Microorganisms, Cell Structures, and Microbial Techniques: A Comprehensive Biology Review

What is a microorganism?

:A microscopic living organism

What are the major groups of microorganisms?

:Bacteria, archaea, fungi, protozoa, algae, viruses

What are the three domains of life?

:Bacteria, Archaea, Eukarya

Which domains contain microorganisms?

:All three domains

How do you write binomial nomenclature?

:Genus capitalized, species lowercase, italicized

Example of binomial nomenclature?

:Escherichia coli

How does a microscope work?

:Uses lenses to magnify objects

What microbes cannot be seen with a light microscope?

:Viruses

What is the Germ Theory of Disease?

:Microorganisms cause disease

Who proved Germ Theory?

:Louis Pasteur

How do cellular stains work?

:Bind to cellular structures to increase contrast

Why stain microbes?

:They are too small and transparent to see clearly

Difference between prokaryotic and eukaryotic cells?

:Prokaryotes lack nucleus and membrane-bound organelles

Required microbial structures?

:Cell membrane, cytoplasm, ribosomes, DNA

Optional microbial structures?

:Capsule, flagella, pili, spores

What is the microbial cell wall made of?

:Peptidoglycan in bacteria

Gram positive cell wall?

:Thick peptidoglycan layer

Gram negative cell wall?

:Thin peptidoglycan plus outer membrane

Possible energy sources for microbes?

:Chemical or light energy

Possible carbon sources for microbes?

:Organic or inorganic carbon

Factors influencing bacterial growth?

:Temperature, pH, oxygen, nutrients

What is a virus?

:An acellular infectious agent

Basic parts of a virus?

:Capsid, nucleic acid, sometimes envelope

What is needed to grow a virus?

:A living host cell

Difference between animal virus and bacteriophage?

:Animal viruses infect eukaryotic cells, bacteriophages infect bacteria

Difference between plant viruses?

:Enter through wounds or vectors

Steps of lytic cycle?

:Attachment, penetration, biosynthesis, assembly, release

Steps of lysogenic cycle?

:Attachment, integration, replication, induction

What is metabolism?

:All chemical reactions in a cell

What is catabolism?

:Breakdown of molecules to release energy

What is anabolism?

:Building molecules using energy

What is ATP?

:The main energy currency of the cell

Why do cells need ATP?

:To power cellular processes

Where is ATP energy stored?

:In phosphate bonds

Purpose of aerobic respiration?

:To generate large amounts of ATP

What happens in aerobic respiration?

:Complete oxidation of glucose using oxygen

Difference between aerobic and anaerobic respiration?

:Aerobic uses oxygen, anaerobic uses other electron acceptors

How is fermentation different?

:No electron transport chain, low ATP yield

What does an enzyme do?

:Lowers activation energy

What are enzymes made of?

:Proteins

Why are enzymes important?

:They make metabolism efficient

What are anaerobic chemoorganotrophs?

:Use organic compounds without oxygen

Difference between sterilization and disinfection?

:Sterilization removes all life, disinfection removes pathogens

What factors affect microbial control?

:Microbe type, environment, material

What is pasteurization?

:Heat treatment to reduce microbes

Is pasteurization sterilization?

:No

What are the hardest microbes to kill?

:Endospores and mycobacteria

Why are they hard to kill?

:Protective structures

How do antimicrobial drugs target microbes?

:By attacking unique microbial structures

Best drug targets?

:Cell wall and ribosomes

What is antimicrobial resistance?

:Ability to survive antimicrobial drugs

Five resistance mechanisms?

:Enzyme destruction, altered targets, efflux pumps, reduced uptake, alternative pathways

Why is the first line of defense important?

:Prevents pathogen entry

Four components of second line of defense?

:Phagocytosis, inflammation, complement, interferons

What are B cells?

:Adaptive immune cells that make antibodies

Where do B cells develop?

:Bone marrow

What do B cells become?

:Plasma cells and memory B cells

What do Helper T cells do?

:Activate other immune cells

How are Helper T cells activated?

:Antigen presentation on MHC II

Why are Helper T cells important?

:They coordinate immunity

What do Cytotoxic T cells do?

:Kill infected cells

How are Cytotoxic T cells activated?

:Antigen presentation on MHC I

Why are Cytotoxic T cells important?

:They remove infected cells

How do microbes interact with the host?

:Colonization, infection, disease

How do microbes evade immunity?

:Antigen variation, hiding, immune suppression

Difference between infection and disease?

:Infection is presence, disease is damage

What must happen for infection?

:Entry and colonization

What are normal flora?

:Microbes normally living in the body

Why are normal flora important?

:Prevent pathogen overgrowth

How do antibiotics affect normal flora?

:They disrupt balance

What are the four hypersensitivities?

:Type I, II, III, IV

Type I hypersensitivity?

:IgE mediated allergy

Type II hypersensitivity?

:Antibody mediated cell damage

Type III hypersensitivity?

:Immune complex deposition

Type IV hypersensitivity?

:T-cell mediated delayed response

What is a vaccine?

:Antigen preparation that stimulates immunity

Types of vaccines?

:Live attenuated, inactivated, subunit, toxoid, nucleic acid

Are some vaccines better?

:Choice depends on safety and immunity needed

What is epidemiology?

:Study of disease distribution

Why study epidemiology?

:To track and prevent disease

Stages of clinical infection?

:Incubation, prodromal, illness, decline, convalescence

What must you understand about infections?

:Causative agent, symptoms, pathogenesis, epidemiology, treatment, prevention

Major respiratory infections?

:Upper and lower respiratory infections

How are respiratory infections spread?

:Droplets and aerosols

Why are lower respiratory infections worse?

:They affect lungs

Why do skin infections look similar?

:Inflammation response

Why specify rash type?

:Different diseases cause similar rashes

Types of wounds?

:Puncture, abrasion, laceration

Why are wounds infected by normal flora?

:Skin barrier is broken

Why are wound infections dangerous?

:Can spread systemically

Organs of digestive tract?

:Mouth, stomach, intestines

Oxygen levels in digestive tract?

:High in stomach, low in intestines

Why does oxygen matter?

:Determines which microbes can grow

How can genitourinary infections be prevented?

:Hygiene and safe sex

Which infections persist for life?

:Herpes, HPV, HIV

Difference between urinary and genital systems?

:Urinary removes waste, genital involved in reproduction

Why can meningitis have many causes?

:Many microbes can cross blood-brain barrier

How do prions infect nervous system?

:Misfold proteins

How does rabies affect nervous system?

:Travels through nerves to brain

What is the blood and lymphatic system?

:Transport and immune systems