LESSON 8 Flashcards
a membrane made of two layers of phospholipids with embedded proteins that separates the insides of the cell from its environment
cell membrane
This is a group of organic compounds that are insoluble in water.
lipids
Examples include fats, waxes, oils, and hormones.
lipids
hydrophilic head
phosphate group
hydrophobic tail
fatty acids
having both hydrophilic and hydrophobic parts.
amphipathic molecule
allows certain substances to pass through but not others.
semi- permeable
hese molecules are madeup of building blocks called amino acids joined by peptide bonds.
proteins
_______ penetrate the hydrophobic core
Integral proteins
Integral proteins that span the membrane are called __________
transmembrane proteins
The hydrophobic regions of an integral protein consist of one or more stretches of ____________, often coiled into ___________
nonpolar amino acids; alpha helices
___________ - spans across the membrane
polytropic or transmembrane
_________ attached to only one side of the membrane
monoprotic
are bound to the surface of the membrane
Peripheral proteins
Functions of Proteins
receptor
channel
transmembrane transport
adhesion
cell-cell recognition
enzymatic function
________ are a special class of proteins that function by binding a specific ligand molecule.
Receptors
When a ligand binds to its ______, the ______ can change conformation, transmitting a signal into the cell.
receptor
common ligands are the
neutral molecules water (H2O), ammonia (NH3), and carbon monoxide (CO) and the anions cyanide (CN-), chloride (Cl-), and hydroxide (OH-).