MCB 3020 Final Questions With Complete
Solutions
Microorganisms/Microbes - ....ANSWER ....✔✔ -Small
living organisms that can't be seen by the human eye
- diverse in form/funtion
- inhabit every EVR that supports life
- many single celled, some form complex structures, some
multicellular
- live in microbial communities
Microorganisms/Microbes - ....ANSWER ....✔✔ -
oldest form of life
- major fraction of earth's biomass
- surround plants and animals
- affect human life (infectious diseases, food and water,
soils, animal health, fuel)
tools for studying microorganisms - ....ANSWER ....✔✔
-microscopy, microbiology lab
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culture - ....ANSWER ....✔✔ -cell grown in/on nutrient
medium
-growth to form a visible colony
medium - ....ANSWER ....✔✔ liquid/solid mixture
containing all required nutrients
culture growth - ....ANSWER ....✔✔ lawn growth
toward right
colonial growth towards left
cell - ....ANSWER ....✔✔ living compartment that
interacts with the environment and other cells
Elements of microbial structure - ....ANSWER ....✔✔
cytoplasmic membrane, cytoplasm, ribosomes, cell wall
cytoplasmic membrane - ....ANSWER ....✔✔ barrier
that separates the inside of the cell from the outside
environment
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Cytoplasm - ....ANSWER ....✔✔ aqueous mixture of
macromolecules, small organics, ions, and ribosomes
inside cell
Ribosomes - ....ANSWER ....✔✔ - protein synthesizing
structures
* sites of protein syn.
* thousands of ribosomes per cell
* composed of two subunits (30s and 50s in prok.) to
form 70s ribosome
... s= svedberg units
* combo. of rRNA and protein
* E.coli has 52 distinct ribosomal proteins
cell wall - ....ANSWER ....✔✔ present in SOME
microbes; confers structural strength
Prokaryotic vs. Eukaryotic - ....ANSWER ....✔✔
Prokaryotic - no nucleus, no membrane bound
organelles, smaller, bacteria and archaea
Eukaryotic - has nucleus, DNA enclosed in a membrane
bound organelles, larger, animals fungi protozoa plants
& algae
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genome - ....ANSWER ....✔✔ The complement of an
organism's genes; an organism's genetic material
Eukaroytic DNA - ....ANSWER ....✔✔ - linear
chromosomes within nucleus
- much larger/more DNA (up to BILLIONS of base pairs)
Prokaryotic DNA - ....ANSWER ....✔✔ - single circular
chromosome that aggregates to form the nucleoid
region
- may have plasmids (extra chromosomal DNA) that
confer special properties (e.g., antibiotic resistance)
- small, compact (0.5-10 MILLION base pairs)
activities of microbial cells - ....ANSWER ....✔✔ cells
typically live in microbial communities
Metabolism (properties of all cells) - ....ANSWER
....✔✔ - chemical transformation of nutrients
- transform nutrients, and expel wastes
- genetic: replication, transcription, translation
- catalytic: energy, biosyntheses