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What active site exposure during contraction process occurs when calcium binds?
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Is Quiet inspiration an active process?
No, it involves muscle contraction and hence it is active
Describe the major events of muscle fiber contraction?
Muscle fiber contraction is a complex process involving a number of cell parts and chemical substances that result in the sliding movement of the actin and myosin filaments and causes a contraction. A myosin filament is composed of protein strands with globular ends called cross-bridges that extend outward along the length of the filament. The actin filaments have ADP molecules attached to its surface that serve as active sites for linking the cross-bridges of the myosin filaments. Although the process is not completely understood, the sliding filament theory suggests that the myosin cross-bridge attaches to an actin active site and bends slightly, pulling the actin with it. It releases its attachment, straightens, and combines with another active site further down the actin filament, causing the sarcomere to shorten. When the nerve impulse reaches the distal end of its branch, acetylcholine is released into the gap. The acetylcholine diffuses rapidly across the motor end plate and combines with protein receptors in the sarcolemma. This causes a muscle impulse to be generated and pass in all directions over the entire sarcolemma, and through the T-tubules deep into the fiber. The S.R., which contains a high concentration of calcium ions, becomes more permeable and allows the ions to diffuse into the sarcoplasm. When a high enough concentration is present in the sarcoplasm, the linkages between the actin and myosin filaments occur and contraction takes place. The calcium ions are moved quickly back into the S.R. by an active transport system (calcium pump). When enough calcium ions have been removed from the sarcoplasm, the muscle relaxes. At the same time, the acetylcholine is rapidly decomposed by the enzyme cholinesterase. This prevents a single nerve impulse from causing a sustained contraction.
The calcium pump in cell membranes is an example of what?
Active transport
Why is inhilation described as an active process?
OInhalation is a process that relies on contraction of muscles while exhalation is a process that is USUALLY-not always-passive because it relies on the relaxation of muscles. However, when you speak, sing, or blow out a candle the muscles between the ribs and abs contract, making it active.
Exposure to a disease-causing organism results in which type of immunity?
Natural Active Immunity
Is Quiet inspiration an active process?
No, it involves muscle contraction and hence it is active
What is the most important factor in decreasing intracellular concentration of calcium ion after contraction is?
active transport of calcium into the sarcoplasmic reticulum
What is active phase of respiration?
inspirationInpiration involves contraction of muscles. This is an energy requiring process
Which phase of breathing inhalation or exhalation is considered active and passive?
Inhalation is an active process and exhalation is a passive process
Is breathing out in crocodiles active or passive?
Active - as it involves the contraction of muscles.
What is the name of the protein active in muscular contraction?
actin
What is the time in which cross bridges are active called?
contraction
What force is measured by recording instrumentation during contraction?
active
Is a type of immunity that develops from exposure to an antigen. This exposure results in production of antibodies.?
Active Immunity
Which processes use ATP as an energy source in skeletal muscle?
They are needed for contraction and also for relaxation: - For contraction: actin has active sites for binding to myosin, and myosin heads have ATPase activity (ATP hydrolization provokes a conformational change in the myosin head that pushes the actin filament and that is called the "power stroke), and at the end the sarcomere (sorry, google it) shortens. This repeats until calcium levels get lower again (because calcium allows actin to bind myosin, because there are other proteins - troponin, tropomyosin - that block this binding when calcium is not present). This is the cross-bridges cycle. - For relaxation: we have said that calcium ions are necessary for contraction, but we don't want our muscles to contract forever. That's why we need a mechanism to reduce intracellular calcium concentration. That mechanism is a calcium pump (called SERCA) that puts calcium ions again inside the "sarcoplasmic reticulum", which is a kind of storage compartment for calcium in skeletal muscle. This sarcoplasmic reticulum is very developed in skeletal muscle (in contrast with smooth muscle). SERCA pumping is also ATP dependent (active transport). As a curiosity, inside of the sarcoplasmic reticulum, calcium ions (Ca2+) bind to another protein called calcequesterin. They are needed also for processes intrinsic of excitable cells (aka neurons and muscle cells), such as the sodium-potassium pump (active transport)
What is the Active ingredient in antacids?
It is calcium carbonate.
What is locally regulated in the blood by the active form of vitamin D which acts as a cofactor?
Ionic calcium: Calcium absorption is closely related to blood levels of ionic calcium. It is locally regulated by the active form of Vitamn D, which promotes active calcium absorption. pg 900 Anatomy Book
