Cytology
Introduction to Cells
MagnificationResolution
~ 0.2 mm in LM
~ 0.2 nm in EM
Magnifying Power~ 2,000x in LM
~ 2,000,000x in EM
Electron MicroscopesTransmission EM
Internal features
Scanning EMSurface features
EM DrawbacksExpense
B&W Images
Dead specimens
Why are cellsso small?
VolumeThe need to acquire nutrients and dispose of waste is the same with one large or many small cells.
Surface AreaThe ability to acquire nutrients and dispose of waste is six times greater w/ small cells.
DNA FunctionNuclear envelope (+ pores)
Nucleolus
Chromosomes and chromatin
TranscriptionDNA mRNA
Protein SynthesisTranslation
mRNA polypeptide
ER FunctionLipid synthesis
Protein modification
Drug detox
Golgi ApparatusProtein modification
Packaging for export
Lysosomes Intracellular digestion Autophagy
MitochondriaCellular Respiration (Food ATP)
DNA + Ribosomes + division + membranes
Chloroplasts
Photosynthesis (Light Food)
DNA + Ribosomes + division + membranes
VacuolesMembrane sacs
Food vacuole
Contractile vacuolePumps excess water out of cells