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Cell Biology - Coggle Diagram
Cell Biology
MEMBRANE TRANSPORT
Passive Transport
High To Low Concentration Gradient
Types of Passive Transport
Simple Diffusion
When nonpolar & small polar substances
directly move through a phospholipid bilayer
molecule diffuses across lipid bilayer e.g. water, steroid hormones. molecules in a solution move toward a region where they are less concentrated
Osmosis Movement of a substance through a semipermeable membrane (e.g. movement of water through membrane)
The diffusion of water from a region of higher water potential to a region of lower water potential down a water potential gradient through a partially permeable membrane. Passage of water molecules down the water potential gradient across a partially permeable membrane. passive transport = no energy req'd
Facilitated Diffusion Requires channel protein to move through membrane
protein-mediated diffusion across membrane (no energy required). diffuse through the plasma membrane by moving through a specific integral protein
No energy required
Function: used to maintain equilibrium in the internal and external cell environment
Movement across the membrane down the concentration gradient
Active Transport
Low To High Concentration Gradient
Types of Active Transport
Pumps
Symports
substances that 'want' to move carries another substance with it against the concentration gradient. (e.g Sodium-Glucose Transport Protein)
Antiport
transport two substances in opposite directions (e.g the Sodium Potassium Pump)
Requires energy to function & for cell membrane to change shape
Endocytosis- process by which cells take in substances from outside of the cell by engulfing them in a vesicle.
Phagocytosis
Cell Eating- Uptake of solid material that's too big for diffusion or active transport.
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Pinocytosis
Cell Drinking- Uptake of liquid too big for diffusion or active transport.
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Receptor mediated endocytosis
A targeted version of endocytosis where receptor proteins in the plasma membrane ensure only specific, targeted substances are brought into the cell.
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Exocytosis
Used to 'export' products from a cell.
The product is packed into 'vesicles' by the endoplasmic reticulum. The Golgi Apparatus fuses the vesicles to the membrane and releases product into the external environment
Movement across membrane against the concentration gradient
Requires ATP energy
Function: to carry ions and molecules through cell membrane
PLASMA MEMBRANE
STRUCTURE
membrane made of a double layer of lipids with which proteins are embedded
FUNCTION
externally facing proteins act as receptors and in cell-to-cell recognition
serves as an external cell barrier
acts in transport of substances into or out of cell