BIO 264 STUDY EXAMS GUIDE QUESTIONS AND
ANSWERS SURE A+
✔✔Arrange these structures as they participate in excitation-contraction.
1. Sarcoplasmic Reticulum
2. T-tubules
3. Sarcolemma
4. Calcium Ions - ✔✔Sarcolemma, T tubules, sarcoplasmic reticulum, calcium ions
✔✔A child ingested an organophosphate poison used to kill insects. Soon the child's
muscles began tetanic contractions. Predict what occurred at the synaptic cleft. - ✔✔An
increased accumulation of acetylcholine in the synapse.
✔✔Botulism food poisoning results from a toxin (poison) produced by bacteria. Death
from botulism results from the uncontrolled relaxation of the respiratory muscles
(diaphragm). Assuming that this toxin affects the neuromuscular junction, what could be
a way in which this toxin could cause these muscles to relax and no longer contract. -
✔✔The botulism toxin could block the release of acetylcholine from the pre-synaptic
terminal of a neruomuscular junciton.
✔✔Neurotransmitters are stored in vesicles in _________. - ✔✔Axon Terminal
✔✔The release of ACh has what effect on the Sarcolemma? - ✔✔Increases
permeability of the sarcolemma.
✔✔Myosin myofilaments are attached to what zone in the Sarcomere? - ✔✔the M line.
✔✔Muscle myofibrils contain what Proteins? - ✔✔Contain myosin and actin
myofilaments.
✔✔A contractile thread (Cylindrical shape) that extends the length of the muscle fiber is
called a ________? - ✔✔Myofibril
, ✔✔The striated appearance of skeletal muscle results from the _________. -
✔✔Sarcomere organization (From the arrangement of the Myofilaments)
✔✔Name the 3 phases of muscle twitch - ✔✔Latent Period (Lag Period)
Contraction Period
Relaxation Period
✔✔Which of the following is NOT a source of ATP for muscle contraction?
Creatine phosphate
Glycolysis in an anaerobic environment
Aerobic respiration
Recovery oxygen consumption - ✔✔Recovery oxygen consumption
✔✔During the depolarization phase of an action potential, the permeability of the
plasma membrane to which ion increases? - ✔✔Na+ increases.
✔✔The Ca2+ required for skeletal muscle contraction is released from where? - ✔✔Is
released from the sarcoplasmic reticulum
✔✔What is the structural and functional unit of the skeletal muscle cell? - ✔✔Sarcomere
✔✔If sodium ions cannot enter a muscle fiber in response to a stimulus What happens
to the muscle? - ✔✔Contraction cannot occur
✔✔In order for muscle relaxation to occur what must happen on the actin filament? -
✔✔The active sites on actin must be blocked
✔✔You are hired to work in a laboratory to measure the rate of human muscle
contraction. Which of the following might decrease in quantity in muscle cells
undergoing contractions?
A) ATP
B) carbon dioxide
C) water
D) lactic acid
E) sodium - ✔✔ATP
✔✔Transverse tubules do what? - ✔✔Transmit muscle impulses into the cell interior
✔✔Which of the following is NOT true of the relaxation of a muscle fiber?
ANSWERS SURE A+
✔✔Arrange these structures as they participate in excitation-contraction.
1. Sarcoplasmic Reticulum
2. T-tubules
3. Sarcolemma
4. Calcium Ions - ✔✔Sarcolemma, T tubules, sarcoplasmic reticulum, calcium ions
✔✔A child ingested an organophosphate poison used to kill insects. Soon the child's
muscles began tetanic contractions. Predict what occurred at the synaptic cleft. - ✔✔An
increased accumulation of acetylcholine in the synapse.
✔✔Botulism food poisoning results from a toxin (poison) produced by bacteria. Death
from botulism results from the uncontrolled relaxation of the respiratory muscles
(diaphragm). Assuming that this toxin affects the neuromuscular junction, what could be
a way in which this toxin could cause these muscles to relax and no longer contract. -
✔✔The botulism toxin could block the release of acetylcholine from the pre-synaptic
terminal of a neruomuscular junciton.
✔✔Neurotransmitters are stored in vesicles in _________. - ✔✔Axon Terminal
✔✔The release of ACh has what effect on the Sarcolemma? - ✔✔Increases
permeability of the sarcolemma.
✔✔Myosin myofilaments are attached to what zone in the Sarcomere? - ✔✔the M line.
✔✔Muscle myofibrils contain what Proteins? - ✔✔Contain myosin and actin
myofilaments.
✔✔A contractile thread (Cylindrical shape) that extends the length of the muscle fiber is
called a ________? - ✔✔Myofibril
, ✔✔The striated appearance of skeletal muscle results from the _________. -
✔✔Sarcomere organization (From the arrangement of the Myofilaments)
✔✔Name the 3 phases of muscle twitch - ✔✔Latent Period (Lag Period)
Contraction Period
Relaxation Period
✔✔Which of the following is NOT a source of ATP for muscle contraction?
Creatine phosphate
Glycolysis in an anaerobic environment
Aerobic respiration
Recovery oxygen consumption - ✔✔Recovery oxygen consumption
✔✔During the depolarization phase of an action potential, the permeability of the
plasma membrane to which ion increases? - ✔✔Na+ increases.
✔✔The Ca2+ required for skeletal muscle contraction is released from where? - ✔✔Is
released from the sarcoplasmic reticulum
✔✔What is the structural and functional unit of the skeletal muscle cell? - ✔✔Sarcomere
✔✔If sodium ions cannot enter a muscle fiber in response to a stimulus What happens
to the muscle? - ✔✔Contraction cannot occur
✔✔In order for muscle relaxation to occur what must happen on the actin filament? -
✔✔The active sites on actin must be blocked
✔✔You are hired to work in a laboratory to measure the rate of human muscle
contraction. Which of the following might decrease in quantity in muscle cells
undergoing contractions?
A) ATP
B) carbon dioxide
C) water
D) lactic acid
E) sodium - ✔✔ATP
✔✔Transverse tubules do what? - ✔✔Transmit muscle impulses into the cell interior
✔✔Which of the following is NOT true of the relaxation of a muscle fiber?
