Archaea & Bacteria - Video Notes Flashcards

Flashcards covering key concepts from the Archaea & Bacteria lecture notes: domains and basic differences, archaeal extremophiles, major archaeal groups (methanogens, halophiles, thermophiles, acidophiles), Eubacteria features, bacterial cell structure and shapes, reproduction modes, genetic recombination methods, and study quiz facts.

What are the two prokaryotic kingdoms?

Archaea and Bacteria.

What cellular feature do Archaea and Bacteria share?

Both lack distinct nuclei and have circular DNA located in the nucleoid or diffused in the cytoplasm.

How is the archaeal cell wall described in the notes?

Made of glycoproteins and polysaccharides; no peptidoglycan.

What does the term 'Archaea' signify?

Ancient.

List the shapes commonly seen in Archaea.

Spherical, rod, disc, triangle, spiral, and lobed.

How do Archaea reproduce?

Binary fission, multiple fission, fragmentation, and budding.

Who discovered Archaea and when?

Carl Woese and George Fox (1977).

What term describes Archaea that live in harsh environments?

Extremophiles.

What does the suffix '-phile' mean?

Lover of (used to describe extremophiles as 'lover of extreme').

What are methanogens?

Archaea that are obligate anaerobes, produce methane gas, and live in marshes, sediments, and digestive tracts; chemotrophic.

Give examples of methanogens.

Methanococcus; Methanopyrus.

What are halophiles and where do they live?

Archaea that thrive in salt-rich environments; live in salt lakes and salterns; photosynthetic via bacteriorhodopsin.

What are thermophiles?

Archaea living in extremely hot environments (over 100°C); found in hot springs, geysers, and hydrothermal vents; chemosynthetic; sulfur metabolism.

What are acidophiles?

Archaea that thrive in highly acidic environments (pH 1–5); found in sulfuric hot springs, acid pools, and acid mine drainage; examples Acidianus, Desulfurococcus.

What are Eubacteria?

Unicellular prokaryotes with cell walls; inhabit diverse environments (soil, water, glaciers, digestive tracts); include pathogens such as Staphylococcus aureus.

What are the main bacterial cell components?

Capsule, cell wall, plasma membrane, cytoplasm, nucleoid, ribosomes, flagellum, and pili.

Where is chromosomal DNA localized in bacteria?

In the nucleoid region.

What is the function of ribosomes in bacteria?

To make proteins.

What is the Capsule and its function?

Protects from harm, stores nutrients, removes waste; composed of polypeptide and polysaccharides.

What is the cell wall's function and composition?

Gives shape and strength; prevents bursting; composed of peptidoglycan.

What is the plasma membrane's function?

Controls what goes in and out of the cell; composed mainly of carbohydrates, proteins, and lipids.

What is the cytoplasm?

Jelly-like fluid where cell activities happen; composed of about 80% water.

What is the nucleoid?

Holds genetic material and controls cell functions.

What are the three basic bacterial shapes?

Coccus (spherical), Bacillus (rod-shaped), Spirillum (spiral).

What is a coccus?

Spherical bacteria.

What is a bacillus?

Rod-shaped (cigar-shaped) bacteria.

What is a spirillum?

Rigid, spiral-shaped bacteria with external flagella.

What is a spirochete?

Spiral-shaped bacteria with internal flagella; flexible.

What is a Vibrio?

Comma-shaped, often a facultative anaerobe.

What is a diplococcus?

Pair of cocci.

What is a streptococcus?

Chain of cocci.

What is a Staphylococcus?

Grape-like cluster of cocci.

What is a tetrad?

Group of four cocci.

What is a Sarcina?

Group of eight cocci.

What is binary fission?

The most common form of asexual reproduction; parent divides into two daughter cells; very fast (under 30 minutes).

What is spore formation?

Bacteria form spores to survive harsh conditions; examples Bacillus and Clostridium.

What is bud formation?

A small bulge forms on the side of the parent cell; grows and separates to become a new bacterium (Caulobacter and Stella).

What is cyst formation?

Thick-walled resting cells that survive tough conditions (Azotobacter and Myxococcus).

What are the three main methods of genetic recombination in bacteria?

Transformation, Transduction, Conjugation.

What is transformation?

Bacteria take in free DNA from their surroundings.

What is transduction?

A bacteriophage carries DNA from one bacterium to another.

What is conjugation?

Two bacteria connect using a sex pilus, and DNA is transferred from one to the other.

What is the role of the sex pilus in conjugation?

Connects two bacteria to transfer DNA.

Which statement about Archaea and extreme environments is true?

Archaea can live in boiling hot springs, in acidic conditions, and in highly salty environments.

What does the notes say about bacteria in space?

Some bacteria can survive in space without protection for years.

How do the bacterial and human cell counts compare in the body?

Our body has more bacterial cells than human cells.

What is a notable capability of some bacteria regarding waste?

Some bacteria can eat oil, plastic, or radioactive waste.

Who discovered Archaea and in what year?

Carl Woese and George Fox (1977).

What is the term used for Archaea that thrive in extreme environments?

Extremophiles (Archaea).