Two Fundamentally Different Classes of Cells charcteristic Prokaryotic Cells
Eukaryotic Cells word origins pro=before karyon=kernel or nucleus eu=true karyon=kernel or nucleus
Domains of Bacteria
1. archaea or archaebacteria, more ancient in soil and water also in hostile environments, many without oxygen high salt/brine methanogens halophiles thermoacidophiles hot acidic springs
2. bacteria or eubacteria, more recent, very different biochemistry from archaea regular bacteria in soil, water, pathogens cyanobacteria
Animal
Plant
Fungi
Protist origins first to appear in the fossil record, not physically changed today most likely evolved from prokaryotes
SIMILARITIES
building blocks carbon compounds amino acids, nucleotides, fatty acids, monosaccharides
Functioning units proteins, nucleic acids, lipids, carbohydrates information storage info expression
DNA, use the same language, genes
RNA, information transfer, same language
Protein prduction
Proteins are made the same way - by the ribosome metabolism use many of the same biochemical pathways
Cellular boundary plasma membrane
Cell wall ridgidity, cellular protection peptidoglycan; composed of carbohydrates and peptides plants, ridgidity, cellular protection
(not in animal cells) cellulose, carbohydrates
DIFFERENCES
Prokaryotes
Eukaryotes size Small, few microns
Large, average cell is 5-20 m, frog egg is 1mm
~10 times the length
~1000 times the volume nuclear region nucleoid, poorly demarcated region of the cell where the DNA is located not bounded by membrane nucleus, bounded by the nuclear membrane or nuclear envelope gene structure no introns introns transcription and translation occur simultaneously for each transcript no RNA processing one RNA polymerase occurs at different times and different places in the cell
RNA is processed three RNA