Karteikarten
The Living Cell
Karten in diesem Stapel (48)
- 1ArchaeaEnzymes form extremophiles e.g. thermostable DNA polymerase
- 2Cell MembraneMaintain chemical integrity by separation - amphipathic bilayer.
Best in liquid crystallised state. Selective permeability - 3Cell wallFully permeable.
Cellulose in plants - most abundant polysaccharide
Peptidoglycan
Chitin - 4Gram BacteriaPOSITIVE -> thick pepdioglycan and membrane under. Purple
NEGATIVE -> membrane, thin peptidoglycan then membrane. Pink. Bacteria won't work - cannot active peptidoglycan - 5Information Storage requirementsMolecule must be stable and accessible - rapid replication without error
- 6DNAMajor and minor grooves allow access to information. Genome = total DNA in organism
- 7GenesNot all encode proteins and some may encode multiple (alternative splicing)
- 8PlasmidsReadily transferred, antibiotic resistance. Horizontal gene transmission - rapid spread
- 9DNA packaging2m in cells. Octomer form nucleosome and further folding.
Chromatin packing regulates gene expression - 10NucleusContains pores, regulated bu NPC above 60,000 Da.
Mammals 3-4000 pores - 11Central DogmaDNA replication -> transcription -> translation
One way system - 12DNA -> proteinTranscription and translation
Spontaneous 3D folding - 13Ribosomes2 main chain rRNA and over 50 proteins. Small and large subunit
70s -> (50s large/ 30s small)
80s -> (60s large/ 40s small)
rRNA made in nucleolus
Smaller subunit = protein assembly framework, large = catalyst for amino acids into polypeptide - 14ERMakes 10% cell volume
Signal peptide recognised by translator proteins to allow them to move through ER - 15ProteomicsLarge scale protein analysis
80,000 proteins in human cell - 16MetabolismChemical reaction release energy from catabolism, or use energy in anabolism
- 17MetabolomicsStudy of cellular metabolites. Changes can occur from stress/ environment.
Use to diagnose/ treat disease/ test drug retention times - 18Specific environmentsEnabled through membranes
Different pH
Proteins organised in arrays - 19PeroxisomeOxidative reactions (e.g. breakdown fatty acids).
Make myelin sheath hence issue could cause neurological disease - 20GlyoxysomeIn plants
Convert fats to sugar via glyoxylate cycle - 21ATPHigh energy final bonds due to phosphate repulsion being overcome
Terminal phosphorylate other molecules to drive anabolic reactions
Chemiosmosis and substrate level phosphorylation - 22ATP synthase100 ATP per second. Rotation action
Chemiomosis - 23MitochondriaOuter membrane smooth and permeable
Inner very impermeable, but rich to proteins for energy transduction
Membrane potential 160mV across inner membrane drives ATP synthesis
0.001% of nuclear DNA - 24ChloroplastPhototransduction
Thylakoid membrane of flattened vesicles forming grand.
3pH difference drives chemiosmosis
Not made denovo - arise by division of different ones - 25Transport of proteinsRequires transit across membranes via transporters
Fate depends on amino acid sequence - no signal remains in cytosol
Others have sorting signals recognised by complementary membrane translators
Sorting signal 15-60 amino acids. Removed by peptidases - 26Entrance/ exit from cellEnter through endocytosis
Leave through exocytosis - 27Vesicle Movementflow along organised routes. Budd off from donor
Polarised Golgi cistern - material enters from cis end and leaves via trans. Small vesicles transfer between cistern - each has different enzyme and environments.
Chemically modified e.g. ogliosaccharide - 28CytoskeletonDynamic. More refined in eukaryotes
3 filament types - microtubules, intermediate filaments, actin filaments - 29MicrotubulesSet position of organelles and direct transport
- 30Intermediate filamentsMechanical strength
- 31Actin filamentsShape and movement of cell
- 32Interactions and assemblyAll interact with accessory proteins to control assembly and structure and regulate interactions e.g. motor proteins
heir structures - non-covalent hence rapid assembly/ disassembly - 33Microtubule25nm, hollow cylinder. Heterodimer of alpha and beta tubular. Bind head to tail into protofilaments and assemble side to side into cylinder of 13 protofilaments.
Polar - alpha minus end, beta positive. New subunits added more readily to + end
Used in plants in cell shape - 34Kinesin and DyeninKinesin to + end and dyeing to - end. Hydrolyse ATP and bind to microtubules and cargo.
Cycle of bind and release moves 1 step at a time
Kinesis 2-3um/sec, dyenin 14um/sec - 35Use motorsAble to move vesicles and mRNA to make more efficient processes
ER binds to kinesin/ Golgi binds to dyenin - 36Actin filaments7nm
2 parallel chains of actin in helix. More rapid growth at + end
High concentration in cell membrane
Used by bacteria to move in cytoplasm - 37MyosinClose relation to kinesin
+ end directed motors, move material along actin
Regulate cell shape - 38Intermediate filaments10-12nm
Elongated subunits
Cross linked in strong arrays for mechanical stability. Keratins stabilise outer layers of skin/hair/nails
Nuclear laming - meshwork outside nuclear envelope - 39Bacteria tublinforms Z ring in bacteria and chloroplasts for cell division
- 40Ciliametachronal waves over long sheets. beat then relax. 6-10u,
dyenin bridges produce sliding - 41Flagellasperm and protists
undulating wave from base to tip. 50-200um
Prokaryote thinner, each attached by hook to protein discs in wall - miniature turbine - 42Ciliary and flagellaRooted in cortex by basal bodies
inconvertible to centriole in centriole
doublets of microtubules in 9+2 configuration, linked by accessory proteins - 43Defects in cilliary dyeninKartagener's syndrome
Lung infections, sperm immotile, opposite body axis - 44Generation of daughter cellsMitosis
(prophase, metaphase, anaphase, telophase, cytokinesis-contractile ring and myosin pinches) - 45Adhesive junctionsMost fundamental in cell communication, Adhesion to each other for common extracellular material secretion.
Transmembrane junction protein links - actin intermediate associated - 46Channel forming junctionsDirect passage between adjacent cells - animal gap junctions for passage of inorganic ions and small polar molecules.
Formed my hexametric complexes
Coordination of cell activities regulated by small molecules
Permeability regulated by Ca2+ or pH - 47PlasmodesmataPlant cell channel forming junctions
Bridge cell wall with cytoplasmic channels
Form as cell divides - cytokinesis incomplete to form - 48Other junctionsOccluding (tight)
Signal -relaying
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- Beschreibung
- Biology of Cells IA (Michaelmas Lectures) Karteikarten am The Living Cell, erstellt von Alice Hathaway am 06/01/2019.
- Erstellt von
- Alice Hathaway
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