Biological Membranes Flashcards
primary membrane component, both my mass and mole fraction
lipids (triacylglycerols, free fatty acids, glycerophospholipids, cholesterol, waxes)
act as transporters, cell adhesion molecules, and enzymes within the cell membrane
proteins
can form a protective glycoprotein coat around the cell membrane and also function in cell recognition
carbohydrates
cell-cell junctions:
allow for rapid exchange of ions and other small molecules between adjacent cells
gap junctions
cell-cell junctions:
prevent solutes from leaking into the space between cells via a paracellular route, but do not provide intercellular transport like gap junctions
tight junctions
cell-cell junctions:
bind adjacent cells by anchoring to their cytoskeletons; anchor layers of epithelial tissue together
desmosomes and hemidesmosomes
membrane transport:
does not require energy because the molecule is moving down its concentration gradient or from an area with higher concentration to an area with lower concentration
passive transport
passive transport:
does not require a transporter; small, nonpolar molecules passively move from an area of high concentration to an area of low concentration until equilibrium is achieved
simple diffusion
passive transport:
uses transport proteins to move impermeable solutes across the cell membrane
facilitated diffusion
membrane transport:
requires energy in the form or ATP or an existing favorable ion gradient
active transport