I. Microscopy magnification Ocular x Objective resolving power                            

Electron Microscopes: Better resolving power than light microscopes TEM  aims an electron beam at a thin stained section Used to study internal cell structure

SEM  beam scans the surface of a specimen coated with a thin layer of gold Visualized entire image Creates a 3-D image

DENSITY BUT, EM’s can only view dead cells PHASE CONTRAST  allow unstained, living tissues to be observed CELL FRACTIONATION  using a centrifuge to separate cell components based on DENSITY

PROKARYOTIC vs. EUKARYOTIC found in Kingdoms Protista, Fungi, Plantae, Animalia found only in Kingdom Monera no true nucleus; lacks nuclear envelope true nucleus; bounded by nuclear envelope genetic material in nucleoid region genetic material within the nucleus

PROKARYOTIC vs. EUKARYOTIC contains cytoplasm w/ cytosol and membrane-bound organelles no membrane-bound organelles have a plasma membrane and usually a cell wall usually smaller than eukaryotes

PROKARYOTIC vs. EUKARYOTIC

II. PARTS of the CELL CELL SIZE is limited by: metabolic requirements surface area to volume ratio II. PARTS of the CELL

nucleus histones

cytoplasm cytosol nucleolus ribosomes endoplasmic reticulum

Golgi apparatus lysosomes intracellular digestion apoptosis

vacuoles peroxisomes

mitochondria

Cytoskeleton microtubules intermediate filaments microfilaments

cell walls

glycocalyx Intercellular Junctions tight junctions desmosomes

gap junctions

IV. MEMBRANES Singer-Nicolson Fluid Mosaic Model

Selective Permeability

Water Potential hypoosmotic environments isotonic environments hyperosmotic environments

Diffusion and Osmosis

Facilitated Diffusion                                                       Active Transport

Forms of Active Transport ATP Pump Symport Antiport

Receptor-mediated endocytosis