Assessment 1

What types of organisms do microbiologists study? 


• viruses

• bacteria

• archea

• protists (including protozoa)

• fungi

• helminths

What topics fall under the scope of microbiology?


• microbial structure

• microbial metabolism

• microbial genetics

• microbial control

• host defenses

• host-microbe interactions

• disease

• disease spread

• infection control

• diagnostics

• food micro

• industrial micro

• environmental micro

Factors that affect the ability of microbes to live & grow:


• nutrient source-(autotrophs/Self-feeding vs heterotrophs/need chemicals from other sources)

• energy source -(chemotrophs/chemicals vs phototrophs/light)

• reproduction

• metabolism

• water/moisture

• appropriate temperature

• appropriate pH

• appropriate gas environment

prokayotes

• have small simple cells

• lack a nucleus & other internal membrane-bound structures

• all bacteria & archea

eukayotes

• larger

• more complex cells

• have a nucleus & other internal membrane -bound structures

• all other cellular organisms

viruses

• simple

• no cells

• do not carry out metabolism

• smallest type of microbe

• too small to see with conventional microscope

bacteria

• small, single celled prokaryotes

• vary in how they obtain energy & nutrition

• small percentage cause disease in humans

archea

• small, single celled prokaryotes

• similar to bacteria, different genetically & chemically

• live in extreme environments

protists (including protozoa):

• single celled enkaryotes

• includes protozoa & some algae

• larger than bacteria

• have a nucleus

fungi

• single or multicellular eukaryote

• cell walls absorb nutrients

helminths (including parasitic worms):

• multicellular animal adults are

• often easy to see with a naked eye

correct format of scientific name:

• Genus species

• Genus: capitalized

• Species: lower case

• italics or under lined

• Cytoplasmic membrane (or cell/plasma):

• lipid bilayer membrane that separates the separates the inside of the cell from the environment

• defines the boundary of the cell

• regulate what can enter & leave the cell

cytoplasm (cytosol):

• liquid portion of cutoplasm

• fluid & suspended contents of the cell

• mostly water, but includes dissolved nutrients. suspended particles & enzymes

chromosome (DNA):

• genetic material

• prokaryotes: singular circular molecule of DNA in nucleoid region

• eukaryotes: multiple DNA chromosomes inside nucleus

ribosomes

• site of protein synthesis

• way to make proteins

cytoskeleton

• protein fibers running through the cytoplasm

• involved in cell division a maintaining cell shape

cell wall (prokaryotes):

• rigid structure outside of membrane

• provides structural support & protection

Gram positive

thick walls & peptioglycan anchored to the cytoplasmic membrane

Gram negative

• thin peptiogylcan wall

• outside the wall is a second membrane that can cause toxic reactions in humans when cells break down

acid fast

thick, waxy walls made of mycolic acid

capsule (thick, gel layer) glycocalyx (thin, slime layer):

• on the outside cell wall of some bacteria

• helps bacteria stick to each other

• makes it hard for white blood cells to destroy bacteria

flagella

whip like tails for movement

fimbriae

numerous short, sticky projections in some Gram negative bacteria for adhesion

plasmids

• small circular pieces of DNA that are not past of the chromosome

• contain essential genes such as drug resistant genes

pilli

• hollow protein tubes projecting from the surface of some bacteria

• used for exchange in genetic material

endospores

tough, resistant, dormant structure made by a few types of bacteria (Gram Positive)

nucleus

• eukaryotes must contain

• membrane bound compartment for chromosomes

mitochondria

• eukaryotes must contain

• energy production

endoplasmic reticulum:

• eukaryotes must contain

• membrane system

• production of protein & lipids

Golgi apparatus

• eukaryotes must contain

• shipping & receiving

peroxisomes:

• eukaryotes must contain

• contain enzymes to allow cells to deal with toxic chemicals

lysomes

compartments with digestive enzymes

cillia:

finger like projections for movement

cell wall (eukaryotes)

• in plants, fungi, & protists

• provide rigid structure around cell

cell parts in prokaryotes only:

• pili

• endospores

cell parts in eukaryotes only:

• nucleus

• mitochondria

• endoplasmic reticulum

• peroxisomes

• cillia

cell parts in both

• cytoplasmic membrane

• сytoplasm

• chromosomes

• ribosomes

• cytoskeleton

• flagella

• cell walls