Prokaryotes New

Prokaryotes are

unicellular, lacks membrane bound nucleus and organisms

Monomorphic

bacteria has 1 shape

Pleomorphic

bacteria can take on different forms

What are the 2 types of Prokaryotes?

Archaea and Bacteria

Mycoplasma

tiny species of bacteria

Thiomargarita Namibiensis

the largest species of bacteria

How are nutrients obtained?

diffusion

Coccobacilli

ovoid

Spirochetes

spiral shaped with corkscrew motion

Diplococci

paired cocci

Streptococci

chains of cocci

Diplobacilli

paired bacilli

Palisade

clusters of bacilli

How do Prokaryotes reproduce?

asexually through binary fission to create clones

What is the 1st step of binary fission?

DNA is copied

What is the 2nd step of binary fission?

cell grows

What is the 3rd step of binary fission?

copied chromosomes is drawn to opposite ends of the cell

What is the 4th step of binary fission?

Septum begins to form at the midpoint

What is the 5th step of binary fission?

septum eventually walls off the resulting 2 daughter cells from one another

Extracellular Structure

structure outside the plasma membrane

Intracellular Structure

structures that lie within the boundary defined by the plasma membrane

Lipid Bilayer

a fluid mosaic where lipids and proteins move around

Why is membrane fluidity essential for function?

allows proteins to relocate where they’re needed

What are the functions of membrane proteins?

transportation, anchors, receptors, enzymes

What is allowed inside a selective permeable plasma membrane?

gases, water, small noncharged substances

What do larger ions and polar substances need to enter a selectively permeable membrane?

protein transporters

How does temperature affect the fluidity of the membrane?

warmer temperature increases fluidity and colder temperature decreases fluidity

How does unsaturated fatty acids affect the membranes fluidity?

acids prevents tight packaging and improves fluidity in the cold

How does saturated fatty acids affect the membranes fluidity?

acid tight packed with a bilayer and become more rigid in the cold

What does the structure of the phospholipid fatty acid look like for bacteria?

linear fatty acid

What does the structure of the phospholipid fatty acid look like for archaea?

long branched fatty acids

What is bacteria’s cell wall made of?

peptidoglycan

What is archaea’s cell wall made of?

pseudopeptidoglycan

Gram negative

thin peptidoglycan, periplasmic space, outer membrane

Gram positive

thick peptidoglycan, no outer membrane, harder to kill

What do protein channels form

pores

Porins

protein channels

What does Acid Fast staining detect?

Mycolic acid in cell walls

Does Mycoplasma Bacteria have a cell wall?

No

What are L-Forms?

bacteria that had a cell wall but lost it

Passive Transport

no energy investment

Diffusion

when a substance moves from high concentration to low concentration

Simple Diffusion

small noncharged molecules, gases, and lipid soluble substances enter and exit cells

Facilitated Diffusion

moves substances along their concentration gradient with help of membrane proteins

Osmosis

diffusion of water across a membrane

Osmotic pressure

the force of water against a membrane

Isotonic environment

equal amount of concentration

Hypotonic environment

lower concentration of particles with high amount of water

Hypertonic environment

higher concentration of particles with low concentration of water

Active transport

requires energy investment and transports proteins

Primary Active transport

ATP fuels transportation of substances against their concentration flow

Secondary Active Transport

uses ion gradient to drive transport with a coupled transport

Symport

same direction

Antiport

opposite direction

Phosphotransferase System

high energy phosphate transferred from a substance onto the substance being transported

Flagella

transportation

What are prokaryotic flagella made of?

flagellin

Run and Tumble System

allows cells to sense its environment and change directions

Chemotaxis

movement in response to chemical stimulus

Phototaxis

movement in response to light

Aerotaxis

movement in response to oxygen levels

Monotrichous

single flagella

Lophotrichous

cluster of flagella at one pole

Amphitrichous

flagella at both poles

Peritrichous

flagella all over the cell surface

Periplasmic Flagella

allows spirochetes to move

Fimbriae

adhesive

Hami

used for attachment and biofilm formation

Pili

adheres between 2 cells in order to transfer DNA

Glycocalyx

invisibility against immune system

Slime layer

unorganized-loose

Capsule

well organized-tight

Inclusions

storage

50S unit

large subunit

30S unit

small subunit

Endospores

inactive, dormant structures until stable conditions

Sporulation

process of forming an endospore

Why are gram-negative bacteria considered more virulent than gram-positive bacteria?

Their endotoxins, found in lipid A, trigger strong immune responses

How do archaea's monolayer membranes provide an evolutionary advantage?

It balances water movement across the membrane to maintain turgor pressure.

Why do gram-positive bacteria retain the crystal violet dye during Gram staining?

Their peptidoglycan layer is thick and traps the dye

How does facilitated diffusion differ from simple diffusion in bacterial membranes?

Facilitated diffusion requires transport proteins to assist in molecule movement

How does peptidoglycan protect bacterial cells

By providing structural rigidity against osmotic pressure

How does the cytoplasm support prokaryotic cellular function?

By serving as a site for all metabolic processes

How do archaea's monolayer membranes provide an evolutionary advantage?

They prevent the membrane from melting in extreme heat

Why do bacterial endospores survive extreme conditions?

Their thick protective layers shield genetic material

How does the lipid composition of archaea membranes enable survival in extreme conditions?

Their branched phospholipids form monolayers resistant to high temperatures

How does the absence of a nucleus in prokaryotes impact their genetic processes?

It requires DNA replication and transcription to occur in the cytoplasm.

Why do hypertonic environments cause plasmolysis in bacterial cells?

The high solute concentration outside draws water out of the cell

How do mycobacteria resist antibiotics and environmental stresses?

By producing a waxy layer of mycolic acid.