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Notes on video lecture:
Muscle Contraction and Energetics
Choose from these words to fill the blanks below:
signalling, lactic, intensity, energy, myosin, 15, beta, phosphate, junction, aerobic, carbohydrates, fat, glucose, contraction, eukaryotic, hydrolysis, contractions
skeletal muscle
actin and              filaments interact to generate force
participates in many important cellular processes including muscle                       , cell division cell                     , and the establishment and maintenance of cell junctions and cell shape
ATP-dependent motor proteins best known for their role in muscle contraction and their involvement in a wide range of other                      motility (movement) processes
eukaryote [yoo-KAIR-ee-oht]
an organism whose cells contain a nucleus and other structures enclosed within membranes
muscle contraction
transmission of the electrical impulse across the neuromuscular                  is mediated by the transmitter acetycholine [ah-see-ta-KOHL-een]
the excitation of the motor nerve is transferred to excitation of the muscle membrane as well as the extension of the muscle membrane into the muscle, the T-tubule.
calcium releases into the sarcoplasm (sarcoplasm is comparable to the cytoplasm of other cells, but it houses unusually large amounts of oxygen binding proteins). The calcium concentration in sarcoplasma is also a special element of the muscular fiber by means of which the                          take place
calcium binds with Troponin C which allows the interaction of actin and myosin which produces force
Troponin C is part of the Troponin complex, three regulatory proteins (troponin C, troponin I and troponin T) which are integral to muscle contraction in skeletal and cardiac muscle, but not smooth muscle
ATP (adenonsine triphosphate)
high              molecule
utilized at various steps and very important in muscle contraction
involves                      (cleavage of chemical bonds by the addition of water)
many processes within muscle contraction dependent on ATP
during relaxation, calcium is pumped back into the cytoplasmic reticulum
cytoplasm: the gel-like substance enclosed within the cell membrane
reticulum: compartment
ATPase [ATP-ace]
an enzyme that catalyzes the decomposition of ATP
ATP during exercise
exercise                    is usually measured in maximal oxygen uptake, or VO2 max
VO2 max
V = volume
O = oxygen
max = maximum
the maximum capacity of an individual's body to transport and use oxygen during incremental exercise, which reflects the physical fitness of the individual
up to 100% of VO2 max is largely aerobic
over 100% VO2 max, then non-               energy systems are contributing to the power generation
75% of VO2 max = moderate to intense exercise
if you relied solely on the ATP within your muscle, you would only be able to exercise at this rate for about      seconds
if you increase it to 140% VO2 max, you would last for about 6 seconds
therefore, other metabolic pathways are activated to generate ATP to generate muscle contraction
substrate level phosphorylation
ATP is regenerated by the interactions and exchange of phosphate
anaerobic glycolysis: transformation of                to pyruvate when limited amounts of oxygen (O2) are available
Pyruvic acid: supplies energy to living cells through the citric acid cycle when oxygen is present, and alternatively ferments to produce              acid when oxygen is lacking
oxidative phosphorylation
the metabolic pathway in which the mitochondria in cells use their structure, enzymes, and energy released by the oxidation of nutrients to reform ATP.
carbohydrate and fat drives the re-synthesis of ATP
overview of skeletal muscle energy metabolism
utilization of ATP
creatine phosphate serves as a buffer during levels of intense exercise
creatine phosphate
facilitates transport of high energy                    from mitochondria
                           are degraded through glycolisis and converted to lactate or into the mitochondria which generates ATP
       is another important fuel during exercise
fatty acyl CoAs [koh-ayz] transfer into the mitochondria
the process by which fatty acid molecules are broken down in the mitochondria to generate acetyl-coA, which enters the citric acid cycle, and NADH and FADH2, which are used by the electron transport chain
Muscle Contraction and Energetics