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Cell theory
1850's - virchow,schwann,schveiden = concepts of cell theory.
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concepts of cell theory:
- all living things are made of cells
- cells smallest living unit
- come from other cells
- chemical reactions
- heredity material
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cork cells in oak bark:
robert hooke 1665
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van leeuwenhoek:
early 1600's
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Prokaryotes:
- bacteria
- genetic info not in nucleus (in nucleoid)
- simple, no membrane bound organelles
- *person living in log cabin w/ one room)
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Eukaryotes:
- multicellular organisms
- genetic info in nucleus
- chromosomes
- DNA and protein
- membrane bound organelles
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Microscopes:
- resolve objects (resolution)
- ability to tell apart 2 objects that are close together
- Human eye: .1mm
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light microscope:
- .2um
- stain to be more visible
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electron microscope
- use tv screens to view
- use magnets to control electrons
- 1)transmission EM's .2nm
- 2)scanning EM's
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plasma membrane:
- cell membrane
- phospholipids and proteins
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cytoplasm
material inside, minus nucleus
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Location of genetic info:
- euk: nucleus
- pro: nucleoid
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ribosomes:
"protein factories"
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Nucleus:
- genetic info
- cell activites controlled
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Nuclear pore:
- in and out of nucleus
- -chromosomes (protein and dna = chromatin)
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Nucleolus
- RNA synthesis
- wound up- nucleousomes
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ER:
- endoplasmic reticulum
- -membranes (tubes.sac)
- surface to hold ribosomes
- make lipids and carbohydrates
- divide up cytoplasm into chambers
- channeling chemicals
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Kinds of ER:
- Rough: ribosomes on surface
- Smooth: no ribosomes (makes lipids/carbs)
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Ribosomes:
- protein factories - "tiny structures"
- RNA and protein
- Location: on rough ER or free in cytoplasm
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Golgi body:
- package, store, send off molecules *UPS store
- -incoming transport comes from ER
- Transport vesicle--->
- Chemically modified---> sugar + protein = clyco protein
- Secretory vesicle----<
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Glycoproteins:
cell identity (self or non self)
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Glycolipids:
Tissue identity
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Cell junctions: "communication or attachment"
- Tight -
- desmosomes-
- plasmodesmata - in plants (communication btwn cells)
- gap junction - communication
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Membrane structure:
- lipids 40-50% "phospholipids" tails non polar and face center (polar)
- proteins 50-60%
- Glycolipids + glycoproteins = glycocalyic
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Fluid mosaic model:
- proteins / lipids move freely
- proteins float on or in lipid bilayer
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Membrane proteins / function
- Function:
- transport
- enzymes
- cell surface reception of message
- indentity molecules
- cell adhesion
- attach to cytoplasm
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Membrane transport: Diffusion
- movement of molecules froma an area of higher concentration to an area of lower.
- Direct diffusion: 02 from blood to lungs, C02 to lungs.
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Membrane transport: osmosis
- diffusion of H20 molecules through a differentially permeable membrane.
- -little pores= channels "aqua porins" how H20 moves in
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Osmotyl concentration
All solutes
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isotonic / hypertonic / hypotonic
- iso - equal
- hyper - more than
- hypo - less than
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Facilitated diffusion:
- carrier molecule - high to low concentration
- Sugar (glucose) into red blood cells, no energy used
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Active transport
- Uses energy (ATP)
- uses carrier - low to high concentration
- Coupled transport - secondary
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Na-K-pump
sodium is pumped out and potassium pumped in
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bulk movement:
- Edocytosis: envelopes food and particles in liquids
- a) phagocytosis - to eat
- b) pinocytosis - to drink
- c) receptor-mediated endocytosis
- -molecules in and bind to receptors in plasma membrane
- Exocytosis: discharge of material from cell
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