Bacterial and Eukaryotic Cell Structures and Processes (topic 11 and 12)

These flashcards cover the essential concepts related to the structure and functions of prokaryotic and eukaryotic cells, including gene transfer mechanisms and the endosymbiotic theory.

Bacterial Chromosomes vs. Eukaryotic Chromosomes

Bacterial chromosomes are circular and typically single; eukaryotic chromosomes are linear and found in pairs.

Plasmids

Small, circular DNA molecules found in bacteria that can carry antibiotic resistance genes or other traits.

Vertical Gene Transfer

The transmission of genetic material from parent to offspring, typically during reproduction.

Horizontal Gene Transfer

The transfer of genetic material between organisms in a manner other than traditional reproduction, including transformation, conjugation, and transduction.

Transformation

The process of genetic material uptake from the environment by a cell.

Conjugation

The transfer of genetic material between bacteria through direct contact, often involving a pilus.

Transduction

The transfer of genetic material from one bacterium to another via bacteriophages.

Nucleoids

Regions in prokaryotic cells where genetic material is located, often not membrane-bound.

Ribosomes

Molecular machines in cells that synthesize proteins by translating mRNA.

Inclusion Bodies

Cytoplasmic structures in prokaryotic cells used for storage of nutrients or other materials.

Endospores

Highly resistant structures formed by some bacteria to survive extreme conditions.

Cell Envelope

The external covering of a bacterial cell, typically consisting of the cell wall and membrane.

Slime Layer vs. Capsule

Slime layers are loosely attached and help in adhesion, while capsules are tightly bound and protect against phagocytosis.

Gram-positive Cell Wall

Thick peptidoglycan layer retaining the crystal violet stain.

Gram-negative Cell Wall

Thin peptidoglycan layer surrounded by an outer membrane; does not retain crystal violet stain.

Acid-fast Stain

A staining technique used to identify bacteria with waxy cell walls, such as Mycobacterium.

Flagellum

A long, whip-like appendage used for locomotion in bacteria.

Monotrichous Flagellation

A bacterial flagellar arrangement with a single flagellum at one end.

Amphitrichous Flagellation

A flagellar arrangement with a single flagellum at both ends.

Lophotrichous Flagellation

A flagellar arrangement with multiple flagella at one end.

Peritrichous Flagellation

A flagellar arrangement with flagella distributed over the entire surface of the cell.

Positive Chemotaxis

Movement towards a chemical attractant.

Negative Chemotaxis

Movement away from a chemical repellent.

Pilus

A hair-like appendage that enables bacteria to attach to surfaces and facilitate conjugation.

Fimbriae

Short, hair-like structures that help bacteria adhere to surfaces.

Cell Size

Cells tend to remain small to optimize nutrient uptake and waste removal.

Eukaryotic Cell Components

Eukaryotic cells contain organelles such as the nucleus, endoplasmic reticulum, and mitochondria.

Prokaryotic Cell Components

Prokaryotic cells lack membrane-bound organelles and typically have simpler structures.

Endocytosis

The process by which cells internalize substances by engulfing them in a membrane.

Exocytosis

The process of expelling materials from a cell by vesicle fusion with the plasma membrane.

Phagocytosis vs. Pinocytosis

Phagocytosis is the uptake of large particles, while pinocytosis is the uptake of liquid and small solutes.

Endosymbiotic Theory

The theory that eukaryotic organelles like chloroplasts and mitochondria originated from symbiotic prokaryotes.