All categories

3 years ago

What specific event triggers the uncovering of the myosin binding site on actin?

1 answer:

3 0

Striated muscles contain repeating sarcomeres of overlapping arrays of long, thin actin and thicker myosin filaments. Myosin filaments contains the myosin heads, which are enzymes that can bind to actin, split and make use of the energy from ATP. When muscle contraction starts, myosin heads bind to actin, change their configuration on actin, liberating the products of ATP hydrolysis and causing slide of the actin and myosin filaments. The action of the proteins troponin and tropomyosin on the actin filaments regulates vertebrae striated muscle contraction. The release of calcium ions from the sarcoplasmic reticulum is triggered by the nervous stimulation which causes depolarization of muscle membrane. Calcium ions bind to troponin and thus cause or allow the tropomyosin strands on the actin filament to move so that the part of the actin surface where myosin heads need to bind is uncovered. Contraction then occurs and only stops when the sarcoplasmic reticulum pumps calcium out of the muscle interior.

So basically, what triggers the uncovering of the myosin binding site on actin is the calcium ions binding to troponin and changing configuration.

You might be interested in

Aneli [31]

Answer:

Theeeee answerrrrrrr isssss

tissues

4 0

2 years ago

Plant embryos __________. a. rely on protection and resources supplied from the maternal plant. b. result from fertilization ext

Roman55 [17]

Answer:

A) rely on protection and resources supplied from the maternal plant.

Explanation:

The embryo is a structure formed after the fusion of the male gamete and female gamete. A diploid zygote is formed after cellular division forms the embryo in the female gametophyte and therefore is considered the diploid tissue.

The embryo requires the nutrients for growth and absorb them from the surrounding female gametophyte structure like endosperm in the angiosperm. The embryos grow and form the sporophytic structure.

Thus, Option-A is correct.

5 0

3 years ago

The driving force behind gas exchange in the body is

svlad2 [7]

Answer:

Explanation:

Gas exchange. Gas exchange occurs as a result of respiration, when carbon dioxide is excreted and oxygen taken up, and photosynthesis, when oxygen is excreted and carbon dioxide is taken up. The rate of gas exchange is affected by: the area available for diffusion.

3 0

3 years ago

Who is the biggest ecosystem in the world?

gavmur [86]

Oceans: The Largest Ecosystem on Earth.

3 0

3 years ago

Read 2 more answers

You learn that a Mars lander has retrieved a bacterial sample from the polar ice caps. You obtain a sample of these bacteria and

Misha Larkins [42]

Answer:

a. conservative replication

b. semi conservative replication

c. dispersive replication

d. discontinuous replication

e. continuous replication

The CORRECT ANSWER IS C.

c. dispersive replication

Explanation:

The attached image shows a single band that becomes lighter (in volume) and increase in darker intensity (in times of color) is revealed with consecutive replications. The major pattern that would produce these outcome is dispersive replication.

Conservative replication do reveal two bands (a 14N for the wholly latest molecule, and a 15N for the totally antiquated molecule) after the initial replication. Therefore, this wholly wrong.

Semi-conservative replication reveal an individual band of transitional weight after the initial replication, followed by two bands following the second replication (one of transitional weight, and the other at the 14N position). These two bands is observed in each following replication, with the transitional weight becoming lighter in color as the 14N band is seen to appear darker in color.

The real pattern gives an individual band that pinpoints to all molecules in an individual replicative cycle possessing the same constituents.

Dispersive replication, has its molecules to be a blend of old (15N) and new (14N) strands. Each replication raises the ratio of new to old strands as it explains the reason an individual band is shown raised (lighter in weight) with every replication.

4 0

3 years ago