Summary Biology: Cell Structure & Function

Ch 4 Cell Structure & Function
4.1 What is cell theory
Cell: “Basic unit of life”
Our cells differ: hair, skin
Cell  Tissue Organ
Cell theory: “All cells come from previous cells”
3 principles:
i. Every organism is made up of 1 or more cells
ii. Smallest organisms are unicellular and all cells are the functional units of
multicellular organisms
iii. All cells arise from preexisting cells


All cells:
o Perform functions
o Eliminate wastes
o Interact with cells/communicate
o Get energy


All cells have:
o Plasma membrane (not all have wall)
 Communicate with cells & environment
 Isolation (cell content)
 Regulates flow of material in & out (pourous)
o Cytoplasm: all structures & fluid within cell
 Handles cellular metabolic activities
o DNA & RNA: RNA copies DNA


Types of cells:
 Prokaryotic (bacteria & archaea)
o Unicellular
o Special surfaces but lack membrane enclosed organelles/nucleus
o DNA present (not in nucleus)

, Eukaryotic (humans)
o Nucleus
o Advanced & complex
o Organelles
o Chromatin: DNA inside nuclear membrane
o Nucleolus: inside nucleus. Synthesizes ribosomes
o Ribosomes: produce protein & travel to Rough ER
o Mitochondria: power house (cellular respiration: make energy)

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