bcs2085 unit 5

Smooth muscle is characterized by all the following EXCEPT:

• there are more thick filaments than thin filaments

• it can hold contractions longer than skeletal muscle

• it appears to lack troponin

• there are no sarcomeres

Muscle tissue has all of the following properties EXCEPT:

• contracability

• pushability

• extensibility

• excitability

In muscle contraction, calcium apparently acts to:

• cause ATP binding to actin

• remove the blocking action of tropomyosin

• increase the action potential transmitted along the sarcolemma

• release the inhibition on Z discs

Calcium ions bind to the _____ molecule in skeletal muscle cells.

• troponin

• tropomyosin

• tropomyosin

• myosin

An anaerobic metabolic pathway that results in the production of two net ATP per glucose plus two pyruvic acid molecules is:

•  

  hydrolysis

• the citric acid cycle

• glycolysis

• beta-oxidation

An elaborate network of membranes in skeletal muscle cells that functions in calcium storage is the:

• sarcoplasmic reticulum

• myofibrilar network

• mitochondria

• nucleus

Creatine phosphate functions in the muscle cell by:

• inducing a conformational change in the myofilaments

• forming a temporary chemical compound with myosin

• storing energy that will be transferred to ADP to resynthesize ATP as needed

• forming a chemical compound with actin

During muscle contraction, myosin cross bridges attach to which active sites?

• thick filiments

• z disc

• myosin filaments

• Actin filaments

Which of the following surrounds the individual muscle cell?

• fascicle

• perimysium

• epimysium

• endomysium

The sliding filament model of contraction involves:

•  

  the Z discs sliding over the myofilaments

• actin and myosin shortening but not sliding past each other

• the shortening of thick filaments so that thin filaments slide past

• actin and myosin sliding past each other but not shortening