Using Mice,a Biologist Studying the Cycle of Protein Interactions in Muscle

question 67

Multiple Choice

Using mice,a biologist studying the cycle of protein interactions in muscle contraction has induced a mutation in one of the genes encoding proteins involved in this cycle.She finds that the muscle fibers expressing this mutation are not able to contract.Upon further investigation,she finds that calcium release into the sarcoplasm is normal,and calcium binding to protein filaments is normal.Which hypothesis could explain this mutation?

• A) The mutation occurs at the site on actin where myosin binds.
• B) The mutation occurs in a region of tropomyosin that undergoes conformational change to expose the myosin-binding site on actin.
• C) The mutation occurs in the myosin tail region,preventing titin binding to myosin.
• D) The mutation occurs in myosin and prevents release of inorganic phosphate from the ATP binding site.
• E) All of the above

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Definitions:

Self-Fulfilling Prophecy

A prediction that ensures, by the behavior it generates, that it will come true.

Counterfactual Thinking

The psychological process of imagining alternative outcomes or scenarios that did not actually happen, often starting with "What if..."

Regret

A feeling of sadness, repentance, or disappointment over something that one has done or failed to do.

False Consensus Effect

The cognitive bias to overestimate how much others share one’s beliefs, attitudes, and behaviors.