Chapter 5 Membrane Structure and Function Flashcards
Fluid-Mosaic Model
- Fluidity of the membrane is critical
- Consistency of olive oil at body temperature
- Unsaturated fatty acids make it more fluid
Fluid-Mosaic Model
-Membrane is a fluid phospholipid bilayer in which protein molecules are either partially or wholly embedded.
Imbedded proteins may be __________ or _________.
Peripheral; Integral
The ________ are held in position by interactions of the protein’s hydrophobic and hydrophilic region
proteins
__________ proteins are found on the outer and inner membrane surface.
Peripheral
-Some inner peripheral proteins are held in place by cytoskeletal filaments.
__________ proteins are embedded in the membrane.
Integral
Both phospholipids and proteins may have attached ___________ ______
carbohydrate chains
-Glycolipids and Glycoproteins
Glycolipids and Glycoproteins appear on the ______ surface of the membrane
outer
- used for
- protection
- cell adhesion
- Reception of signal molecules
- cell-cell recognition
Membrane proteins have a variety of functions-
- Channel Proteins
- Carrier Proteins
- Cell Recognition Proteins
- Receptor Proteins
- Enzymatic Proteins
Carrier Proteins
-combine with substance to aid in passage through membrane
Channel Proteins
-provide an opening
Cell Recognition Proteins
-Help body recognize foreign substances.
Receptor Proteins
Allow molecule binding, causing protein to change shape and bring about cellular charge
Passive Transport
- No ATP requirement
* Molecules follow concentration gradient
Active Transport
- Requires carrier protein and ATP
* Can move substances up the concentration gradient
A ___________ is a mixture of a solute dissolved in a solvent
solution
_____________ is usually measure as Weight of solute / volume of solvent or Grams of solute/ liters of solvent
Concentration
Molecules contain ______ energy
heat
-They vibrate and wander randomly
____________ permeable is when only certain molecules can pass through
selectively
________ cannot slip through the membrane or move through the hydrophobic interior
ions
_________ _________ is the force that causes osmosis
osmotic pressure
The _________ of a solution compares the concentration of one solution with the concentration of another solution
tonicity
__________ ___________ - Solute and water concentrations both inside and outside the membrane are equal
Isotonic solution
___________ _________- Cells places in a hypertonic solution will shrink
Hypertonic Solution
___________ ____________-Cells placed in a hypotonic solution will swell
Hypotonic Solution
___________ __________ -No ATP requirement
Passive Transport
__________ _________ -Requires carrier and ATP
Active transport
-small molecules move against their concentration gradient
Large Macromolecules are transported into or out of the cell by __________ __________
vesicle formation
*Proteins,polysaccharides, DNA
Phagocytosis
Cell eating
Pinocytosis
cell drinking
_______ ___________- Specific form of pinocytosis using a coated pit
Receptor Mediated
Animal Cells are surrounded by an __________ ________
Extracellular Matrix
___________ _________-Intercellular filaments between cels
Adhesion Junctions
-hold cells together at cytoplasmic plaques
Tight Junctions
- Impermeable barriers
- cells held tightly together directly by plasma membrane proteins
- Zipper like set of proteins
Gap Junctions
-Plasma membrane channels are joined
*specifically for cell-cell communication
gives some strength
Plant Cell Walls
- Plants have freely permeable cell wall, with cellulose as the main component
- Joined by plasmodesmata
