Where is ATP's energy used during crossbridge cycling? A. When ATP attaches to myosin and causes myosin to pull on actin ("pull" step) B. When ATP attaches to myosin and causes myosin to attach to actin ("grab" step) C. When ATP splits and pushes myosin back into the "cocked" position ("reset" step) D. When ATP attaches to actin and causes actin and myosin to separate ("release" step)

Where is ATP's energy used during crossbridge cycling? A. When ATP attaches to myosin and causes myosin to pull on actin ("pull" step) B. When ATP attaches to myosin and causes myosin to attach to actin ("grab" step) C. When ATP splits and pushes myosin back into the "cocked" position ("reset" step) D. When ATP attaches to actin and causes actin and myosin to separate ("release" step)

BIOLOGY:CONCEPTS+APPL.(LOOSELEAF)

10th Edition

ISBN:9781305967359

Author:STARR

Publisher:STARR

Chapter32: Structural Support And Movement

Section: Chapter Questions

Problem 8SA

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Similar questions

Which is a false statement about skeletal muscle structure?a. A myofibril is composed of multiple muscle fibers.b. Most skeletal muscles attach to bones by connective-tissue tendons.c. Each end of a thick filament is surrounded by six thin filaments.d. A cross-bridge is a portion of the myosin molecule.e. Thin filaments contain actin, tropomyosin, and troponin.
Myosin binds to actin, then bends. What is ATP needed for next? A. to pump the Ca++ “keys” back into the sarcoplasmic reticulum B. to replace the strap and cover the binding sites C. to give feedback to the neuron that contraction occurred D. to un-bind myosin from actin and re-set for another powerstroke.
During which phase of the crossbridge cycle is ATP split into ADP and Pi? A. Immediately preceding the detachment of the myosin head B. Immediately preceding the resetting of the myosin head C. Immediately preceding the power stroke
Outline the role of calcium ions on muscle contraction during a biceps curl. In your answer: A) Describe the role of the nervous system in stimulating the release of calcium ions. b) Outline the role calcium ions play in the 'sliding filament theory?'
What happens when myosin filaments hydrolyze ATP molecules in muscles? a. Actin–myosin complexes dissociate, leading to muscle contraction. b. Actin–myosin complexes dissociate, leading to muscle relaxation. c. Actin–myosin complexes are formed, leading to muscle contraction. d. Actin–myosin complexes are formed, leading to muscle relaxation.
What does ATP binding to myosin head triggers? a. Its association with microtubules b. Its dissociation from actin microfilament c. Conformational change and rotation of myosin head d. Its association with actin microfilament
In muscle cells, magnesium ions compete with calcium ions for binding sites on troponin molecules. If a person has too high a concentration of magnesium ions in the blood, magnesium ions can prevent calcium ions from binding troponin. A) What effect would this have on muscle contraction (strengthen, weaken, or no effect)? B) Use your knowledge of how muscle fibers contract to explain your answer in part A.
How is electrical excitation of a skeletal muscle fiber coupled to muscle contraction? Speculate onwhy the exact mechanism of this coupling has been difficult to determine.
On the molecular level, why does lifting weights consume energy? A. To contract a muscle, acetylcholine binds and pulls calcium ions. ATP binding and hydrolysis are required in the cycle of acetylcholine and calcium-binding and unbinding. B. To contract a muscle, myosin and actin filaments shorten, requiring ATP binding and hydrolysis. O C. To contract a muscle, myosin binds and pulls actin, ATP binding and hydrolysis are required in the cycle of myosin and actin-binding and unbinding. D. To contract a muscle, acetylcholine and calcium filaments shorten, requiring ATP binding and hydrolysis.
Which statement about this diagram is NOT correct? A. Each pink sphere is an actin protein molecule B. The red balls are troponin C. The green things are myosin D. The blue line is tropmyosin E. Ca++ ions attach to the myosin heads to initiate the powerstroke
Predict what would happen to skeletal muscles of the body if an individual exposed to chemicals that inhibited the ATPase activity of myosin
How does calcium release in the muscle fiber result in the cross-bridge for contraction? Use key terms below and identify them on a diagram. Ca+2, troponin, tropomyosin, thin filaments (actin), thick filaments (myosin w/head), cross bridge