Structure and Organization of Prokaryotic Cells

This set of flashcards covers vocabulary related to the structure and organization of prokaryotic cells, including key terms, definitions, and concepts from the lecture notes.

Prokaryote

A unicellular organism that lacks a nucleus and membrane-bound organelles.

Cell Morphology

The study of the form and structure of prokaryotic cells, which can vary significantly in shape and arrangement.

Bacillus

Rod-shaped bacterial cell.

Coccus

Sphere-shaped bacterial cell.

Spirillum

Spiral-shaped bacterial cell.

Vibrio

Spiral shaped cells

Spirochete

Spiral shaped cells

All prokaryotic cells have

-structures for sending and responding to the surrounding environment

(Pili, and/or flagella, and/or glycocalyx)

-structures to compartmentalize metabolism

(Ribosomes, inclusions)

-structures to control growth and reproduction

(DNA chromosome, plasmids)

Flagella

Long, whip-like structures that provide motility to prokaryotic cells.

Pili

Short, hair-like structures that allow bacteria to attach to surfaces and facilitate processes such as conjugation.

Glycocalyx

A sticky layer surrounding the cell wall composed of polysaccharides and proteins, serving as a protective barrier.

Ribosome

A particle composed of RNA and protein involved in manufacturing proteins

Cytoplasm

The semi fluid substance inside the cell in which much of the cells metabolism occurs

Nucleoid

The area containing the bacterial chromosome, which contains essential genes for metabolism and reproduction

Plasmid

A closed loop of DNA containing non-essential genetic information

Inclusions

Cytoplasmic sites for the storage of nutrients

Cell wall

A semi rigid structure, composed of carbohydrate and protein, providing shape and structural support

Cell membrane

A lipid ball layer with proteins, controlling the movement of materials into and from the environment

Peptidoglycan

A polymer that makes up the cell wall of bacteria, providing structural integrity.

Gram-Positive Cell Wall

Characterized by a thick peptidoglycan layer, making it a target for certain antibiotics.

Gram-Negative Cell Wall

Characterized by a thin peptidoglycan layer and an outer membrane, often more resistant to antibiotics.

Nucleoid

The region in prokaryotic cells where the chromosome is located, not surrounded by a membrane.

Plasmid

Small, circular, double-stranded DNA molecules independent of chromosomal DNA, often containing genes for antibiotic resistance.

Ribosomes

Cellular structures responsible for protein synthesis, made up of RNA and proteins.

Facilitated Diffusion

The process of passive transport of molecules across a membrane via a specific transporter.

Active Transport

The movement of molecules against their concentration gradient, requiring energy from ATP.

Cytoplasm

The semi-fluid matrix inside the cell membrane, containing the nucleoid, ribosomes, and other structures.

Cytoskeleton

A network of protein filaments in prokaryotic cells that helps maintain cell shape and assists in cell division.

Taxonomy

The science dealing with the systematized arrange arrangements (classification) of related living things in categories

Classification

The arrangement of organisms into hierarchy groups based on relatedness

Taxon

Species. The least inclusive, most fundamental rank.

Family

a taxon (category) of related organisms, consisting of one or more genera

Order

A taxon (category) of related organisms, consisting of one or more families

Class

A taxon (category) of related organisms, consisting of one or more orders

Phylum

Barry’s classes comprise this

Tree of life (TOL)

A depiction for the evolution of life and the relationships between organisms

Morphology

Structure and shape

Flagellum in ____, archaellum in ____.

Bacteria; archaea

Flagella have three subunits

Helical filament

Hook

Basal body

Cell motility (run):

Counterclockwise rotation. Propels the bacterial cell forward

Cell motility (tumble):

Clockwise rotation. Cell randomly moves in space and changes direction.

Cell motility (chemotaxis):

Chemical attractants length and runs as cell moves toward nutrients

Glycocalyx

Is a sticky layer of polysaccharides and small proteins secreted to surround the cell wall

Glycocalyx comes in two forms

Capsule (thick firmly bound to sell. Can be seen by negative stain or TEM) and slime layer (thin, water-soluble layer)

Cell envelope

Cell wall and cell membrane

The primary structural component of a cell wall

Peptidoglycan

Peptidoglycan is found in ____, not ____

Bacteria; archaea

Gram-positive cell walls are

Very thick peptidoglycan layer

Gram-negative cell wall walls are

thin, peptidoglycan layer

Two types of membrane proteins

Integral proteins

Peripheral proteins