Spore: Molds reproduce through the production of _______. Hyphae: (singular "hypha") - Filament and the high branched mycelium: tangled mass of hyphae vegetative hyphae: Hyphae that absorb nutrition from the medium or environment aerial hyphae: Molds are often characterized by the type of spore-bearing structures found at the tips of the __________. Sporangium: Spores of some species of fungi form within a sack conidiophores: spores of some other types of fungi are produced externally in short chains at the tips of their aerial hyphae

Describe the structure of the SARS-CoV-2 virus. In basic terms, how does it replicate?

Structure: - Enveloped - Spike - Nucleocapsid - Matrix protein Replication: - Spikes attach to the viral surface and binds envelop to host cells. - Binds to the receptor of host cell and mediates virus fusion in transmitting host cells

- What is the difference between TSA and PDA plates? What types of microorganisms prefer growth on PDA? - Why?

TSA (Tryptic Soy Agar): Media is a general growth (supportive) medium containing a digest of soybean meal and casein (a protein found in milk), making it suitable for the growth of a wide range of microorganisms - Doesn't inhibit growth of bacteria Prefers: bacteria and mold. PDA (Potato Dextrose Agar): Is a general-purpose media for the isolation of yeast and molds as it supports the robust growth of fungus, which can metabolize the complex carbohydrate potato starch and tolerate low pH levels. Prefers: fungi (yeasts and mold) over bacteria because fungi can digest and utilize the complex potato carbohydrates as carbon source - PDA plates also have a lower pH.

Your friend recently ate a salad containing a brand of spinach that was recalled for contamination with E. coli. Can you explain to her the factors that will influence whether or not she becomes ill?

The number of microbes, virulence of microbes, and the host immunity (strength of immune system) (something that may be very dangerous to someone else may not be dangerous to you) are three factors that will influence whether or not she becomes ill. *(number of microbes x virulence of microbe) / host immunity

37oC

The optimum temperature for many human pathogens

differential stain

Used to distinguish one group of bacteria from another by taking advantage of the fact that certain bacteria have distinctly different components. EX: Gram stain or Acid-fast stain

Define: - Transient - Resident - Amphipathic

Transient: microbes are usually acquired from the environment and typically stay on the skin for a short period of time. - number of transient microbes can be reduced considerable by hand washing. Resident: microbes, also called microbiota, are associated with sweat and sebaceous glands. - These are not easily removed with soap and water. - Even after extensive hand washing, microorganisms that remain will grow and reestablish the microbial community. Amphipathic: Soap molecules are this, meaning that one end of the molecule is hydrophilic (water-loving) and the other is hydrophobic (water-hating). *The hydrophobic regions of soap insert into lipid membranes, disrupting the structure of enveloped viruses and some bacteria. *The hydrophilic tails interact with water, which washes the microbes away. In the same way, soap also disrupts bonding between microbes and skin.

Why was there only one fatality from the potato salad?

Typically if its ingested, its fatal. *Due to the early recognition of the outbreak and rapid response of the healthcare professionals there was only 1 fatality because others were caught in time.

Why should you re-cork you wine after you open it?

When making wine, one needs to remove air because acetobacteria is in the wine. Acetobacteria: can't grow in anaerobic conditions (it needs air), but can grow quickly with air. - Is an obligate aerobe that turns ethanol to acetic acid if O2 is present Re-corking of wine: prevents acetobacteria (an obligate aerobe that turns ethanol to acetic acid) from creating acetic acid in the wine and decreases change of lost flavor

- Can cellular respiration be anaerobic? - What type of molecule would be the final electron acceptor?

Yes, can be anaerobic through the substrate-level phosphorylation. *The final electron acceptor is nitrate.

Define: - dimophism ("dimorphic fungi") - Flagella - Cilia - Pseudopod

dimophism ("dimorphic fungi"): Fungi that are able to assume two forms, as the yeast and mold forms of pathogenic fungi Flagella: A long, whip-like filament that helps in cell motility. Cilia: Short, projecting hair-like structure of locomotion in some eukaryotic cells, similar in function to a flagellum Pseudopod: Transient arm-like extensions formed by phagocytes and protozoa - They surround and enclose extracellular material, including bacteria, during the process of phagocytosis

Define: - aseptic technique - Solid media - Agar - Liquid media ("broth") - Selective media - Differential media - Supportive medium

aseptic technique: involves the use of sterile media, containers, instruments and maintaining a clean work environment. - in the laboratory it is essential to prevent the contamination of your experimental culture as well as to protect yourself from exposure to a potential pathogen Solid media: Provides a firm surface upon which cells can form discrete colonies -Used to isolate bacteria and fungi *(agar) Agar: a gel-like polysaccharide compound used for culturing microbes; extracted from certain algae Liquid media ("broth"): a water-based solution that contains nutrients and does not solidify Selective media: Are used clinically to isolate and identify many types of medically important bacteria and in the analysis of food and water - contains additives that allow the growth of only certain types of microorganisms and inhibits the growth of other types. Differential media: are used to distinguish different types of microorganisms by altering the appearance of different colonies on the media based on their properties (such as the ability to ferment the sugar mannitol) Supportive medium: Culture media that are able to sustain the growth of many different kinds of microorganisms.

How can microbes travel?

flagella, cilia, gliding, fimbrae, slime coats, and magnetic forces

Virulence factor:

something that makes a microbe (bacteria, fungi, virus, protozoa) more potent to the host in attempt of infection *Something that makes you sick

What is "dwell time" with respect to disinfectants?

the amount of time needed to leave the disinfectant in contact with the surface before wiping it off