Micro unit 1

AHHHHHHH

Role and impact of Microbes

Microbes are normally too small to see with the naked eye, they inhabit almost every environment that supports life. They can be mutualists, commensals, or pathogens and are used in biotech, food productions, agriculture, and more

Zoonotic disease

Is a disease that is transmitted from animals to humans through direct contact, bites, or consumption of contaminated food or water. Examples are salmonellosis, the plague, and rabies.

Mircroniome

A community of microorganisms associated with a particular environment, influencing health and disease.

Pathogen

a microbe capable of causing disease

Opportunistic pathogens

a microbe that can cause a disease when an opportunity conditions allows it. These conditions may include a weakened immune system or disruption of normal flora.

Infectious disease

caused by microbes.

noninfectious disease

not caused by microbes,

communicable disease

can be transmitted between individuals through direct or indirect contact.

Noncommunicable disease

is not transmitted between individuals

Helicobacter pylori (H. pylori)

causes stomach ulcers and can lead to stomach cancer

Prokaryotes

include bacteria and archaea. they lack membrane bound organelles like a nucleus, mitochondria and chloroplasts

Eukaryotes

include plants, animals, protozoa/alge, and fungi, their DNA is enclosed in a membrane bound nucleus, and they contain membrane bound organelles.

How bacteria/archaea are defined

A polyphasic approach is used. The genomic gold standard is average nucleotide identity (ANI): about ≥95–96% ANI indicates the same species. Single-gene sequencing such as 16S rRNA can provide tentative identification; ≥97% identity is used in the lecture. Phenotypic traits and ecological niche also contribute, but phenotype alone cannot identify a prokaryotic species.

strain

is a genetically distinct version of a species that has a knew phenotype, strains can differ in a viability to cause disease or resistance to antibiotics.

Serotype/serovar

is a distinguished by specific surface antigens like O and H antigens. Serotypes are important for categorizing pathogens based on immune responses.

bacteria

prokaryotic and cellular

archaea

prokaryotic and cellular

Fungi

eukaryotic and cellular; include unicellular years and multicellular molds

Protist/algae

eukaryotic and cellular; can be unicellular or multicellular, often photosynthetic organisms.

Can morphology distinguish Archaea from Bacteria?

No. Bacteria and Archaea cannot be reliably distinguished from one another based only on physical morphology. Morphology can narrow possibilities, but it cannot identify a prokaryotic species by itself.

How can bacterial cells be distinguished from yeast by morphology?

A bacterial cell is prokaryotic and generally much smaller and lacks the membrane-bound organelles characteristic of yeast. Yeast is a eukaryotic fungus and is generally larger. Morphology can help distinguish broad groups, but morphology alone is not sufficient for species identification.

DNA replication vs. transcription vs. translation

Replication copies DNA to produce a genome copy for cell growth/division and is catalyzed by DNA polymerase. Transcription makes RNA from DNA and is catalyzed by RNA polymerase. Translation uses the RNA instructions to make protein and is catalyzed by the ribosome.

Hydrophilic

likes water

hydrophobic

repels water

polar molecules

have an uneven charge disruption

Non-polar molecules

do not have an uneven charge

Amphipathic molecules

have both hydrophilic (polar) and hydrophobic (non-polar) regions

Solute

Substance that dissolves

Solvent

substance doing dissolving

Solution

A mixture where a solute is dissolved in a solvent

pH

Acid increases H+ concentration adn have a lower pH. Base decreases H+ concentration and have a high pH value

Iconic Bonds

involve attraction between oppositely charged ions

Covalent bonds

involve sharing elections

Cell Morphology

Cell shape and arrangement, it can narrow down possibilities and help classify bacteria, but cannot identify a prokaryotic species

Diplo

pairs

strepto

chains

Tetrad

groups of four in a square

Staphylo

grape clusters

Cell membrane

Is a barrier surrounding the cytoplasm it provides selective permeability, maintains chemical gradients, and anchors structures like the flagella, in in Bacteria/Archaea is the site of ATP production during cell respiration. It contains phospholipids, proteins, and in some cells, hopanoids or sterols.

Bacteria and Eukarya

They have a similar phospholipids, an ester link, fatty acids