Chap. 7 (Vocab.) Flashcards
Amphipathic
Having both a hydrophilic and hydrophobic region
Integral Protein
- Proteinfully or partially permanently embedded in cell membrane
- Amphipathic
- Interacts with hydrophobic. phospholipid parts with its hydrophobic interior of amino acids
Transmembrane Protein
Type of integral protein that is fully embedded in cell membrane
Peripheral Protein
Proteins loosely associated with cell surface, not embedded in it
Cell-cell Recognition
- Cell’s ability to distinguish one neighboring cell from another
- Due to carbohydrates
Glycolipid
Lipid with carbohydrate covalently attached to it
Glycoproteins
Protein with carbohydrate covalently attached to it
Selective Permeability
Property that allows membrane to regulate material flow
Transport Protein
Transmembrane protein that helps substances cross the membrane
Channel Proteins
Hydrophilic channel that certain molecules/ions use as a tunnel through the membrane
Aquaporin
Channel proteins that allows water to pass through membrane
Carrier Proteins
Transport protein that binds to molecules and change shape to shuttle them across membrane
Diffusion
Molecules move from a high to low concentration area without the need of assistance of proteins
Dynamic Equilibrium
As many molecules cross the membrane in one direction as in the other
Concentration Gradient
Difference in concentration of a substance between two areas (passive transport)
Passive Transport
DIffusion across membrane where no energy is required
Osmosis
Water molecules pass through semipermeable membrane from more concentrated area to less concentrated area until it is equal on both sides
Tonicity
- Ability of a solution to change the volume of a cell by affecting the cell’s water content
- Depends on concentration of solutes that cannot pass membrane relative to that inside the cells
Isotonic
Solute concentration is the same as that of inside the cell; no net water movement
Hypotonic
Solute concentration is greater than that inside the cell; cell loses water
Hypertonic
Solute concentration is less than that inside the cell; cell gains water
Turgid
Swollen cell due to fluids
Flaccid
Soft cell
Plasmolysis
Plant cell loses water to its surrounding environment, causing the cytoplasm and plasma membrane to shrink away from the cell wall
Facilitated DIffusion
Larger molecules cross membrane w/o energy input using transport proteins
Ion Channels
Proteins that allow electrically charged particles, or ions, to pass through cell membranes
Gated Channels
Ion channel that opens or closes based on response from stimuli
Active Transport
Requires energy, usually in ATP hydrolysis, to move substances against concentration of gradient (carrier proteins)
Sodium-potassium Pump
Transport protein in plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell
Membrane Potential
Voltage across a membrane
Electrochemical Gradient
Diffusion of ions across membrane, due to:
1. Chemical Force
2. Electrical Force
Electrogenic Pump
Transport protein that generates voltage across membrane
Proton Pump
- Electrogenic pump for fungi, plant, and bacteria cells
- Activey transports hydrogen ions out of cell
Cotransport
- Activey transporting two substances across a cell membrane at the same time
- Uses one substances movement to power the other
Exocytosis
Transport vesicles migrate to the membrane, fuse with it, and release their contents outside the cell
Endocytosis
Cell takes in macromolecules by forming vesicles from the plasma membrane
Phagocytosis
- Cell engulfs a particle in a vacuole
- The vacuole fuses with a lysosome to digest the particle
Pinocytosis
Cell ingests extracellular fluid + its dissolved fluids
Receptor-Mediator Endocytosis
Cells selectively absorb specific molecules from their environment trhough receptor proteins
Chemical Force
Ion concentration gradient
Electrical Force
Effect on membrane potential on ion’s movements
