BSC 2085C Study Cards ( Chapter 9 )

Which of the following processes produces 36 ATP?

Krebs cycle and Oxidative Phosphorylation

Why would inflammation of the knee joint be a "good thing" when there's been an acute quadriceps injury?

because fluid accumulation reduces joint movement

Proper application of RICE--rest, ice, compression, and elevation--can effectively control inflammation due to an ankle sprain. Why would compression provided by a correctly wrapped elastic Ace bandage be helpful in preventing further inflammation?

because it immobilizes/stabilizes an injured ankle.

The site where a motor neuron excites a skeletal muscle fiber is called the neuromuscular junction. Place the sequence of events that occur at the neuromuscular junction.

Ca2+ enters the axon terminal. Synaptic vesicles release ACh. ACh binds to ACh receptors. Ligand-gated cation channels open. Na+ enters and K+ exits. Membrane potential is less negative.

The Cross Bridge Cycle starts when _________.

Ca2+ from the sarcoplasmic reticulum binds to troponin.

What is the type of chemical reaction used to rebuild ADP into ATP?

Dehydration Synthesis

Which of the following is/are mechanism(s) to end neural transmission at the neuromuscular junction?

* ACh is broken down into acetic acid and choline by the enzyme acetylcholinesterase (AChE). ACh binds to ACh receptors. * ACh diffuses away from the synaptic cleft. ACh is taken up by the axon terminal via endocytosis.

Which of the following processes produces molecules of ATP and has two pyruvic acid molecules as end products?

Glycolysis

What structure most directly stimulates a skeletal muscle fiber to contract?

Motor neuron

The "rest and recovery" period, where the muscle restores depleted reserves, includes all of the following processes EXCEPT __________.

Oxygen rebinds to myoglobin. Glycogen is synthesized from glucose molecules. * Pyruvic acid is converted back to lactic acid. ATP is used to rephosphorylate creatine into creatine phosphate.

Inadequate calcium in the neuromuscular junction would directly affect which of the following processes?

Release of acetylcholine from the synaptic vesicles

Rank the sequence of events at the NMJ that initiate an action potential in the muscle fiber, from first to last.

Step 1: Action potential arrives at the axon terminal. Step 2: Calcium Ions enter the Axon Terminal. Step 3: Synaptic Vesicles fuse to membrane of Axon Terminal. Step 4: Acetylcholine is released into the Synaptic Cleft. Step 5: Acetylcholine binds to its receptors on the Junctional Folds. Step 6: Junctional Folds become Depolarized. Step 7: Action Potential is initiated on the Sarcolemma.

Match the term in the left column to the blanks near their definition on the right.

Synaptic cleft : the space between the axon terminal and junctional folds. Acetylcholine receptor : a type of chemically-gated ion channel located on the junctional folds of the muscle fiber. Synaptic vesicle : membranous sac located in the axon terminal that contains neurotransmitter. Acetylcholine : neurotransmitter that stimulates skeletal muscle contraction. Acetylcholinesterase : enzyme located in the synaptic cleft that breaks down acetylcholine. Calcium channel : a type of voltage-gated ion channel located on the axon terminal. Sodium channel : a type of voltage-gated ion channel located on the sarcolemma of the muscle fiber.

Which type of muscle fiber has a large quantity of glycogen and mainly uses glycolysis to synthesize ATP?

White Fast Twitch Fibers

Place the events that occur during excitation-contraction coupling in the correct order from left to right.

[ Starting: AP generated by Motor Neuron ] AP propagates along sarcolemma AP travels down T tubules to triads Voltage-sensitive proteins open Ca2+ channels Sarcoplasmic reticulum releases Ca2+ Ca2+ levels in sarcoplasm increase [ Ending: Contraction of Skeletal Muscle Fiber ]

Place the steps that occur during a single Cross Bridge Cycle in the correct order from left to right.

[ Starting: ATP Hydrolosys activates the myosin head. ] The activated myosin head binds to actin, forming a cross bridge. ADP is released and myosin slides the thin filament toward the center of the sarcomere. ATP binds to the myosin head and detaches it from actin. ATP is hydrolyzed to ADP and Pi and the energy released re-cocks the myosin head.

Myasthenia gravis is a disease resulting from an autoimmune attack on the ACh receptors of the motor end plate. Binding of antibodies to the ACh receptors results in generalized muscle weakness that progresses as more ACh receptors are destroyed. Which of the following medications would help alleviate the muscle weakness?

a drug that blocks the release of acetylcholine (botulinum toxin) * a drug that binds to and inactivates acetylcholinesterase (neostigmine) a drug that binds to the acetylcholine receptor and prevents it from opening (curare) a drug that prevents acetylcholine from being loaded into synaptic vesicles (vesamicol)