Bio 245 Lecture 2: Archaea, Eukaryotic Structures, and Viruses

Flashcards covering the characteristics of Archaea, eukaryotic cell organelles, endosymbiotic theory, viral lifecycles, and prion-related diseases.

Archaea

Unicellular prokaryotes that lack peptidoglycan in their cell walls and possess genetic machinery more similar to eukaryotes than bacteria.

Methanogenesis

A unique metabolism found in Archaea that leads to the production of methane.

Extremophiles

Organisms, including most Archaea, that thrive in extreme physical or geochemical conditions.

Methanopyrus kandleri

An archaeon discovered on a Black Smoker with an optimum temperature of $98\,^{\circ}C$.

Methanobrevibacter ruminatum

An archaeon that produces methane and is found in the rumen of a cow.

Ether linkages

The specific chemical bonds that link isoprenoid chains to $G1P$ in archaeal cell membranes.

Archaella

An $ATP$-powered molecular propeller used for motility in Archaea.

Endosymbiotic theory

The theory that eukaryotes arose when a bacterial cell was engulfed by a larger archaeal cell, eventually becoming the mitochondria.

Alphaproteobacteria

The bacterial Class associated with mitochondrial $16S$ RNA in phylogenetic trees.

Cyanobacteria

The bacterial phylum associated with chloroplast $16S$ RNA in phylogenetic trees.

9 + 2 structure

The specific arrangement of microtubules found in eukaryotic flagella.

Cilia

Short, numerous locomotor organelles arranged in rows that beat back and forth to move a cell.

Glycocalyx

The outermost boundary of a eukaryotic cell, composed of polysaccharides, that functions in adherence, communication, and protection.

Chitin

A primary component, along with cellulose or glucans, of fungal cell walls that provides structural support.

Sterols

Lipid components within the eukaryotic phospholipid bilayer that help maintain a selectively permeable barrier.

Nucleolus

The mass at the center of the nucleus where $rRNA$ is synthesized.

Chromatin

The material that makes up chromosomes and contains the cell's genetic information.

Rough Endoplasmic Reticulum

A network of sacs embedded with ribosomes that functions in making and transporting cellular substances.

Smooth Endoplasmic Reticulum

A portion of the endoplasmic reticulum that transports molecules, synthesizes lipids, and detoxifies waste.

Golgi Apparatus

An organelle that collects, packages, and modifies proteins before transporting them to their final destination via condensing vesicles.

Mitochondria

The site of $ATP$ generation and aerobic respiration, characterized by folded membranes containing enzymes and electron acceptors.

Microfilaments

Thin strands of actin within the cytoskeleton that attach to the cell membrane.

Microtubules

Long hollow tubes that maintain the shape of cells, particularly those without cell walls.

Obligate intracellular parasites

A classification for viruses indicating they cannot survive or replicate without a host cell.

Capsid

The protein container that houses a virus's genetic material (DNA or RNA).

Bacteriophage

A virus that specifically infects bacterial cells.

Lytic lifestyle

A viral lifecycle in which the virus replicates and then splits open the host cell to release mature viruses.

Lysogenic lifestyle

A lifecycle where viral DNA remains dormant in the host DNA, known as a prophage, until induction triggers the lytic cycle.

Transduction

The process by which a phage excises from a bacterial chromosome, carrying local bacterial DNA to a new host cell.

Plaque assay

A method to culture phages using a bacterial lawn; plaques are zones of clearing that indicate viral lysis.

Prions

Infectious, misfolded proteins that cause healthy proteins to misfold upon contact.

Transmissible spongiform encephalopathy (TSE)

A degenerative brain and nervous tissue disorder, such as Mad Cow Disease, caused by prions.

Creutzfeld-Jakob Disease (CJD)

A fatal neurodegenerative disorder caused by a prion, often progressing to death within one year of symptom onset.

Chronic wasting disease (CWD)

A TSE that affects deer, elk, and moose, colloquially known as zombie deer disease.