Flashcards
Cellbiologi - membrane
Flashcards do conjunto (26)
- 1Cell/Plasma membrane functions• Physical and protective barrier
• Regulate transport
• Allow cell-recognition and cell communication
• Mechanical properties
(continuity, capacity for movement and expansion)
• Internal membrane (eukaryotes)
(enclosing an intracellular compartment, differences in protein membranes – responsible for giving each organelle its
distinctive character) - 2Vilken fosfolipid är vanligast?phosphatidylcholine
- 33 main types of membrane lipids- phospolipids
- cholesterol
- glykolipid - 4På vilka sätt kan lipid molekylerna flytta på sig i membranet?Lateral difussion
Flexion
Rotation
Flip-flop - 5Hur påverkar längden på fettkedjan fluiditeten?Längre => mer interaktioner => mindre flytande
- 6Hur reguleras fluiditeten hos djurceller?Av kolesterol
- 7Var syntetiseras nya membran lipider?På cytosol sidan av ER
- 8scramblaseFlyttar fosfolipider mellan de båda lagrena för att få en symmetrisk form
- 9Flippasesflyttar specifika fosfolipider mellan de båda lagrena => assymetriskt cellmembran med olika typer av lipider på båda sidorna
- 10Orientation of membrane proteins is...crucial for their function
- 11Var finns glykolipiderna?Uteslutande i icke-cytosol lagret
- 12Vilka molekyler kan ta sig genom cellmembranet och vilka kan inte det?Kan ta sig igenom:
- små opolära molekyler
- väldigt små polära (oladdade molekyler)
Kan inte ta sig igenom:
- större opolära molekyler
- laddade molekyler - 13Vad har membran proteinerna för funktion?Transportprotein,
receptorer,
enzym,
"anchor" - 14På vilka olika sätt kan proteiner vara "fästa" i membranet?Integral membrane proteins:
Transmembrane,
monolayer associated alfa helix,
lipid-linked
Peripherical membrane proteins:
proten-attached - 15Cell cortexThe cell cortex, also known as the actin cortex or actomyosin cortex, is a specialized layer of cytoplasmic protein on the inner face of the plasma membrane of the cell periphery. It functions as a modulator of plasma membrane behavior and cell surface properties.
Meshwork of fibrous proteins attached to the membrane via
transmembrane proteins - 16Glykocalyxcarbohydrate layer
Sugar coat at the non-cytosolic (extracellular) side
Glycolipids
glycoproteins
proteoglycans
Functions:
Protection cell surface from mechanical and chemical damage/stress
Important in cell-cell recognition and cell-adhesion - 17Types of membrane transport proteins:- Transporters
- Channels
Active transport (pumps)
passive transport - 18Electrochemical gradient= net driving force = sum of the force from the concentration
gradient of a solute and the force from the membrane potential - 19Glucose transporterpassive
- 20Na+/K+ pump3 Na+ ut
2 K+ in
ATP driven - 21Ion selectivity depends on:diameter and shape of the ion channel
distribution of charged amino acids of the channel - 22Gap junctionsLarge channels between 2 cells to provide electrical and metabolic coupling
- 23Different types of ion channels depending on stimuli for opening the gateVoltage gated
ligand- gated (extracellular ligand) (något binder in)
ligand-gated (intracellular ligand)
mechanically gated - 24active signalling mechansim...
- 25Action potentialStimulus
→membrane potential of the plasma
membrane becomes less negative
→opening of additional voltage-gated Na+
channels = depolarization causes Na+
influx
→At ca +40 mV electrochemical driving force
for Na+ is zero = no more influx of Na+
→ return to resting potential by opening of voltage-gated K+ channels = repolarisation = K+ efflux - 26—
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- O usuário eliminou as informações de disciplina FlashCards sobre Cellbiologi - membrane, criado por Usuário eliminado em 19-02-2021.
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- Usuário eliminado · fev 2021
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- Criado por Tova A · 3 fev 2021
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