I. Microscopy

• magnification

• resolving power

               

Ocular x Objective

           

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

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 only in Kingdom Monera

• found in Kingdoms Protista, Fungi, Plantae, Animalia• 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

• no membrane-bound organelles

• contains cytoplasm w/ cytosol and membrane-bound organelles• have a plasma

membrane and usually a cell wall• usually smaller than eukaryotes

PROKARYOTIC vs. EUKARYOTIC

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