Membrane structure + function II Flashcards
What is major function of plasma membrane?
Barrier, transport, signal transduction
What is major function of inner mitochondrial membrane?
Energy transduction
What is major function of outer mitochondrial membrane?
Barrier
What is major function of RER?
Translation protein processing
What is major function of SER?
Synthesis of complex lipids
What is major function of Golgi?
Post-translational modification + processing for secretion
What is major function of nuclear membrane?
Attachment of chromatin
What is major function of lysosomes?
Hydrolytic enzymes
What is major function of peroxisomes?
Fatty acid oxidation
What are two groups of passive membrane transport?
Non mediated
Carrier mediated
What is non-mediated transport?
Passive diffusion
Diffusion through pore
Driven by conc gradient
What is carrier mediated transport?
Aided by carrier
Uniporter=carry one molecule
What is active membrane transport?
Carrier mediated
Transport molecules against conc gradient
What are 2 transporters called?
Antiporter
Symporter
What is definition of Kt?
Measure of affinity of transporter for its substrate
Lower Kt, the ……. the affinity of transporter for its substrate
Greater
Describe the structure of glucose transporter ?
12 transmembrane domains
Large molecule
What is glucose transport an example of?
Carrier mediated facilitated diffusion process
Describe the kinetics of glucose transport?
Similar to enzyme kinetics
Specific for molecules they transport i.e. D glucose not L glucose
Exhibit saturation type kinetics
What does active transport require?
Requires integral membrane proteins
Selective
What is meant by antiport system?
Transports one molecule in one direction and one molecule in other direction
What is foxglove?
Foxglove is a plant which has chemicals within leaves that has been used therapeutically for long time
What is congested heart disease?
Is heart condition that prevents heart from beating properly
How does foxglove help with congested heart disease?
Foxglove contains an active ingredient called digitalis which is cardiotonic steroid which inhibits Na+/K+ pump
Inhibition of this pump means that intracellular sodium conc increases and it will stimulate 2nd transporter called sodium calcium exchanger
This 2nd transporter pumps sodium out and calcium in
What are 2 glucose transporters found in gut?
SGULT 1 and 2
What is cellular asymmetry?
Cells have some polarity
Different glucose transporter have been differential expressed => expressed in different parts of cells
In order to maintain cellular asymmetry, there are junctions that prevent movement of membrane associated proteins
What is rehydration therapy?
Replaces water lost
Treats symptoms of diarrhoea
Targets co transport of glucose + sodium
What disease is associated with chloride channel?
Cystic fibrosis
What is compartmentalisation?
Separates reactions
Enables local environment to be regulated for instance pH
Bring together components of enzyme activity
Bring reactants together
Separates pathways
What is disease of misdirection?
I cell disease
What is I cell disease?
Lack ability to add mannose 6 phosphate
Product taken by lysosome accumulates so cells therefore will fail to function.
