Eukaryotic cells have organelles Eukaryotic Cells Eukaryotes differ

Eukaryotic cells have organelles.

Eukaryotic Cells • Eukaryotes differ from prokaryotes in several ways: 1) separation of nucleus from cytoplasm by double membrane (nuclear envelope) 2) DNA organized into distinct chromosomes (X-shaped) 3) complex membrane-bound organelles (e. g. , mitochondria)

Three Functional Categories of Eukaryotic Organelles 1) Manufacturing Nucleus – genetic control center - DNA & RNA synthesis and ribosome assemble ribosomes: assemble amino acids into polypeptides (proteins/enzymes)

Three Functional Categories of Eukaryotic Organelles 1) Manufacturing Rough Endoplasmic Reticulum (Rough ER) - network of interconnected membranebound sacs - “rough” appearance because ribosomes stuck to membrane surface

Three Functional Categories of Eukaryotic Organelles 1) Manufacturing Golgi Apparatus (GA) “cell’s warehouse/factory” - stacks of membrane-bound sacs - work in close association with ER - receive, store, modify products of ER

Three Functional Categories of Eukaryotic Organelles 2) Breakdown of Material Lysosomes - produced by Rough ER & GA - digest nutrients within cell Vacuoles - plant cells - digest nutrients & storage sac

Three Functional Categories of Eukaryotic Organelles 3) Energy Processing Chloroplasts - plant cells - site of photosynthesis - absorb sun light & transform this energy to food - light absorbed in grana (stacked “solar packs”)

Three Functional Categories of Eukaryotic Organelles 3) Energy Processing Mitochondria – “cell powerhouse” - cellular respiration - double membrane - folds (cristae) of inner membrane - matrix is the inner fluid

Advantages of membrane-bound organelles • 1. compartments • 2. unique chemistry in different compartments • 3. membranes themselves have enzymes embedded) • 4. provides localized environment

Advantages of membrane-bound organelles • 1. compartments • 2. unique chemistry in different compartments • 3. membranes themselves have enzymes embedded) • 4. provides localized environment

Origin of Eukaryotic Cells from Prokaryotes – Additional Evidence Supporting the Endosymbiotic Hypothesis • 1. Mitochondria and Chloroplasts contain DNA and ribosomes similar to bacteria • 2. Double membrane • 3. Circular DNA • 4. Looks like bacteria • 5. Reproduces by binary fission

Road to Modern Organisms 1 st life was bacteria unicellular prokaryotes Photosynthesis changed Earth’s atmosphere released O 2 - cyanobacteria!!!! 2 nd was unicellular eukaryotes Endosymbiotic Theory 3 rd was multicellular organisms

Origin of Eukaryotic cells • The endosymbiotic theory is a theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms