Unit 2: Cells & Cellular Transport Flashcards
What are the components of a Phospholipid and their attributes?
Phosphate head, polar and hydrophilic
Fatty Acid tails, no polar and hydrophobic
What do Phospholipids make up in the cell?
Plasma cell membrane (bilayer)
What does the cell membrane do? (2)
- separates living cell from aqueous envrionment
- controlls traffic in & out of the cell (some substances can cross over more easily than others)
How are cell membranes semi-permeable?
Only small, no polar molecules are able to pass without assistance (ex. water) and some molecules have protein channels to allow specific material to pass
What are the 6 structures embedded in the membrane?
carbohydrate, peripheral protein, integral protein, glycoprotein, cholesterol, glycolipid
Role of Cholesterol
- effects flexibility of the membrane
- & of unsaturated fatty acids is what determines the fluidity (more=more fluid)
Role of Carbohydrates
- cell-cell recognition
- identification
Why are proteins the best to make channels through the membrane?
Can have multiple properties that allows them to pass through the no polar, polar, hydrophilic, and hydrophobic regions of the phospholipids
How do amino acids connect to the membrane?
- within membrane: nonpolar, hydrophobic amino acids that anchors into the membrane
- outside of membrane: polar, hydrophilic amino acids extend into the extracellular fluid and into the cytosol
What is the name for the water channel?
aquaporin
What are the 6 functions of membrane proteins?
transporter, enzyme activity, cell surface receptor, identification marker, cell adhesion, cytoskeleton attachment
Role of Peripheral Proteins?
identification markers bound loosely on the membrane
Role of Integral Proteins?
penetrates the lipid bilayer as transmembrane proteins that transport proteins as channels or pumps
What is Diffusion?
- universe tends toward disorder (entropy)
- movement of particles from high to low concentration
What is Simple Diffusion?
- Movement from High to Low Concentration
- passive transport that doesn’t require energy
What is Facilitated Diffusion?
- Diffusion through protein channels, specific molecules need the assistance of a channel to pass)
- high to low concentration
What is Active Transport?
- protein pump
- requires energy/ATP
- can allow cells to move against the concentration gradient
What are the 2 methods to moving large molecules?
Endocytosis and Exocytosis
What is Phagocytosis?
the molecules are surrounded by membrane that creates a substance vacuole, which then fuses with a lysosome which contains digestive enzymes
- solid substances
What is Pinocytosis?
the molecules are surrounded by membrane that creates a substance vacuole, which then fuses with a lysosome which contains digestive enzymes
- liquid substances
What is Receptor-Mediated Endocytosis
similar to Phagocytosis, but is triggered by receptor proteins on the cell surface which capture a specific molecule
What is Osmosis?
Diffusion of water
Hypertonic
more solute, less water
Hypotonic
less solute, more water
Isotonic
equal solute, equal water
What are the names for animal cells for the 3 different osmolarities?
Hypo: lysed
Iso: normal
Hyper: shriveled