How many ATP will be produced by one glucose in the sarcomere?

(b) Each glucose molecule produces two ATP and two molecules of pyruvic acid, which can be used in aerobic respiration or converted to lactic acid. If oxygen is not available, pyruvic acid is converted to lactic acid, which may contribute to muscle fatigue.

How is ATP used in sarcomere contraction?

ATP prepares myosin for binding with actin by moving it to a higher- energy state and a “cocked” position. Once the myosin forms a cross-bridge with actin, the Pi disassociates and the myosin undergoes the power stroke, reaching a lower energy state when the sarcomere shortens.

Does a sarcomere use ATP?

Within the sarcomere, myosin slides along actin to contract the muscle fiber in a process that requires ATP. Scientists have also identified many of the molecules involved in regulating muscle contractions and motor behaviors, including calcium, troponin, and tropomyosin.

How is ATP used in muscle contraction and relaxation?

ATP binding to myosin during the contractile cycle results in myosin detachment from actin, and energy liberated from subsequent ATP hydrolysis is then used to drive the next contractile cycle. ATP is also used to lower myoplasmic calcium levels during muscle relaxation.

Which of the following processes produces 36 ATP?

Anaerobic cell respiration (glycolysis + fermentation) produces 2 ATP/glucose consumed. Aerobic cell respiration (glycolysis + the Krebs cycle + respiratory electron transport) produces 36 ATP/glucose consumed.

Does the sarcomere shorten during contraction?

For a muscle cell to contract, the sarcomere must shorten. However, thick and thin filaments—the components of sarcomeres—do not shorten. The H zone—the central region of the A zone—contains only thick filaments and is shortened during contraction. The I band contains only thin filaments and also shortens.

Where is ATP used in muscle contraction?

ATP is responsible for cocking (pulling back) the myosin head, ready for another cycle. When it binds to the myosin head, it causes the cross bridge between actin and myosin to detach. ATP then provides the energy to pull the myosin back, by hydrolysing to ADP + Pi.

How many ATP are used in cross bridge cycle?

one ATP molecule
Under most conditions, each force-generating interaction between a myosin cross-bridge and an adjacent actin filament is associated with the hydrolysis of one ATP molecule.

How is ATP made for muscle contraction?

Phosphocreatine. Phosphocreatine, also known as creatine phosphate, can rapidly donate a phosphate group to ADP to form ATP and creatine under anaerobic conditions. Enough phosphocreatine is present in the muscle to provide ATP for up to 15 seconds of contraction.

What changes occur in the sarcomere during muscle contraction?

When (a) a sarcomere (b) contracts, the Z lines move closer together and the I band gets smaller. The A band stays the same width and, at full contraction, the thin filaments overlap. When a sarcomere shortens, some regions shorten whereas others stay the same length.

What are the steps of the contraction cycle?

the 4 steps of the contraction cycle:

• ATP Hydrolysis.
• Cross bridge attachment.
• Power stroke.
• Cross bridge detachment. Step 1: ATP Hydrolysis.

What happens to actin and myosin during sarcomere contraction?

Recall that during sarcomere contraction, the myosin filaments attach to actin filaments and slide along the actin filaments. By this mechanism, the region of overlap between the fibers is increased and the total sarcomere length shortens. Neither actin, nor myosin actually change length; they simply move in relation to one another.

What is the functional sarcomere model of muscle contraction?

The functional sarcomere model describes briefly the sliding filament theory of skeletal muscle contraction in an understandable manner. Configuration with including complete sarcomere, and function of thin filaments (having three proteins; actin, troponin, and tropomyosin) and thick filaments. The M-line and Z-line are identifiable.

What is the I band of a sarcomere?

Inside a sarcomere there are several regions. One such region is the I band, which consists of the actin filaments in the region where they are not superimposed by the myosin filaments. This means that the I band consists only of actin filaments; however, actin filaments aren’t exclusive to the I band.

Do smooth muscle cells have sarcomeres?

Sarcomeres are functional units of muscles, but they are only found in skeletal and cardiac muscle cells; smooth muscle cells do not contain sarcomeres. Actin and myosin filaments still cause the contraction seen in smooth muscle, but are not organized into alignment.