Download Cell Anatomy

Cell Anatomy
Cell
• Basic unit of living
organisms
• ~60% water
• Bathed in interstitial
fluid (external)
• Vary in shape and
function
• 3 main regions
– Nucleus, plasma
membrane, cytoplasm
• Control center,
contains genes
• 3 regions
Nucleus
– Nuclear envelope
• Double membrane
– Nucleoli
• Site of ribosome
assembly
– Chromatin
• Genetic material
• Condenses to form
chromosomes during
cell division
Plasma Membrane
• Barrier between cell contents and environment
• Lipid bi-layer, cholesterol, proteins
– Assembled tail to tail
• Head – hydrophilic
• Tail- hydrophobic
• Selective permeability
Plasma Membrane Specialized Parts
• Microvilli
– Folds, increase surface
area
• Membrane junctions
– Tight junctions
• Connect cells in sheets
– Desmosomes
• Anchor, prevents pulling
apart
– Gap junctions
• Communication
Cytoplasm
• Internal cellular material
• Contains three elements
– Cytosol
• Fluid that suspends the other elements
– Inclusions
• Stored products/nutrients
– Organelles
• Metabolic machinery
Cell Organelles
• Mitochondria – site of ATP generation
• Ribosomes – site of protein synthesis
• Endoplasmic reticulum – fluid filed tubules
– Rough ER – studded with ribosomes
– Smooth ER – lipid metabolism, detoxification
• Golgi apparatus- flattened stack of sacs,
modifies and packages
• Lysosomes – cell demolition site
• Peroxisomes – detoxifies poisons and reactive
chemicals
Cell Organelles
• Cytoskeleton - Internal framework
– Composed of
• Intermediate filaments – resist forces
• Microfilaments – cell motility, shape changes
• Microtubules – determine shape, organelle
distribution
• Cell projections
– Cillia – hair like appendages
– Flagella – long projections, motility
Cell diversity
• Over 200 types in the human body
• All vary in shape and function
• Specialized
– Connect
– Cover
– Move
– Storage
– Fight disease
– Control/information gathering
– Reproductive
Cell diversity