Microbiology Exam 1- Ch. 1,3,4,5,7

decomposer

an organism (usually bacteria or fungi) that breaks down dead organic matter into simpler substances, recycling nutrients back into the environment

pathogen

a microorganism capable of causing disease in a host

sterile

completely free of all living microorganisms, including bacteria, viruses, fungi and spores

eukaryotes

-organisms whose cells contain a membrane-bound nucleus and other membrane-bound organelles

-fungi, protozoa, plants, animals

biotechnology

the use of living organisms, cells, or biological systems to develop products or processes for medical, industrial, or environmental applications

media (culture media)

nutrient substances used to grow, culture and maintain microorganisms in a lab

prokaryotes

-organisms whose cells lack a nucleus and organelles

-bacteria, archaea

bioremediation

the use of microorganisms to break down or remove environmental pollutants, such as oil spills or toxic chemicals

endospore

highly resistant, dormant structure formed by certain bacteria to survive extreme environmental conditions

fermenter

a vessel or system used to grow microorganisms under controlled conditions to produce fermentation products such as alcohols, acids, or antibiotics

prion

-an infectious, misfolded protein that causes disease by inducing abnormal folding of normal proteins

-contains no DNA or RNA

plasmid

-a small, circular, double-stranded DNA molecule found in bacteria that replicates independently of the chromosome and often carries beneficial genes, such as antibiotic resistance

capsomere

protein subunit that assembles to form the capsid (outer protein coat) of a virus

microorganism

microscopic living organism, including bacteria, archaea, protozoa, fungi, and microscopic algae

chemotaxis

directed movement of a cell or organism toward or away from a chemical stimulus

epidemiology

study of the distribution, causes and spread of diseases within populations

reverse transcriptase

enzyme that synthesizes DNA from RNA template; commonly found in retroviruses

lysogeny

viral reproductive cycle in which viral DNA integrates into the host cell's genome and replicates with it without immediately destroying the host

Bergey's Manual of Determinative Bacteriology

organizes bacteria according to phenotypic traits commonly used in lab identification

mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Have their own DNA and double membrane

Involved in apoptosis (programmed cell death)

fungi

Which group contributes significantly to decomposition and nutrient recycling?

cytoskeleton

Which part of the cell is responsible for anchoring organelles and enabling cell shape changes?

smooth ER

involved in lipid synthesis and detoxification.

It produces phospholipids and steroids used to build cell membranes, detoxifies drugs and harmful chemicals (especially in liver cells), and stores calcium ions, which are important for cell signaling and muscle contraction.

algae

Which group is responsible for producing around 70% of the Earth's oxygen?

cell wall

Which structure is present in fungi and algae but absent in protozoa and animals?

diplococci

cocci arranged in pairs

biofilm

mixed microbial communities living cooperatively

flagella

appendage used for motility in bacteria

attachment

A bacteria's fimbriae are primarily used for:

gram positive bacteria

-bacteria with a thick peptidoglycan layer

-stain purple in a gram stain

gram negative bacteria

-bacteria with a thin peptidoglycan layer

-stain pink/red in a gram stain

-have an outer membrane

obligate

Viruses are _______ intracellular parasites.

They are dependent on a host cell to replicate their genetic material.

virion

a fully formed virus that is able to establish an infection in a host cell

capsid

Protein shell surrounding viral genome.

naked viruses

viruses that lack an envelope around the capsid

glycoproteins

Viral spikes are made of _______

bacteriophage

virus that infects bacteria

either RNA or DNA, but never both

What does the viral genome consist of?

positive sense RNA

-Negative sense RNA is complementary to mRNA and not directly recognized by ribosomes.

-Negative sense RNA must first be converted into _________

-It can then be translated into proteins by the host cell.

nucleus

cytoplasm

DNA viruses replicate in the _______

RNA viruses replicate in the ________

plaque

A clear zone in a bacterial lawn caused by a viral lysis is called a _______

-spikes

-they bind to specific receptors on the host cells

Which viral structure determines host specificity?

capsomeres- assemble to form the capsid

Which viral component is composed of identical protein subunits?

budding

Enveloped viruses typically exit the host cell by _______.

They acquire their outer lipid envelope by pushing through a host membrane without immediately causing cell lysis.

they lack nucleic acids entirely

Why do prions differ from viruses?

incubation

Which of the 5 I's allows microbes to multiply?

lysogenic cycle

-virus infects a bacterium but doesn't destroy it right away

-virus injects its DNA into bacterial cell and the viral DNA joins the bacterium's DNA

-the bacterium then goes on living and dividing normally, copying the viral DNA each time it reproduces

lysogenic

lytic

cycle where the virus invades the cell is _______

cycle where the virus hijacks and kills the cell is ________

lytic cycle

-virus infects a bacterium and quickly destroys it

-virus injects its DNA into bacterial cell, takes over the cell's machinery, and uses it to make many new viruses

-once enough new viruses are made, the bacterial cell bursts open (lyses), releasing the viruses to infect other bacteria

ribosomes

bacterial structure responsible for protein synthesis

alcohol decolorizer

During the Gram stain, which step removes crystal violet from the Gram negative cells?

lophotrichous

a tuft of flagella coming from one pole

peritrichous

flagella distributed over the entire cell

amphitrichous

flagella at both ends of cell

monotrichous

single flagellum at one end

actin-like filaments

cytoskeletal component responsible for maintaining cell shape in bacteria

streptococci

chains of cocci

fastidious microorganisms

organisms that require specific, complex nutrients that must be applied in enriched media

lytic infection (fast)

Which type of viral infection leads to rapid host cell lysis?

latent infection

infection in which the infectious agent is present but not causing symptoms (persistent)

assembly

Which viral replication step involves the assembly of capsomeres around nucleic acids?

lysosome

organelle responsible for digesting engulfed particles in eukaryotic cells

cytoplasm

bacterial structure that is the site of most metabolic reactions

streak plate

lab technique that spreads bacteria across a plate to isolate

uncoating

viral replication step that involves removal of the capsid (surrounds the genome)

Robert Koch

Who first determined that Bacillus anthracis and Mycobacterium tuberculosis were the causes of anthrax and tuberculosis?

peptidoglycan

-compound that makes up the bacterial cell wall

-made of NAG and NAM subunits

1. crystal violet

2. iodine

3. alcohol

4. safranin

What are the steps of a Gram Stain in order?

positive chemotaxis

If an organism with flagella is near a chemoattractant, what is the process of directing movement towards a chemical signal called?

they lack the machinery necessary for protein synthesis (obligate intracellular parasites)

smaller than bacteria

only active inside host cells

can have dsDNA, ssDNA, or dsRNA

What are some fundamental properties of viruses?

Koch's Postulate

a set of criteria that establishes a relationship between a microbe and a disease

sterilization

cleaning method that removes all microbes

basal body

hook

filament

What are the 3 components of a flagella?

lysogenic cycle

A prophage is associated with which viral process?

prophage

-viral DNA from a bacteriophage that is inserted into a bacterium's DNA

-stays inactive inside the cell during the lysogenic cycle and is copied along with bacterial DNA until it becomes active and enters the lytic cycle

bacteria

Which domain includes organisms with peptidoglycan in their cell walls?

it lyses and releases newly assembled phages

In the lytic cycle, what happens to the host cell at the end of infection?

Antonie van Leeuwenhoek

In the 1670s, who was the first to see and describe bacteria and protozoa using handcrafted microscopes?

Edward Jenner

In 1796, who developed the first vaccine?

Used cowpox to protect against smallpox

Louis Pasteur

In the 1860s, who established Germ Theory?

Demonstrated that microorganisms cause fermentation and disease; developed pasteurization

John Tyndall

In the 1870s, who confirmed Germ Theory?

Showed that dust carries microorganisms and developed Tyndallization (a method to sterilize using intermittent boiling)

Joseph Lister

In 1867, who introduced antiseptic surgery?

Used carbolic acid (phenol) to sterilize surgical tools and wounds, dramatically reducing infections

Robert Koch

In 1876, who identified Bacillus anthracis?

Introduced Koch's postulates for linking microbes to certain diseases

the bacteria responsible for TB, cholera and the plague were discovered, isolated and studied

What major contribution happened in the 1880s-1890s?

Alexander Fleming

In 1928, who discovered penicillin?

Marks the beginning of the antibiotic era

-discovered that DNA is hereditary material

-found that DNA, not protein, carries genetic info

In 1944, what did Avery, MacLeod and McCarty discover?

Watson and Crick

In 1953, who described DNA's double helix structure?

archaea

In 1977, what did Carl Woese discover?

Reclassified the tree of life using RNA sequencing

PCR (polymerase chain reaction)

allowed scientists to amplify DNA rapidly and revolutionized molecular biology and diagnostics

In 1983, what did Kary Mullis invent?

HIV- the virus responsible for AIDS

What was discovered in 1983?

first bacterial genome sequenced- Haemophilus influenzae

What major contribution happened in 1995?

CRISPR- gene editing and microbiome research

derived from bacterial immune systems

expanded understanding of human health through gut biome research

What major contribution arose in the 2000s and is still developing today?

COVID epidemic

microbiologists led the way to rapid identification, genome sequencing, testing and vaccine development for SARS-CoV-2

What major event happened in 2020 that microbiologists led a global response to?

adsorption

Which step of the multiplication cycle of RNA animal viruses is this?

The virus attaches to its host cell by specific binding of its spikes to cell receptors.

penetration

Which step of the multiplication cycle of RNA animal viruses is this?

The virus is engulfed into a vesicle

uncoating

Which step of the multiplication cycle of RNA animal viruses is this?

The envelope of the virus is opened, which frees the viral RNA into the cell cytoplasm.

synthesis

Which step of the multiplication cycle of RNA animal viruses is this?

Replication and Protein Production: under the control of viral genes, the cell synthesizes the basic components of new viruses (RNA molecules, capsomeres, spikes)

assembly

Which step of the multiplication cycle of RNA animal viruses is this?

Viral spike proteins are inserted into the cell membrane for the viral envelope; nucleocapsid is formed from RNA and capsomeres

release

Which step of the multiplication cycle of RNA animal viruses is this?

Enveloped viruses bud off of the membrane, carrying away an envelope with the spikes. This complete virus, or virion, is ready to infect another cell.

gram negative

What type of bacteria are E coli and salmonella?