BIOL 251 Unit 3 Exam (Based on Review Sheet)

What are contaminants?

Microbe(s) we don’t want in certain places - UNDESIRABLE MICROBES

What is decontamination?

Destroying/removing undesirable microbes

What is resistance?

Some kind of factor that allows a microbe to withstand our efforts to kill/inhibit it

What things might affect our ability to properly decontaminate something? (Resistant factors-theres 4)

• Time of exposure (Longer time = more effective)

• Cell characteristics (Endospores, capsules, mycolic acids, etc)

• Biofilms vs free-living (Matrix makes difficult)

• Genetic/metabolic activity (Log phase is susceptible/effective)

What is the difference between sterilization and sanitization?

• Sterilization is the total destruction of all microbes + spores

• Sanitization is the reduction of number of microbes (kills some/inhibits others)

How does heat and cold work to kill/stop microbes from growing? Which is better at destroying them?

• Heat causes most proteins in microbes to denature → inactivates them

• Cold slows metabolic function → slows growth (often does not kill microbes)

• Heat destroys them

How does ionizing radiation work to kill microbes?

• Destroys bonds

• Forms toxic substances that causes cell to die

How does non-ionizing radiation work to kill microbes?

• Interferes with protein production + DNA replication → Stops bacteria from functioning metabolically + inhibits replication

What is filtration?

Process of passing liquids/air through a membrane with small pores

What is the drawback to filtration?

Does not remove toxins

What are disinfictants?

Kill vegetative cells, but not spores. Used on NON living things

What are antiseptics?

Prevents invasion of sterile tissue. Used on LIVING tissue

What are sterilants?

Destroys all life, including spores. Used on NON living things

What are degermers?

Removes microbes/debris. Used on LIVING tissue.

What are preservatives?

Inhibit growth of microbes. Used on NON living things

Difference between Categories of Chemicals vs Common Classes of Chemicals?

Chemical categories focus on where they are used/what their purpose is. Chemical common classes focuses on chemical characteristics and how they dmg microbial cell.

How do halogens work to kill/dmg microbes? Ex?

Denature proteins, interfere with enzyme function and cofactors. Ex: Chlorine & Iodine -Disinfectant/Antiseptic

How do phenols work to kill/dmg microbes? Ex?

They disrupt cell walls/membranes, cause protein dmg, and inactivate enzymes. Ex: Phenol - Disinfectants

How do detergents/soaps work to kill/dmg microbes? Ex?

Dmg membranes, denature proteins and dehydrate cells. Ex: Isopropyl - Disinfectants/antispetics

How do detergents/soaps work to kill/dmg microbes? Ex?

They remove microbes and reduce microbial load. Ex: Soaps & Detergents - Degermers

How do heavy metals work to kill/dmg microbes? Ex?

They bind to proteins/enzymes to inactivate active sites/functional group. Ex: Silver - antiseptic

What is the difference between b/w antimicrobials and antibiotics?

Antimicrobials are chemicals that KILLS/inhibits growth of all kinds of microbes. Antibiotics specifically kill bacteria/bacterial infections.

What does a broad-spectrum drug do? Why/how it functions?

Kill a wide variety of bacteria. It does this by affecting common structures like ribosomes and DNA/RNA

What does a narrow-spectrum drug do? Why/how it functions?

Kills only one or a few types of bacteria. Does this by targeting a specific structure such as cell membranes/walls or flagella

What are b-lactation drugs? How do they kill bacteria?

It is a cell wall inhibitor and are in half of antibiotics. They prevent/dmg the peptidoglycan from linking together.

What are polymyxins? How do they kill bacteria?

It is a cell membrane inhibitor. Attaches to lipid membrane and pulls it apart.

What are fluroqionolones? How do they dmg bacteria?

They are DNA/RNA inhibitors. They bind enzymes in DNA replication to either stop growth or kill bacteria.

How do aminoglycosides, tetracyclines, chloramphenicol and macrolides work to kill bacteria?

Overall interferes with protein synthesis to inhibit it. They bind to ribosome and messes with mRNA reading, interferes with peptide bonds between amino acids.

How do sulfa drugs kill bacteria?

They stop metabolic pathways, specifically blocking folic acid synthesis, form functioning correctly.

How can bacteria be resistant to antibiotics? (5 things)

• Develop new/alternate enzymes (to break down drug)

• Inhibits uptake of drug (can’t come into cell)

• Develops drug transport pumps (pumps drug out)

• Alter binding sites (can’t bind)

• Change metabolic pathways (Develops different way to use cell properties to make necessary molecules)

How do resistant strains/colonies of bacteria develop?

Resistance exists NATURALLY through genetic sequences (evolve). Antibiotics do NOT CAUSE resistance.

How do antifungals dmg fungi?

They inhibit chitin synthesis and protein synthesis. Dmg structures like ergosterol.

How do antiprotozoals work to dmg Protozoa?

They get concentrated in parasite and inhibits cell processes/metabolism

How do antihelminthic drugs dmg helminths?

Inhibits microtubule function in worms and blocks glucose use

What is the general way all antivirals work to stop viral infections?

They block a stage in viral replication

What does normal flora mean? Where do we find it? What’s the difference between transient and residents?

Normal resident microbiota that live on and inside of us (Everywhere like our skin, parts of our systems). Transient flora are microbes that live with us for short periods of time (picked up during day-to-day activities) and resident flora are those that live with us for long periods of time (picked up shortly after birth)

What are the 3 main benefits of our normal flora?

• Protect/stabilize body surfaces

• Helps w/ development of immune system

• Helps with nutrient processing/production

What’s the difference between a sign and a symptom?

A sign is objective evidence (Things other people can see or measure like inflammation or RBC count). A symptom is subjective evidence (things the patient can feel like headaches and nausea)

What are the stages of infections? What happens in terms of # of microbes and intensity of signs and symptoms?

1. Incubation Period: Pathogen entry/adjustment. Microbes start to multiply slowly. No signs/symptoms

2. Prodormal: Generic signs/symptoms start to show

3. Illness: Experiencing classic signs/symptoms depending on illness (ex: coughing, headache, etc). # of microbes are @ highest

4. Decline: # of microbes drop and signs/symptoms begin to decrease too

5. Convalescence: Pathogen is cleared → final stages of healing

Graph looks like a triangle

What are the different types of carriers and their characteristics?

• Symptomatic carriers - Actively sick

• Asymptomatic carriers - People carrying the microbe, but no symptoms

→ Incubation period carriers - don’t know they’re sick yet

→ Convalescent carriers - Were sick, think they’r better

→ Chronic carriers - may never be obviously sick, but spreads it unknowingly

What are reservoirs and vectors?

Reservoirs are places in the world that microbes exist and vectors are typically diseases spread by insects or other arthropods (ex: malaria)

What is the basic difference between innate/non-specific immunity and acquired/specific immunity?

Innate works in response to ANY microbe for EACH exposure, while Acquired/specific is developed after FIRST exposure to SPECIFIC microbe

How do barriers work to keep microbes out of our body or keep us from getting infected?

By using chemical and physical barriers to destroy microbes or prevent them from living on us. Our skin is slightly acidic/salty, our tears/saliva destroy peptidoglycan, etc.

What are the different barriers?

• Chemical barriers - skin: Slightly salty/acidic

• Chem barriers- Lysozyme: Tears, saliva, etc. destroys peptidoglycan

• Chem barrier- Defensins: Found in skin to create holes in cell membrane

• Physical barriers- Skin

• Physical barrier- Cell shape

• Physical barrier- Lack of specific receptors

How/way inflammations works to harm microbes/help us?

It traps microbes/inhibits them and them mobilizes/attracts immune cells to the area.

What is a pyrogen? What are the benefits of fevers to us?

Pyrogens stimulate a rise in temp. It increases temp to speed up metabolism and slows microbial growth.

What is an interferon? How does it work to inhibits/stop viral infections?

Are proteins that have a purpose of signaling to body cells that there is a virus present and to not replicate it.

• Virus attachment alerts initial host cell to produce INFs → INFs attaches/enters other potential host cells to alert them → the others begin to produce proteins that stops spread of virus replication. (THE BRITISH ARE COMING!!)

How does the complement cascade work to kill microbes? (Not the steps)

It creates holed in microbial membrane

!!!! What are the different stages of the complement cascade? (There are 4)

1. Initiation: Body recognizes foreign microbe, protein production starts

2. Amplification: Many proteins made

3. Polymerization: Complementary proteins join

4. Membrane Attack: Joined proteins insert in membrane

What B&T cells do to help respond to antigens and produce antibodies?

B&T Cells are a type of lymphocytes. T cells respond after recognizing a foreign antigen in which activates the B cells to check it out and make the necessary corresponding antibody to combat it through plasma cells and circulating memory B cells.

What is an IgM?

A pentamer antibody that does agglutination. It’s the first antibody produced in response to a microbe

What is an antigen?

Substances that provoke immune response - our body recognizes these as foreign

What are the 5 main ways antibodies (Ig-immunoglobulins) work to destroy/disable microbes?

Attaches to pathogens or toxins and helps in inactivating them through:

• Neutralization: After binding, it prevents microbe from attaching (Effective against viruses)

• Precipitation: Sticks to toxins to make it not soluble

• Opsonization: Helps with phagocytic attachment

• Agglutination: Helps microbes stick together in one space, instead chase them everywhere

• Complement Activation/assistance: Activates membrane attack to make it more effective

What are the 5 different types of antibodies and what are the general characteristics/functions of each?

• IgA: Dimer (2 joined), Trap microbes, found in mucus membranes

• IgD: Monomer, found in small amounts attached to B cells

• IgE: Monomer, Active during allergic runs and worm infections

• IgG: Monomer, Provides long term immunity

• IgM: Pentamer, Does agglutination, 1st antibody produced in response to microbe

What is the difference between active and passive immunity and natural and artificial/acquired immunity? (The 4 types of adaptive immunity) What are some examples of combinations?

• Active: Exposure to ANTIGENS→ body makes antibodies = long term protection

• Passive: Exposure to ANTIBODIES → Injects body with premade antibodies = short term protection

• Natural: Developed thru human activities

• Artificial: Acquired thru medical interventions

Examples of combinations:

Natural active: getting a cut - Natural Passive: Breastfeeding infant (Antibodies produced from mom → passed to infant)

Artificial Active: Vaccines (Giving antigen, letting body make antibodies) - Artificial Passive: IV (Antibodies straight up given from lab)

What is the principle of vaccination (how/why it works to provide immunity)?

Exposure to antigenic, not pathogenic, part of microbe. After injection, it stimulates an immune response to develop IgG. It prevents illness from the actual microbe after being naturally exposed to it later on, since IgG is ready to act against it.

What are the 5 main types of vaccines in use today? How is each made and works as a vaccine?

1. Killed, whole microbe: Kills entire pathogen (so it can’t cause disease when injected in our body), but keeps antigen intact.

2. Live, attenuated: Entire live, but weakened microbe is used so it can’t grow in us.

3. Subunit: Microbe grown in lab, only parts of it are used

4. Toxoid: Toxin produced by microbe is used, inactivated in vaccine.

5. mRNA: mRNA sequence that codes for antigen is used. Our cells translates mRNA into protein to make antibodies. (Ex: COVID)

Why is the vaccination schedule set the way it is?

• Timing is based on developmental stage of child in relation to common exposure time, Immune response readiness and Decreasing maternal immunity (after 6 months its gone)