Module 01 - Introduction to Microbial Cells

Question 1

Define “spontaneous generation”

Answer 1

life can arise from nonliving matter

Question 2

How did Francesco Redi test spontaneous generation?

Answer 2

• performed an experiment on the notion of spontaneous generation
• refute the idea of spontaneous generation that maggots can spontaneously generate from meat left in open air
• 6 containers - 2 open to air, 2 covered with gauze, and 2 completely closed
• maggots formed only to the jar that was left completely open, this was because of the presence of flies on the meat, causing maggots to form

Question 3

How did John Needham test spontaneous generation?

Answer 3

• boiled broth of animal and plant matter to kill preexsiting microbes
• broth became cloudy (sealed jars)
• microbes were still in the broth
• argued that the microbes had arised spontaneously
• reality: he didnt boil the broth enough to kill the microbes

Question 4

How did Lazzaro Spallanzani test spontaneous generation?

Answer 4

• didn’t agree with Needhams results
• performed same experiment as Needham but with many different jars
• used sealed and unsealed jars
• heated but sealed flasks clear with no sign of spontaneous generation, unless the jars were left open
• microbes were introduced to the jars from the air

Question 5

Microbe

Answer 5

a microorganism, especially a bacterium causing disease or fermentation.

Question 6

Louis Pasteur - spontaneous generation

Answer 6

• flasks were able to exchange air from outside
• bends and twists in the flask wouldn’t allow for air to come in, unless broken
• airborne microorganisms allow microbes to grow in the broth
• “life is a germ and germ is life”
• boiling the broth kills the microorganisms

Question 7

Cell Theory

Answer 7

is a scientific theory first formulated in the mid-nineteenth century, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells

Question 8

Two basic tenets of cell theory

Answer 8

• all cells only come from other cells (principle of biogensis)
• cells are a fundamental units of organisms

Question 9

Endosymbiotic Theory

Answer 9

is the leading evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms (symbiogenesis)
- defined as the theory that mitochondria and chloroplasts arose as a result of prokaryotic cells establishing a symbiotic relationship within a eukaryotic host

Question 10

Germ theory of disease

Answer 10

diseased may result from microbial infection

Question 11

Distinguish characteristics of prokaryotic cells

Answer 11

• smaller than eukaryotic cells
• have no nucleus
• lack organelles
• singular, circular chromosome in the nucleiod
• classified as Archaea and Bacteria
• lack membrane bound organelles, inclusions to compartmentalize for cytoplasm

Question 12

Organelles in prokaryotic cells

Answer 12

plasma membrane, cell wall, capsule, cytoplasm, ribosome, nucleiod, inclusion, plasmid, pilus, and flagellum

Question 13

Cell Wall

Answer 13

envelopes the cell membrane protecting the cell from osmotic pressure
protects cell from harsh conditions in outside environment, main component of cell wall - peptidoglycan

Question 14

isotonic membrane

Answer 14

solute concentration inside and outside of cell are equal, not net movement of water

Question 15

hypertonic medium

Answer 15

solute concentration outside cell is more than inside, water diffuses out of cell

Question 16

hypotonic medium

Answer 16

solute concentration inside cell is higher than outside, water moves by osmosis into cell (cell can swell and burst)

Question 17

Crenation

Answer 17

cell can become dehydrated in hypertonic environment

Question 18

plasmolysis

Answer 18

(cell with cell wall) plasma membrane contracts and detaches from cell wall for shape

Question 19

Nucleoid

Answer 19

prokaryotic DNA and DNA proteins, DNA interacts with nucleiod - associated proteins (NAPs)

Question 20

plasmids

Answer 20

extrachromosomal DNA found, plasmids found in bacteria

Question 21

ribosomes

Answer 21

constructed of proteins and rRNA, found in cytoplasm

Question 22

inclusion

Answer 22

store excess nutrients in cytoplasmic structures (ex. glycogen, starches and polyhydroxybutyhate)

Question 23

endospores

Answer 23

bacteria cells are observed as vegetative cells, bacteria can form endospores
a dormant, tough, and non-reproductive structure produced by certain bacteria

Question 24

plasma membrane

Answer 24

eukaryotic and prokaryotic cells have a plasma membrane
he membrane found in all cells that separates the interior of the cell from the outside environment

Question 25

flagella

Answer 25

structures to move in aqueous environment

Question 26

eukaryotic cells

Answer 26

are organisms whose cells have a nucleus enclosed within a nuclear envelope. They belong to the group of organisms Eukaryota or Eukarya

Question 27

nucleus

Answer 27

complex nuclear membrane that houses the DNA genome

Question 28

nucleolous

Answer 28

region in the nucleus where RNA occurs, assembly of ribosomes occur

Question 29

ribosomes

Answer 29

eurkaryotes are 80S ribosomes (40S small subunit and 60S large subunit) - ribosomes are defined by location: free ribosomes and membrane bound ribosomes - free ribosomes in cytoplasm - membrane bound ribosomes attached to rough ER

Question 30

endomembrane system

Answer 30

unique to eukaryotes, several organelles and connections between them (ER, golgi, lysosomes, vesicles)

Question 31

endoplasmic reticulum

Answer 31

rough ER is studded with ribosomes bound on cytoplasmic side of membrane, smooth ER has no ribosomes (appears smooth)

Question 32

golgi apparatus

Answer 32

series of membranous disks, single lipid bilayer that are stacked together

Question 33

lysosomes

Answer 33

membrane-bound organelles, used to breakdown food, damaged organelles or cellular debirs

Question 34

peroxisomes

Answer 34

independent from cytoplasm from perchin proteins

Question 35

cytoskeleton

Answer 35

internal cytoskeleton made of microfilaments, intermediate filaments and microtubules

Question 36

centrosomes

Answer 36

(mitotic spindles) microtubule-organizing centres, at end of cells

Question 37

centrioles

Answer 37

(pairs) right angles of each other, each centriole of nine parrallel microtubules arranged in triplets

Question 38

mitochondria

Answer 38

powerhouse of the cell - gives energy to cell

Question 39

mitochondrial matrix

Answer 39

location of original bacteriums cytoplasm, and current location of metabolic enzymes, contains mitochondrial DNA and 70S ribosomes

Question 40

chloroplasts

Answer 40

photosynthesis occurs, three systems: outer membrane, inner membrane and thylakoid membrane system

Question 41

stroma

Answer 41

(gel like fluid that makes up the volume)

Question 42

endocytosis

Answer 42

plasma membrane invagination and vacuole vesciles formation

Question 43

phagocytosis

Answer 43

engulfing of large particles I"cell eating")

Question 44

pinocytosis

Answer 44

other type of endocytosis ("cell drinking")

Question 45

receptor-mediated endocystosis

Answer 45

type of endocytosis ligards bind to surface receptors on membrane

Question 46

extracellular matrix

Answer 46

eukaryotic cells that dont have cell walls have the matrix, A large network of proteins and other molecules that surround, support, and give structure to cells and tissues in the body. The extracellular matrix helps cells attach to, and communicate with, nearby cells, and plays an important role in cell growth, cell movement, and other cell functions.

Question 47

flagella in eukaryotes

Answer 47

locomoiton, very distinct compared to prokayotes

Question 48

cilia

Answer 48

unique to eukaryotes, covers entire surface of cell

Question 49

Similarities of Eukaryotes and Prokaryotes

Answer 49

cell membrane, cytoplasm, genetic material for DNA and ribosomes

Question 50

Differences between Eukaryotes and Prokaryotes

Answer 50

eukaryotes have membrane-bound nucleus, prokaryotes dont

Question 51

Unique examples of prokaryotes in various habitats on earth

Answer 51

found in hot springs, antarctic ice shield under extreme conditions

Question 52

Community

Answer 52

group of interacting population of organisms

Question 53

cooperative interactions

Answer 53

(part of population) benefit populations

Question 54

competitive interactions

Answer 54

a population competes with another for resources

Question 55

microbial ecology

Answer 55

study of interactions between microbial populations and environments

Question 56

symbiosis

Answer 56

interaction between different species that are associated with each other in a community

Question 57

mutualism

Answer 57

(syntropy, crossfeeding) two species benefit from each other

Question 58

Amensalism

Answer 58

one population that harms another but is unaffected - substances that kills other species of bacteria

Question 59

commensalism

Answer 59

one organism benefits while the other is unaffected - ex. bacteria can live on our skin, but we remain unaffected/dont react

Question 60

neutralism

Answer 60

neither symbiotic organism is affected - ex. active bacteria and endospores

Question 61

parasitism

Answer 61

one organism benefits while harming another

Question 62

microbiomes

Answer 62

all prokaryotic and eukaryotic microorganisms and genetic material associated to an organism or environment

Question 63

resident microbiota

Answer 63

microorganisms that live in/on our bodies

Question 64

transient microbiota

Answer 64

microorganisms that are temporarily found in human body (pathogenic microorganisms)

Question 65

how are prokaryotes classified by microbiologists?

Answer 65

based on shape, staining patterns, biochemical or physiological differences - nucleotide sequences in genes - staining patterns are based on cell walls

Question 66

algae

Answer 66

autotrophic prostists that can be unicellular/mutlicellular, algae are sources of agar, agarose and carrageenan, algae uses toxins

Question 67

lichen

Answer 67

combinations of two organisms , a green alga, or cyanobacterium and fungus, living in a symbiotic relationship

Question 68

epiphytes

Answer 68

lichen can be found on most surfaces or grow on other plants

Question 69

cortex

Answer 69

body called a thallus, an outer, tightly packed fungal layer

Question 70

medulla

Answer 70

inner, loosely packed fungal layer

Question 71

mizines

Answer 71

hyphal bundles

Question 72

why are viruses acellular?

Answer 72

because they are not considered alive