Cell Movement

Vocabulary

actin

protein found in all eukaryotic cells. Its monomeric form is the subunit of actin filaments.

cardiac excitation-contraction coupling

contraction and immediate relaxation of the heart muscle

cell motility

movement of cell structures or the entire cell from one location to another

cilium (plural, cilia)

small, hairlike projection from cells that can be used for motility or to filter air in the respiratory system

cross bridge

structure formed when the myosin head is bound to the actin

dense body

anchor point for the sarcomere as the fibers contract

dynein

motor protein that moves along the microtubule found in a flagellum or cilium

filopodium (plural, filopodia)

thin extension of the lamellipodium that contains actin and serves as an antenna to collect information as the cell moves through its environment

flagellum (plural, flagella)

threadlike tail that allows some cells to move

intercalated disk

structure that connects cardiac muscle cells and supports cardiac muscle contraction

kinase

enzyme that transfers a phosphate group from ATP to another molecule

lamellipodium (plural, lamellipodia)

dense network of actin filaments that face out toward the cell membrane

leading edge

edge of the cell that is at the front of the motion of the moving pseudopods

microtubule

hollow tube made of protein that makes up part of the cytoskeleton

myofibril

bundle of thick and thin filaments that make up muscle fibers

myosin

type of motor protein that uses ATP to drive movements along actin filaments

power stroke

movement of cilia toward one side

pseudopod

cytoplasmic extension that is used for location in certain cells and is called a "false foot"

recovery stroke

return of cilia to their original position

sarcomere

repeating units made of actin and myosin that are found in muscle fibers

sliding filament model

motion of actin and myosin filaments sliding past one another during a muscle contraction