Cell Structure and Function - Part III

Extracellular Matrix

collection of proteins and carbohydrates that surround the animal cell

Integrin

transmembrane protein that provides a place to attach the cell's outer covering to the cell membrane

Anchor Protein

embedded in the membrane and attaches to the cytoskeleton and extracellular matrix

Fibronectin

glycoprotein that connects the membrane to the cell's outer covering

Proteoglycan

large, protein-rich carbohydrate that has branching and provides a sticky medium that collects water for moisture and adhesion

Collagen

thick, fibrous protein that consists of 4 polypeptides and provides elasticity to the cell's outer covering

Surface Area

represents the amount of exposed membrane on the outside of the cell

Surface Area to Volume Ratio

measurement that decreases as cells grow, so that it lowers the efficiency of cellular exchange when it becomes greater

Membrane Folding

increases the surface area to volume ratio without changing the size of the cell

Cell Size

characteristic that improves the efficiency of exchange with the environment when it decreases

Pump Protein

carrier protein that utilizes energy to transport molecules from a region of lower concentration to one of higher concentration

Active Transport

movement of ions or molecules across a cell membrane into a region of higher concentration, often resulting in the formation of a concentration gradient

ATP Hydrolysis

process of breaking down ATP to release energy

Cotransport

occurs when the passive transport of a solute provides energy for the active transport of other substances

Primary Active Transport

movement of substances that uses the energy of ATP to create a concentration gradient for cotransport

Secondary Active Transport

movement of substances from low to high concentration that first relies of the creation of a concentration gradient to power cotransport

Symport

two molecules travel in the same direction

Antiport

two substances move in opposite directions

Cotransporter

carrier protein that moves more than one kind of molecule at one time

Osmolarity

amount of solutes in a solution

Osmoregulation

regulation of solute concentrations and water balance by a cell or organism

Contractile Vacuole

cell structure that collects extra water from the cytoplasm and then expels it from the cell