Slide #5

• Actin and myosin assemble into sarcomeres.
• The length of a single sarcomere is measured from one Z-disc to the next.
• The A-band is the length of the myosin fibers.
• It appears dArk in a micrograph of muscle (see below)
• The I-band is the distance from the end of one myosin filament to the beginning of the next.
• It appears lIght in a micrograph.

• The H-zone is the area where actin and myosin aren't in contact with one another.
• The H-zone is bisected by the M-line.