Microbiology Exam 2 Flashcards

Nutrients, Temperatures, pH, Amount of water available, atmospheric gases, Light, pressures, and other organisms

C-Carbon
H-Hydrogen
O-Oxygen
P-Phosphorus
S-Sulfer
Nitrogen

Na-sodium
Cl-chlorine
K-potassium
Ca-calcium
Fe-iron
Mg-magnesium

an organic nutrient(amino acid, nitrogenous base, or vitamin) that cannot be synthesized and must be provided as a nutrient

Autotroph-chemoautotroph and photoautotroph
Heterotroph-saprobe (dead organisms) and parasite

organisms that obtain inorganic source such as co2 as its carbon source and is not nutritionally dependent on other organisms for their survival

nutritionally dependent on organic source from other organisms.

Microbial cells must take in nutrients from their
surroundings by transporting them across the cell
membrane

molecules that are taken into the cell by a process that requires energy

( carrier mediated active transport, group, translocation, phagocytosis, pinocytosis )

involves the natural movement of substances down a concentration gradient and requires no additional energy

( simple or facilitated diffusion )

cells shrink or crenate (distorted)

cells swell and burst (lyse)

no net diffusion of water
rate of diffusion are equal

Halophile

organisms that have adapted to high salt concentrations (15-20% salt) that the require them for growth

molecules readily pass through the cell membrane

molecules pass through the cell membrane via a carrier protein

Phagocytosis is considered cell “eating” (brings in solid to the cell)

Pinocytosis is considered cell "drinking" (bring in liquid to the cell)

organisms that thrives between temperature of 10-50 degree Celsius.

organisms that thrives between temperature of 45-80 degree Celsius.

organisms that thrives between temperature of -20-15 degree Celsius.

Anaerobe that cannot grow in the presence of oxygen (O2)

anaerobe that cannot use oxygen (O2) but is not injured by it

aerobe capable of living without oxygen (O2)

requires a small amount of O2 but does not grow under anaerobic conditions

organism that thrives in pH below 7pH (acidic environment)

organism that thrives in pH above 7pH (alkaline environment)

organism that thrives in 7pH (neutral environment)

organism that thrives in high barometric pressure

organisms that live in close nutritional relationships; required by one or both members (Mutualism, Commensalism, Parasitism all dependent on one another for survival)

Obligatory dependent; both members benefit

The commensal (bacteria living in another bacteria) benefits; other members are not harmed.

Parasite is dependent and benefits; the host is harmed.

organisms that are free-living; relationships not required for survival (Synergism and Antagonism)

Members cooperate and share nutrients

Some members are inhibited or destroyed by others.

an interaction among members of abiofilm that results in a coordinated reaction such as secreting an enzyme

binary fission

4 phases.
-Lag Phase-period of adaption (adjustment)
-Experimental Growth Phase-growth balances out
-Stationary Phase-population enters survival mode
-Death Phase-nutrients run out, and death occurs

the sum of all chemical and physical activities in a cell

is made possible by enzymes that speed up chemical reactions by lowering the energy of activation

Large molecules that are degraded back into a smaller molecule

reactions that convert smaller molecules into larger molecules

Enzymes that has a specific substrate and will only recognize its own type to bind with. (Lock and Key)

They all end with “ase”

Their name states what they do. i.e Oxidase-add electron to "Oxygen". Nitrate Reductase-reduce nitrate to nitrites.

reactions that involves addition of water to break bonds

reactions that involve releasing water to form bonds

Oxidized=remove of hydrogen-loss of (H+)
Reduced= Adding of Hydrogen-Gain (H+)

the term for loss of three-dimensional structure of a protein

– Heavy metals
– Alcohol

a substrate-like molecule binds the enzyme and blocks it from binding to its natural substrate

the regulator molecule does not bind the same
site as the natural substrate

Endergonic reactions consume energy use(ATP)

Exergonic reactions release energy create(ATP)

Endergonic reactions consume energy use(ATP) and Exergonic reactions release energy create(ATP)

2 ATP and 2 NAD's

2 Pyruvates (each pyruvates goes through the steps and Crebs-cycle once)

2 ATP and 8 Electron

Mitochondria

Cell Cytoplasm

ATP Synthase

photons are absorbed by chlorophyll, water is split by photolysis, oxygen is released, and electrons released drive photophosphorylation
(H+ + ADP + ATP synthase -> ATP)

LIGHT IS NEEDED

(Calvin cycle) use ATP to fix CO2 to a carrier (RIBULOSE-1,5-BISHOPHATE) and convert it to glucose in a multi-step process.

LIGHT DOESNT MATTER

provide the information needed to construct proteins (enzymes)

long molecule in the form of a double helix

the basic structural unit of DNA that are composed of
– Phosphate
– Deoxyribose (sugar)
– Nitrogen base(A,T,C,G)

- Organism
– Genome
– Chromosome
– Gene
– DNA

Each daughter cell contains a parent strand and a
newly-synthesized complementary strand

contains codons (groups of three consecutive
nucleotides)that pair with anticodons on the tRNA to specify which amino acid to assemble on the ribosome during translation

Single-stranded instead of double-stranded
Contains uracil (U) instead of thymine (T)
Contains ribose instead of deoxyribose

mRNA, tRNA, rRna

message based on the DNA sequence, contains codons

brings amino acids to the ribosome during
translation, contains anticodons

major part of the ribosome

contains codons (groups of three consecutive nucleotides that pair with anticodons on the tRNA to specify which amino acid to assemble on the ribosome during translation

the process by which DNA is used to produce RNA

occurs when RNA polymerase copies the template strand of DNA

(RNA->Protein) occurs when the RNA is used to direct the synthesis of proteins on the ribosome
– Begins at a “start” codon (AUG)
– Ends at a “stop” codon (UAA, UAG, or UGA)

promoter, operator and terminator

When the repressor is bound to the operator, transcription does not occur BUT When the repressor is not bound to the operator, transcription occurs.

at the same time(both occur in the cytoplasm)

they occur separately and in different parts of the cell (transcription occurs in the nucleus and
translation occurs in the cytoplasm)

• In eukaryotes the mRNA must also be processed before translation can occur.
• Contains introns (intervening sequences) and exons (expressed sequences), where the introns must first be removed

The sequence between the “operator” and “terminator” contains the genes

Promotor, Operator, Terminator, and Genes

where transcription stops

where RNA polymerase binds

where repressor molecules bind

An inducer molecule

In the absence of glucose,(even if lactose is present)lactose can be broken down and used for energy; certain enzymes are required for this process and are encoded by the Lac Operon

The Tryptophan Operon: Usually on and making tryptophan; when enough tryptophan is present the operon is turned off

Mutations can be detected using selective
media and the replica plating technique.

change that leads to placement of a different amino acid by the ribosome (cause amino acid to change)

changes a normal codon into a stop codon (premature stopping)

alters a base but does not change the amino acid and thus has no effect

a gene that has undergone mutation reverses to the non-mutated state (mutated genes revert back to its original state)

fixes UV damage

fixes mismatched bases

measures the mutagenicity of chemicals by their ability to induce mutations in bacteria

bacterial mating where DNA is transferred from one cell to another via the pilis

the transfer of naked DNA from the environment to the bacterial cell through special receptors on the cell surface

a process where viruses insert bacterial DNA into bacteria accidentally in nature

-We can also do this in the lab by placing DNA into a bacterial virus and then infecting bacterial cells

Also called “jumping genes” are segments of DNA that regularly move to different places within the genome of a cell generating mutations and variations in chromosome structure

viruses can be double-stranded or single-stranded, and can be RNA or DNA

DNA viruses tend to replicate in the nucleus while
RNA viruses tend to replicate in the cytoplasm

procedures involve the destruction or removal of contaminants

defined as microbes present at a given place and time that are undesirable or unwanted

a process that destroys or removes all microbes, including viruses

chemicals that destroys bacteria

agents that temporarily prevent growth of microbes

chemicals that will kill any pathogenic microorganism

microbicidal destroys bacterias while microbistatic agent temporarily prevent growth of microbes.

I.E Microbistatic is similar to a fridge (coolness slow bacteria growth)

They work by targeting either
- Cell wall synthesis and break the cell wall down
– Membrane permeability and lyses the lipids
– Protein and nucleic acid synthesis and function, it denature proteins

Temperature 120C @ 15psi, 20 minutes

subjects liquids to temperatures below 100C and is used to lower the microbial load in liquids

A widely used method is the flash method
• 71.6C for 15 seconds
Another method is the batch method
• 66C for 30 minutes

Boiling water at 100C for 30 minutes disinfects, but does not sterilize

Incineration can be carried out using a Bunsen
burner or incinerator
• Temperatures range between 800C to 6500C

Drying and desiccation lead to (often temporary) metabolic inhibition by reducing water in the cell (drying not killing all bacterias)

Energy in the form of radiation can be used for
cold sterilization
– Works by killing microbes without heat

Filtration involves the physical removal of
microbes by passing a gas or liquid through a
fine filter
• Air and heat-sensitive liquids can be sterilized using this method

causes breaks in DNA (xrays)

Creates dimers in DNA stopping communication (UV-Light)

destruction of vegetative cells on animate (living object/surfaces) surfaces

clean inanimate (nonliving object/surfaces) objects using soap and degerming agents to achieve a “safe level” of microbes

(removes microorganisms to “safe levels or standards”)

physically remove surface oils, debris, and soil
from skin to reduce the microbial load

destruction of vegetative cells on inanimate (nonliving object/surfaces)surfaces

(destroys vegetative pathogens but not bacterial endospores)

Chlorine disrupt disulfide bonds in PROTEINS and
can be sporicidal

– Iodine works similarly to chlorine

Phenolics disrupt CELL MEMBRANES and precipitate PROTEINS

Bisphenols are mild forms for disinfection and
antisepsis (BPA)

surfactant and a protein denaturant (CELL MEMBRANE)

Solutions are found in skin degerming agents for preoperative scrubs, skin cleaning, and burns

Ethyl and isopropyl alcohol, in concentrations of 50-90% act as surfactants
– Dissolve membrane LIPIDS and denature proteins

Hydrogen peroxide damages protein and DNA, while also decomposing to O2 gas which is toxic to anaerobes

Detergents, known as quaternary ammonium compounds (quats) act as surfactants that alter membrane permeability

Soaps have little microbicidal activity but, rather, function by removing grease and soil
that contain microbes

Heavy metals inactivate proteins