bios 350- week 3

binary fission

symmetrical asexual division of bacteria

batch culture

these cultures do not allow nutrients to flow in or waste to flow out during the growth phase; instead, they are grown in a closed system where the cells grow until nutrients are exhausted.

log phase

phase of bacterial growth with exponential population increase

stationary phase

Phase of bacterial growth with secondary metabolite production

lag phase

Phase of bacterial growth focused on bacterial adaptation

stationary phase

In this phase of growth, the bacterial growth rate is the same as the death rate

death phase

In this phase of growth, the bacterial growth rate is lower than the death rate

log phase

Phase of bacterial growth where nutrients are metabolized to produce primary metabolites

doubling time

Amount of time it takes for bacteria to divide

log phase

When are bacteria more susceptible to antibiotics

selective media

Type of growth medium that allows for the growth of certain types of bacteria while inhibiting others

biofilms

a community of microorganisms encased in a self-produced extracellular matrix

continuous culture

these cultures allow nutrients to flow in or waste to flow out

microcolonies

the first few cells of a biofilm form

exopolysaccharide

sticky substance that forms channels for biofilms to be continuous

quorum sensing

bacterial communication through the release and receipt of small peptides/chemicals

differential media

these media may use colors to distinguish different microbes

complex media

media that contains a variety of nutrients, often derived from yeast or plant extracts, supporting the growth of a wide range of microorganisms.

enriched media

can support many microbes including fastidious microbes

Which of the following are components of the extracellular matrix in a biofilm? 

proteins, polysaccharides, lipids, dna

In the bacterial growth curve, what is the primary reason for the lag phase? 

adaptation of bacteria to the growth conditions

biofilm formation process

• Reversible attachment

• Irreversible attachment

• Microcolony formation

• Maturation

• Quorum sensing

• Dispersion

Which of the following statements are true about the log phase of bacterial growth? 

• Cells are most susceptible to antibiotics during this phase.

• The metabolic activity of the cells is at its peak.

  The bacterial population is doubling at a constant rate.

During which phase of the bacterial growth curve is the rate of cell division equal to the rate of cell death? 

stationary phase

Which of the following statements are true about quorum sensing? 

• It involves the production and detection of signaling molecules called autoinducers.

• It is a mechanism of cell-to-cell communication in bacteria.

• It plays a role in the detachment of cells from the biofilm.

• It regulates gene expression based on cell density.

Reversible attachment

Initial adherence of bacteria to a surface, which can easily be reversed.

Microcolony formation

Bacteria begin to divide and form small clusters.

Maturation

Formation of a three-dimensional structure with increased production of extracellular matrix.

Dispersion

Release of cells from the biofilm to colonize new areas.

catabolism

metabolic pathways

oxidation

exergonic

typically releases electrons in the form of hydrogen

anabolism

typically takes in electrons in the form of hydrogen

endergonic

reduction

phototrophs

organisms that take energy from light

chemotrophs

energy from breaking chemical bonds

organotrophs

organisms that get electrons from organic compounds

lithotrophs

electrons from inorganic compounds

autotrophs

organisms that produce their own food from carbon dioxide and energy sources like sunlight or chemical reactions.

heterotroph

organisms that obtain food by consuming other living things, relying on organic material for nutrition.

protein catabolism

amino acids can enter the cell and take part into the krebs cycleto generate energy through degradation of proteins.

nucleic acid

dna and rna

where does glycolysis occur

in the cytoplasm for both prokaryotes and eurkaryotes

what is the starting substrate for krebs/tca

acetyl coA

where does krebs cycle occur

cytoplasm of prokaryotes

mitochondria eukaryotes

what is the transition reaction

breaks down pyruvate into acetyl coA

where does transition step occur

cytoplasm of prokaryotes and mitochondria of eukaryotes

aerobic respiration

a metabolic process that requires oxygen to convert glucose into ATP, carbon dioxide, and water.

anaerobic respiration

a metabolic process that occurs without oxygen, allowing organisms to produce ATP through substrate-level phosphorylation and fermentation. inorganic molecules other than oxygen are utilized as final electron acceptors.

fermentation

Fermentation is an alternative anaerobic step that comes after Glycolysis and occurs in the cytoplasm. Therefore while fermentation itself doesn't produce ATP, glycolysis will provide the ATP. Useful products like Lactic acid and Ethanol can be produced

Pentose Phosphate Pathway

A metabolic pathway that generates NADPH and ribose 5-phosphate for nucleotide synthesis. It operates alongside glycolysis and the citric acid cycle.

cellular respiration

order of steps : glycolysis, transition, krebs etc

ETC

membrane potential and final electron acceptor

Which classification best fits a bacterium that uses organic compounds for carbon and inorganic compounds as a source of electrons?

chemoheterotroph

metanotrophs

These organisms metabolize methane as their source of carbon and chemical energy. Their oxidation of CH₄/methane results in the production of CO₂ which goes back into the atmosphere.

methanogens

are a group of microorganisms that produce methane as a metabolic byproduct in anoxic conditions, typically using carbon dioxide as a carbon source.

nitrification

the oxidation of ammonia to nitrate

ammonification

the break down of complex waste to ammonia

nitrification

the oxidation of ammonia to nitrate

denitrification

the reduction of nitrite to nitrogen gas

first step in nitrogen cycle

nitrogen fixation

second step in nitrogen cycle

ammonification

third step in nitrogen cycle

nitrification

fourth step in the nitrogen cycle

denitrification

lithotrophs and sulfur photosynthetic bacteria metabolize h2s

oxidation step

anaerobic respirators use sulfate as final electron acceptors

reduction step