Cells

The smallest living unit

Two Basic Types

l  Prokaryotes – before nucleus

n     Archae

n     Bacteria

n     Size

l  Eukaryotes – true nucleus

n     Much variety

The Prokaryote Cell

Prokaryotes External Structure

l  Glycocalyx

n     Capsule

n     Slime layer

Prokaryotes External Structure

l  Flagella - flagellin

n     Arrangement

l Monotrichous, Amphitrichous, Lophotrichous, Peritrichous, Atrichous

n     Hook, filament & basal body

n     Chemotaxis

n     Spirochetes endoflagella/axial filaments

Prokaryotes External Structure

l  Fimbriae – gram negative bacteria

n     Biofilms

l  Pili

n     Conjugation

n     Attachment

 

Prokaryote – Cell wall

l   Porous

l   Outside of cell membrane

l   Peptidoglycan (murein)

n     Large Polymer

n     Tetrapeptide chain

n     Sugar backbone: N-acetylmuramic acid & N-acetylglucosamine

n     Peptide bond cross link

Types of Cell Walls

l   Gram positive

n     Thick Peptidoglycan layer

n     Teichoic and lipoteichoic acids

n     Acid Fast – mycolic acids

l   Gram negative

n     Lipopolysaccharides

l Lipid A endotoxin

n     Periplasmic space

l   Archael Cell Walls

l   Lack of cell wall

Cytoplasmic membrane

l  Fluid Mosaic Model

n     Phospholipids

n     Proteins

l Glycoproteins

n     Electrochemical gradient

l  Functions

Movement across the membrane

l  Passive

n     Diffusion

l Facilitated diffusion

l Osmosis

n    Isotonic, Hypotonic, Hypertonic

l  Active

n     Gates –port, antiports, synports

l  Both active & passive

n     Group Translocation

Prokaryotes – internal features

l  Cytosol

l  Inclusions

l  Ribosome

l  Nucleoid

l  Cytoskeleton

l  Endospores

Eukaryotic cell

Eukaryotes – external features

l   Glycocalyx

l   Flagella – tubulin

n     Membrane covered

l   Cilia

l   Cell walls – cellulose & chitin

l   Cytoplasmic Membranes

n     Sterols

n     Endocytosis

l Pseudopodia – phagocytosis

l Pinocytosis

n     Exocytosis

Eukaryotes – internal features

l  Non-membranous organelles

n     Ribosomes

n     Cytoskeleton

l Microfilaments

l Intermediate filaments

l Microtubules

n     Centrioles and centrosomes

Eukaryotes – internal features

l   Membranous organelles

n     Nucleus

l Nucleolus

l Nucleoplasm

l Nuclear envelope

l Nuclear pores

l Chromatin

l Chromosomes

l Histones

n     Endoplasmic reticulum

l Rough

l Smooth

Eukaryotes – internal features

l  Membranous organelles

n     Golgi body

l Vesicles

l Lysosomes

l Vacuoles

l Peroxisomes

n     Mitochondrion

l Cristae

n     Chloroplast

l  Endosymbiotic theory

 

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