Motor Unit Fibers Overview

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What type of fibers are predominant in the drumstick of a chicken or turkey?

Cardiac fibers

Slow twitch fibers (correct)

Intermediate twitch fibers

Fast twitch fibers

What acts as the regulatory subunit for myosin light chain kinase in muscle cells?

Collagen

Calmodulin (correct)

Troponin

Myoglobin

What type of enzyme is myosin light chain kinase?

Hydrolase enzyme

Phosphatase enzyme

Kinase enzyme (correct)

Ligase enzyme

What is the role of myosin light chain phosphorylation in muscle contraction?

Promotes cross-bridge cycling Signup and view all the answers

What do all kinases have in common in terms of their enzymatic activity?

Add phosphate groups to proteins Signup and view all the answers

Where are the thin filaments attached in muscle cells that lack Z-lines?

Dense bodies Signup and view all the answers

What type of muscle fibers are most fuel-efficient and tend to be weaker?

Slow-oxidative fibers Signup and view all the answers

Which type of muscle fibers are important for power and endurance, suitable for mile track runners?

Fast-oxidative fibers Signup and view all the answers

What is the main function of creatine phosphate in muscle cells?

Energy storage Signup and view all the answers

Which process results in a lower ATP yield but is faster and anaerobic?

Glycolysis Signup and view all the answers

What is the function of myoglobin in muscle cells?

Oxygen binding and transportation Signup and view all the answers

Which type of muscle fibers are the most powerful but the least efficient in fuel utilization?

Fast-glycolytic fibers Signup and view all the answers

What is the term used to describe the rigid cross-linking of thick filaments to thin filaments in muscles?

Rigor associated with death Signup and view all the answers

What initiates the binding step in muscle contraction that is calcium dependent?

ATP presence Signup and view all the answers

What causes the displacement of the Myosin head during muscle contraction?

Spontaneous conformational change Signup and view all the answers

Which process re-energizes the Myosin head during muscle contraction?

Hydrolysis Signup and view all the answers

In muscle cells, what triggers the activation of contraction in response to neuromuscular transmission?

Acetylcholine release Signup and view all the answers

What event causes an excitatory end-plate potential leading to an action potential in the muscle membrane?

Release of acetylcholine Signup and view all the answers