2. Cytoplasmic Membrane
3. Nucleus (Ekuaryote) or Nucleoid (Prokaryote)
5. Cell Wall
Basic Cellular Structures
Non-cellular, reproduce only inside of a host cell, and lack many characteristics of living things
"Fluid" selective permeability barrier made of phospholipids and proteins that form a bilayer with a hydrophillic exterior and hydrophobic interior
The result of the attraction of nonpolar fatty acid portions of one phospholipid layer for other layer
1. Permeability Barrier
2. Structural Support
3. Energy Conservation
Functions of the Cytoplasmic Membrane
Prevents leakage of cytoplasmic metabolites into the environment and transportation of substances (nutrients and waste products) into and out of the cell
Water and small, uncharged particles
What are the only things that can freely diffuse through the membrane due to the hydrophilic outside and hydrophobic inside?
What do Archaea use to reinforce their cytoplasmic membrane by increasing the stability at high temperatures and low pH?
N-acetylglucosamine (NAG) and N-acytelmuramic acid (NAM)
Two sugars that make up the backbone of peptidoglycan
Provides rigidity and shape to the cell and prevents it from exploding due to high pressure inside the cell
Function of Peptidoglycan
This is produced by many organisms and it cleaves the lactam ring of penicillin, inactivating the penicillin
Lack peptidoglycan so their cell walls are made of other polysaccharides such as pseudopeptidoglycan, have a paracrystalline surface layer cell wall, or have S-layers
The cell walls of Gram-positive Bacteria are reinforced by these negatively charged acids
What is found in animal secretions and is thought to be major line of defense against infections by bacteria?
Outer lipopolysaccharide (LPS) layer and inner phospholipid layer
What makes up the lipid bilayer of a Gram-Negative bacteria?
These are found within the membrane of a Gram-negative bacteria and are used in transport
Toxic portion of the lipopolysacchardie (LPS) layer of the Gram-negative bacteria. It has a toxic effect on humans and is released when the cell dies
Transmembrane proteins that allow for permeability through the outer membrane by creating channels that cross the membrane
Channels with binding sites for certain molecules that only allow those molecules to pass through
Hydrolytic enzymes and Nutrient Transporter Binding proteins
Proteins that are contained in the periplasm of a Gram-negative Bacteria
Capsule, S layer, Thick Cell wall, Thin Periplasm, and Cytoplasmic Membrane
The Gram-Positive Envelope from the outside in contains:
Part of the Gram-positive and Gram-negative envelopes that is made of a polysaccharide; not all species have it
Thick Cell Wall
Part of the Gram-positive envelope that is made of amino acids crosslinks in peptidoglycan. Contains Techoic acids for strength
Capsule, Outer Membrane, Thin Cell Wall, Thick Periplasm, and Cytoplasmic Membrane
The Gram-negative envelope from the outside in contains:
Thin Cell Wall
Part of the Gram-negative envelope that is made of amino acid crosslinks in peptidoglycan
Prokaryotes have a singular circular chromosome and sometimes circular extrachromosomal DNA called
The Bacterial Nucleoid
Single loop of double stranded DNA that is attached to the cell envelope--no membrane separtes DNA from cytoplasm
~4e6 bp in many bacteria.
A cell elongates slightly as it grows and the cytoplasm pinches in the middle at this location
This is how DNA replicates, allowing it to begin the next replication before the cell divides
Occurs at the equator of the cell so that there is an equal division and each daughter cell has the same shape
Defines the division protein plane in prokaryotes; polymerizes to form a ring where the cell division will occur
Involved in peptidoglycan synthesis for the new cell wall. Activity is blocked by penicillin
Filamentous Sprial Shaped Bands
MreB forms these bands around the inside of the cell under the cytoplasmic membrane
Coccus shaped bacteria lack this gene and therefore take on the default spherical bacteria shape
These are inserted into preexisting wall material to synthesize a new cell wall during bacterial growth
Creates openings in existing cell wall to make space for new cell wall glycans to be inserted
Autolysis (Spontaneous Cell Lysis)
May occur if there is an error in inserting new cell wall material
Hydrophobic lipid alcohol that binds N-acetylglucosamine, N-acetylmuramic acid, and pentapide peptidoglycan precursors. Helps transport these new glycan unites through CM to become part of the growing cell wall
Formation of peptide crosslinks between NAMs and bonds peptidoglycan precursors into expanding peptidoglycan layer. Reaction is inhibited by penicillin and cell lysis occurs
Prokaryotic cells often contain these granules that function as storage material or to orient the cell
Intracellular particles of magnetite that allow the organism to respond to a magnetic field
What are examples of inclusion granules?
Inclusion granule that is used as an energy source in prokaryotic cells; some gram-negative prokaryotes can store this in its elemental form in globules in the periplasm
Non-motile extensions that help bacteria attach to surfaces and to other bacteria; NOT for motility, strictly for attachment
Hollow, non-motile tubes made of protein called pilin that connect some cells. They are longer than fimbriae and shorter than flagella
Sticky polsaccharide layer surrounding the cell and helps the cell attach to objects
Ring that is located in the cytoplasm and attaches to the inner surface of the cytoplasmic membrane
What increases and prolongs the run so that the net movement of bacteria is toward the attractants?
Transport, bioenergetics, and chemotaxis
The structural support function of the cytoplasmic membrane is the sit of many proteins involved in?
Peptidoglycan (Bacterial Cell Wall)
What consists of sugar chains wrapped in circles around the cell that are linked to each other by short chains of amino acids?
Lysozome doesn't have an effect this, which is what some Archaea cell walls are made of
Under the Cytoplasmic Membrane
Where does MreB form the filamentous spiral shaped bands inside of the cell?
What helps transfer the new glycan unites through the CM to become part of the growing cell wall?
Filamentous cyanobacteria, Myxococcus, Cytophage, and Flavobacterium
What prokaryotes move by gliding motility instead of flagella?