B2.1 membrane and membrane transport Flashcards
explain scenario 2, phospholipids in micelle
Miceele contains a hydrophobic core, can carry lipid base susbtances eg.cholesterol
membrane enclosed compartment
explain scenario 3, liposome
liposome is a hydrophilic core, that can carry soluble based susbtances (eg.insulin or fsh) Membrane enclosed compartment
what happens when phospholipids are placed in water
they spontaneaously arrange into a bilayer. The shape can change accordingly to the nature/ property of the fatty acid, tails will always arrange in a way that they are protected from water contact whilst heads touch the water
amphipathic property
whats the phospholopid bilayer also called
fluid mosaic model
whats meant by fluid in fluid mosaic model
constantly in flux, shifting components back and forth to help the cell take in food remove waste let special molecules in and out gather info about the enviornment and communicate with other cells and repais itself. Cholesterol maintain fluidity at right level, can move
whats meant by mosaic in fluid mosaic model
composition of phospholipid molecules in 2 layer sheet it is studded with other types of molecules such as proteins, carbs and cholesterol either floating or embedded
whats meant by model in fluid mosaic model
conceptual framework most accepted
what is the plasma membrane composed of
phospholipid bilayer
cholesterol
proteins: peripheral protein, integral transmembrane protein, glycoproteins
glycolipids
glycolipid
little tree out of phospholipid
acts as a receptor
integral protein
square in between phospholipids not entirely throguh
usually acts as an enzyme, or an adhesive protein
glycoproteins
whole through rectangle with tree in top
tree is a carb
acts as protein receptors
cholesterol
little squares in fatty acid tails
peripheral proteins
rectangle attched to polar head, only bind to plasma membrane at certain times, it temporarily attaches to the plasma membrane
integral transmembrane protein
big rectangle that goes through phospholipid bilayer
can have functions of a protein channel or a protein ion acceptor or a protein pump
integral and integral transmembrane proteins are temporarily or permenantly embrdded in plasma membrane
permenantly
what are the protein fucntions
TRACE
transport; channel or pump
receptor
adhesion
cell recognition
enzyme
explain role of protein as a receptor
these membrane proteins recognize and respond to chemical signals from outside the cell, when the chemical signal binds the membrane protein triggers a response by the cell
explain role of protein for adhesion
proteins that anchor the cell membrane to 1)inner cytoskeleton, 2) proteins outside the cell, 3) other cells
in essence, these membrane bound proteins help cells stick to each other and to their surroudings
explain role of protein for cell recognition
serve as id tags on surface of a cell, often glycoproteins with the carbohydrate portion projecting out of the cell and into extracellular space. These give the cell a biochemical personality and are important in cell to cell recognition
explain role of protein for channel
these membrane proteins allow small molecules to pass through the cell membrane by creating a pore through the membrane
explain role of protein for pump
move small molecules or ions across the cell membrane from low concentration region to high. They use energy from ATP to transport against the concentration gradient
explain role of protein for enzyme protein
promote “catalyze”chemical reactions that synthesize or break apart biological molecules
what type of protein is used for neurotransmission explain
receptor
acetylcholine receptor recognizes and responds to the neurotransmitter acetylcholine
acetylcholine released from vesicles of a neuron and the acetylholine receptors bind the acetylcholine which then triggers a response in the receiving cell
what type of protein is desmosome protein explain
adhesion,they are found in muscle tissues where they bind muscle cells to one another