Bio (Exam 3) Membrane Structure & Osmosis Flashcards
Membrane Structure & Osmosis Chapter
What is embedded (inside membrane)
hint: 3 answers
- cholesterol
- integral proteins
- phospholipids
What is attached (outside membrane)
hint: 2 answers
- carbohydrates (glycolipid)
- peripheral protein
Fluid Mosaic Model
Mosaic = different things together
Fluid = not solid
a fluid combination of phospolipids, proteins, and other molecules
Plasma membrane functions:
Hint: 3
- Selective barrier
- Seperate cell from outside
- Interface to outside
Membrane fluidity functions
Hint: 2
- Type of phospholipid fatty acid tails
Unsaturated vs Saturated - Amount of cholesterol
Membrane Protein Functions
Hint: 5
- Transport
- Enzymatic activity
- Signal transduction (receive & intermalize signals)
- Cell-cell recognition
- Intercellular joining (cell junctions)
Def of Diffusion
Movement of molecules from [high] region to [low] region
Example: sugar cube in water
Def. of Osmosis
Diffusion of H2O
H2O is a gold-digger that moves towards side of membrane with more solute
Where is H2O a gold-digger?
Osmosis
What are the two factors that regulate membrane fluidity?
Temperature and Cholesterol
What are integral, peripheral and transmembrane proteins?
Integral proteins are ampathatic and transport molecules across the membrane.
Peripheral proteins maintain cell shape and support cell membrane to maintain its structure
Transmembrane maintain cell shape and support cell membrane to maintain its structure.
How are integral and peripheral proteins different from one another?
Integral are permanently embedded within cell membrane and peripheral are attached to the surface at different times.
What is isotonic, hypotonic, and hypertonic
Isotonic is the solute concentration where NO net water moves across the plasma membrane (in & out)
Hypotonic is the solute concentration where cell GAINS water (lysed)
Hypertonic is the solute concentration where cell LOSES water (shrivels)
Why don’t plant cells burst in hypotonic solutions?
Because of the pressure applied by the cell wall. It does not allow the cell to expand to the extent that it will burst.
Osmoregulation
the process that controls solute concentrations and water balance within the cell
