1. The Dynamic Cell Flashcards
Where are glycolipids found in the cell membrane?
In the external (extra cellular) half of the phospholipid bilayer
What model describes the cell membrane?How was it investigated?
The Fluid Mosaic Model, where proteins are able to move within the bilayer.Investigated using FRAP, proteins move to recover the photobleached area
How is glucose transported in and out of intestinal epithelia?
Active transport (Na+ driven symport) from intestinal lumen -> intestinal epithelia (low to high conc.)Passive transport (Transporter mediated) from epithelia -> ECF (high to low conc.)
How does Botox work?
Blocks meeting of t-snares (on target cell) and v-snares (on transport vesicle) so the vesicle cannot fuse with the target membrane
How are proteins trans located into the mitochondria?
Amino Acid (AA) signal sequence binds to import receptors, inserted into membrane by TOM complex, pushed through the TIM23 complex into the matrix space, signal sequence cleaved by signal peptidase
How are secretatory proteins transported?
Small segment of protein made in cytoplasm, then stopped with an ER signal sequence. The proteins replace the membrane of the ER to continue translation and translocation into the ER. May stay in membrane or pass through and get sent to the Golgi complex and leave for secretion
What causes familial isolated hypoparathyroidism?
Mutations in the signal peptide removed in ER
What are the functions of actin filaments?Microtubules?Intermediate filaments?
- Flexible support around edges of cell, and motor proteins (light band)- Rigid, grow from nucleus- Allow cells to stretch and hold together in tissue
What causes epidermolysis bullosa?
A mutation in the keratin encoding gene (int. filament in epithelial cells). Causes cells to tear
What direction do dyneins and kinesins move in? What do they move along?
Dyneins move towards the -ve end, kinesins move towards the +ve end of microtubules
