Cytology Introduction to Cells. Magnification Resolution ~ 0.2 m in LM ~ 0.2 nm in EM Magnifying Power ~ 2,000x in LM ~ 2,000,000x in EM.

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

Fractionation

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.

Plasma membrane

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