Chapter 3 lecture video notes The Structure and Evolution of Prokaryotic and Eukaryotic Cells

Flashcards covering the introduction to prokaryotic and eukaryotic cell structures, including domains, morphology, cell wall composition, and organelles.

Karyote

A term that refers to the nucleus.

E u

A prefix meaning true, used in the term eukaryotes to define cells with a true nucleus.

Pro

A prefix meaning before, used in the term prokaryotes to define cells that evolved before a nucleus.

Nucleoid

The region in a prokaryotic cell where DNA is stored, which lacks a surrounding membrane.

Histones

Proteins that associate with DNA to package it within the cell; they are present in Archaea and Eukarya but absent in Bacteria.

Peptidoglycan

The material that makes up bacterial cell walls, consisting of glycans (sugars) and peptides (proteins).

Pseudo peptidoglycan (Pseudomurein)

A molecule similar to peptidoglycan that makes up the cell walls of Archaea; it lacks N-acetylmuramic acid.

Motility

The use of energy by an organism to move itself through the environment.

Flagellin

The specific protein that makes up flagella in Bacteria.

Microtubules

The type of protein that makes up flagella and cilia in Eukarya.

$70s$ Ribosomes

The size of ribosomes found in prokaryotes (Bacteria and Archaea).

$80s$ Ribosomes

The size of ribosomes found in Eukarya.

Binary fission

The prokaryotic version of cell division, as they lack a nucleus and cannot undergo mitosis.

Monomorphic

A term describing organisms that have only one shape.

Pleomorphic

A term describing organisms that can have more than one shape.

Coccus

A spherical-shaped bacterium.

Bacillus

A rod-shaped bacterium.

Vibrio

A bacterium with a bent rod shape.

Glycocalyx (Extracellular Matrix)

A sticky layer outside the cell wall, usually made of polysaccharides, used for attachment and protection.

Capsule

A highly organized glycocalyx layer that helps prevent phagocytosis and acts as a virulence factor.

Slime layer

A loosely organized glycocalyx layer.

Basal body

The part of the bacterial flagella that attaches the structure to the cell.

Hook

The part of the bacterial flagella that rotates using ATP to facilitate movement.

Monotrichus

A flagellar arrangement featuring one flagellum at one end of the cell.

Lophotrichus

A flagellar arrangement featuring two or more flagella at one end of the cell.

Amphitrichus

A flagellar arrangement where flagella are attached to both ends of the cell.

Peritrichus

A flagellar arrangement where flagella extend off the entire surface of the cell.

Taxis

Movement in response to a stimulus, such as phototaxis (light) or chemotaxis (chemicals).

Axial filaments

Motility structures found only in spirochetes that wrap around the outside of the cell and cause a corkscrew motion.

Fimbriae

Protein structures used by cells to attach to surfaces, such as the wall of the intestine.

Sex pilius

A structure used to exchange DNA from one prokaryotic cell to another through conjugation.

Osmotic lysis

The bursting of a cell due to the excessive intake of water.

Teichoic acid

A molecule in Gram-positive cell walls that bonds layers of peptidoglycan together.

Outer membrane

A phospholipid bilayer found in Gram-negative cells that provides selective permeability and resistance to chemical controls.

Lipid A

An endotoxin released from the lipopolysaccharide of Gram-negative cells when they die.

Porin

A channel or passageway through the outer membrane of Gram-negative cells that allows molecule passage.

Mycolic acid

A hydrophobic lipid found in the cell walls of Mycobacterium and Nocardia that provides resistance to chemical controls.

Amphipathic

A term describing molecules, like phospholipids, that have both hydrophilic and hydrophobic regions.

Facilitated diffusion

The movement of molecules from high to low concentration using a transport protein but no ATP.

Active transport

The movement of molecules against a concentration gradient requiring both ATP and a transport protein.

Aquaporin

A specific protein channel used to facilitate the movement of water across the plasma membrane.

Metachromatic granule

A cellular inclusion that stores phosphorus.

Magnetosome

An inclusion that stores iron oxide, used to break down hydrogen peroxide.

Endospores

Metabolically inactive, highly resistant structures produced by genera like Bacillus and Clostridium to withstand poor environmental conditions.

$9+2$ Arrangement

The specific structural arrangement of microtubules found inside eukaryotic flagella and cilia.

Endocytosis

A process in eukaryotes to bring large molecules into the cell, including phagocytosis (cell feeding) and pinocytosis (cell drinking).

Endosymbiotic Theory

The theory explaining that eukaryotes evolved from a large prokaryote ingesting smaller prokaryotes, which eventually became mitochondria and chloroplasts.