Chapter 7 Cell Membrane Flashcards
GLUT
Glucose Transport Protein
Sodium Potassium Pump
Protein moves sodium outside cell & potassium inside
Constantly requires ATP –>
1 ATP to move
3 Sodium Ions (smaller)
and
2 Potassium Ions (larger)
All nerves and lots of cells inside our bodies use these pumps to maintain the balance of Sodium on the outside and Potassium on the inside
Hypertonic
High concentration inside cell –> low concentration outside
Isotonic
State of Equilibrium
Hypotonic
High concentration outside cell–> low concentration inside
Dynamic Equilibrium
Same concentration with mols flowing into & out of the membrane at the same rate
Two types of larger scale active transport
Endocytosis and Exocytosis
Endocytosis
Moving cells inside
Occurs in phagocytes
–> cell membrane folds inwards and creates a phagosome
Concentration Gradient
Moving down the concentration gradient requires no energy –> molecules naturally move from high concentration to low
moving up the concentration gradient does require energy –> low concentration to high
Diffusion
When molecules can dissolve through the lipid bilayer following their concentration gradient
Passive transport
Facilitated Diffusion
Molecules are assisted by transport proteins but still move alongside their concentration gradient to pass through a cell membrane
Passive Transport
Osmosis
Diffusion of water across a membrane
Sodium and Glucose Cotransporter Protein
Both Sodium and Glucose Molecules move into the cell simultaneously through contransporter protein
Sodium moves down it’s concentration gradient (caused by the sodium potassium pump) and glucose moves against its concentration gradient
Another form of ACTIVE transport
Aquaporins
also called water channels, are channel proteins used mainly to facilitate transport of water between cells.
Membrane components made from something attached to a sugar that help with cell recognition
Glycoproteins + Glycolipids
Amphipathic
hydrophilic head
hydrophobic tail
like a frog
Cholesterol does what in cold temperatures?
maintains fluidity by preventing tight packing
Cholesterol does what at high temperatures
prevents movement of phospholipids
2 types of membrane proteins (location-wise)
Peripheral proteins Integral Proteins (incl. trans membrane proteins)
Functions of the Proteins
transport enzymatic activity signal transduction cell-to-cell recognition inter cellular joining attachment to Cytoskeleton and ECM
What kind of transport proteins allow for passage of molecules and ions?
Channel proteins
What kind of proteins bind to molecules, change shape and take them across?
Carrier Protein
Will a Glucose transporter also transport Fructose? (also C6H12O6)
no
What happens to the cell membrane in a plasmolyzed plant cells
It will pull away from the cell wall and the H2O previously inside the cell will fill the space. This can be lethal to the cell
