11.08.11+-+Cellular+Organelles

Cellular Organelles


 * 1. Understand general concepts of cellular organization and modern tools with which to study it.**

Cytoplasm is densely packed.


 * 2. Understand evolutionary origins of different cellular compartments.**

Invagination (e.g. golgi, ER, nucleus envelope) Engulfment (e.g. mitochondria)


 * 3. Understand how cellular organelles are identified and classified.**

The evolutionary origin of the organelle determines the nature of the organelle and the membrane surrounding it. This is how organelles are identified and classified, either by their membrane or evolutionary origin.


 * 4. Understand advantages and cost of eukaryotic cellular compartmentation.**

Two sides of the same coin. Efficiency is increased by colocalizing multiple steps of biochemical processes and by cells specializing in one or another function. This efficiency takes energy to maintain.


 * 5. Understand basic mechanisms of transport within and between organelles**

Gated transport between contiguous compartments: simple diffusion limited by nucleus pore size: nucleus <--> cytosol Translocation across lipid membranes: membrane imbedded channels allow molecules to overcome energy barrier to cross lipid bilayer: ER, mitochondria <--> cytosol Vesicular transport between compartments: membrane vesicles bud off and travel to destination: ER -> Golgi -> cell surface


 * 6. Know the general architecture and key functions of major eukaryotic cell organelles**

Nucleus: DNA: cell growth and reproduction ER: Continuous with outer membrane of nucleus: RER: Protein, SER: carbohydrate and lipid synthesis Golgi complex: stack of flattened sacks: Modification of proteins received from RER, buds off secretory vesicles Mitochondria: Double membrane, near energy requiring structures: cellular respiration Endosomes/Lysosomes: Bag o' enzymes: Protein internalization, recycling Peroxisomes: Bag o' crystalline enzymes: Oxidation