Notes for BIO1140
TOPIC 1- INTRO TO CELL BIOLOGY
Cell Theory:
1) all organisms consist of one or more cells
2) the cell is the basic unit of structure for all organisms (Theodor Schwann)
3) all cells arise only from pre-existing cells (i.e cell= basic unit of reproduction) (Rudolf Virchow)
Cells have enormous diversity (function and size), but have unity (similar basic chemistry i.e DNA, ATP, metabolism, etc.)
** units: 1µm= 10-6m, 1nm= 10-9 m (typical prokaryote is 1-5µm, typical eukaryote is 10-30 µm) ribosome diameter= 30 nm, nucleus diameter= 0.006mm, mitochondrion length=3x10-6m, giraffe axon length= 1m, microfilament diameter=0.007µm
Main limitations of cell size are need to maintain an adequate SA:V ratio, to keep diffusion distances small, and to maintain adequate concentrations of substances. Cells with small SA and large V would not be able to get proper nutrients/ exchange with environment. Eukaryotes can be larger because their organelles can support larger volumes.
Prokaryotes: simple structure (cell wall, cytoplasm, plasma membrane, ribosomes, nucleoid, flagellum, lacks organelles), DNA is circular and single chromosome. (ex.= bacteria)
Eukaryotes: multicellular (protists, fungi, animals, plants) use compartmentalization of cellular functions and transport systems (cytoskeleton) to accommodate size.
** Similarities btwn eukaryote and prokaryote: plasma membrane, electron transport chain, transcription/ translation machinery (relies on ribosomes)
Organelles
Cytoskeleton (non membrane bound)
Support/shape, internal organization, movement of cell/ movement within cell. Microfilaments, microtubules, intermediate filaments
Ribosomes (non membrane bound)
Protein synthesis, catalyzes RNA reactions
Nucleus (membrane bound) nuclear envelope, nuclear pores, nucleolus, DNA/ proteins organized into chromosomes/ chromatin
Endoplasmic Reticulum (membrane bound)
Tubular membranes and cisternae, Rough= works with ribosomes on protein synthesis, Smooth=
Cell Theory:
1) all organisms consist of one or more cells
2) the cell is the basic unit of structure for all organisms (Theodor Schwann)
3) all cells arise only from pre-existing cells (i.e cell= basic unit of reproduction) (Rudolf Virchow)
Cells have enormous diversity (function and size), but have unity (similar basic chemistry i.e DNA, ATP, metabolism, etc.)
** units: 1µm= 10-6m, 1nm= 10-9 m (typical prokaryote is 1-5µm, typical eukaryote is 10-30 µm) ribosome diameter= 30 nm, nucleus diameter= 0.006mm, mitochondrion length=3x10-6m, giraffe axon length= 1m, microfilament diameter=0.007µm
Main limitations of cell size are need to maintain an adequate SA:V ratio, to keep diffusion distances small, and to maintain adequate concentrations of substances. Cells with small SA and large V would not be able to get proper nutrients/ exchange with environment. Eukaryotes can be larger because their organelles can support larger volumes.
Prokaryotes: simple structure (cell wall, cytoplasm, plasma membrane, ribosomes, nucleoid, flagellum, lacks organelles), DNA is circular and single chromosome. (ex.= bacteria)
Eukaryotes: multicellular (protists, fungi, animals, plants) use compartmentalization of cellular functions and transport systems (cytoskeleton) to accommodate size.
** Similarities btwn eukaryote and prokaryote: plasma membrane, electron transport chain, transcription/ translation machinery (relies on ribosomes)
Organelles
Cytoskeleton (non membrane bound)
Support/shape, internal organization, movement of cell/ movement within cell. Microfilaments, microtubules, intermediate filaments
Ribosomes (non membrane bound)
Protein synthesis, catalyzes RNA reactions
Nucleus (membrane bound) nuclear envelope, nuclear pores, nucleolus, DNA/ proteins organized into chromosomes/ chromatin
Endoplasmic Reticulum (membrane bound)
Tubular membranes and cisternae, Rough= works with ribosomes on protein synthesis, Smooth=