Plasma Membranes Flashcards
What are the five components of a plasma membrane?
Phospholipid bilayer; cholesterol; integral proteins; peripheral proteins; carbohydrates
What is the phospholipid bilayer made of (2 things)
Phosphate hydrophilic head and fatty acid hydrophobic tail
What is cholesterol and where is it found in plasma membrane, and what does it do?
A lipid; Attached between phospholipids; fluidity buffer. Only in animals.
What is phytosterol?
Like cholesterol but in plant plasma membranes.
What do the intergral proteins do in the plasma membrane?
transporters; receptors; enzymes; or binding.
What is a glycoprotein/glycolipid (also known as glycocalyx).
Attracts water to cells surface; aids in cell interactions with its watery environment; important for cell identification and self/non-self determination; used in cell to cell attachments to FORM TISSUES.
What is a glycolipid?
A lipid with a sugar attached.
What do glycocalyx do for plasma membrane?
Attract substances; cell-cell recognition and attachment; form tissues from cells.
What are 3 different types of carrier proteins?
Uniporter; symporter; antiporter
What are carrier proteins?
Move tens of thousands of molecules through the membrane. Specific to ligands.
What does uniporter carrier protein do?
Carries 1 molecule/ion in ONE DIRECTION.
What does symporter carrier protein do?
Carries 2 different molecules/ions in SAME DIRECTION.
What does antiporter carrier protein do?
Carries 2 different molecules/ions in DIFFERENT DIRECTIONS.
What is electrical chemical transport?
When CYTOPLASM is more NEGATIVELY CHARGED than EXTRACELLULAR fluid.
What is exocytosis?
BULK EXPORT by vesicles. For larger molecules. GETTING STUFF OUT.
What is endocytosis?
BULK IMPORT by vesicles and vacuoles. GETTING STUFF IN.
What is primary transport?
Moves an ion or molecule UP it’s electrical gradient using ATP.
What is secondary transport?
An electrical gradient that uses ATP to drive primary transport. Allows ions/molecules to go agains their concentration gradient.
What are channel proteins?
Transport proteins. Move TENS OF MILLIONS molecules/second. Work by being HYDROPHILIC amino acids and ATTRACTING ions and polar molecules. Some are always open. Some are gated.
What is facilitated transport/diffusion?
moves ions and small polar molecules DOWN THEIR CONCENTRATION GRADIENTS through intergral membrane proteins.
What type of proteins participate in faciliated transport?
Channel and carrier proteins.
What are carrier proteins?
Specific to a single substance called a ligand. Binds to ligand, triggers PROTEIN SHAPE TO CHANGE, moves ligand in either direction.
What is a ligand?
A molecule that binds another specific molecule, in some cases delivering a signal in the process.
What is passive transport?
Ions/molecules moving without required energy.
