Answer:
The prolonged electrical depolarization of cardiac muscle cells -that occurs during contraction- is due primarily to the persistent influx of calcium ion
Explanation:
The action potential of the heart muscle is longer with respect to skeletal muscle (around 300 milliseconds), and this is due to the activity of calcium (Ca⁺⁺ ) in the intracellular compartment.
The initial depolarization of cardiac muscle fiber depends on the entry of sodium (Na⁺) into the cell. However, for the action potential to occur and be maintained, Ca⁺⁺ must increase its cytoplasmic levels, which depends on:
- The increase in intracellular sodium induces the release of Ca⁺⁺ from the sarcoplasmic reticulum.
- Calcium entry from the extracellular space through the voltage dependent Ca⁺⁺ channels.
- The entry of extracellular Ca⁺⁺ causes the release of more Ca⁺⁺ ions by the sarcoplasmic reticulum, further increasing its intracellular concentration.
This is how the ion that guarantees the duration of the action potential of the cardiac muscle cell is the Ca⁺⁺.
Learn more:
Calcium, sodium and cardiac muscle cells brainly.com/question/4473795
Enzymes are a type of protein that aid in which of the following processes?
- cellular signaling and regulation
- transport across the cell membrane
- the breakdown of food molecules
- all of these
I think you forgot the answer choices. Is this your question?
If so, it is <u>D) all of these. </u>Enzymes aid in all kinds of microbiological processes, including cellular signalization, regulation and transportation - in addition to the breakdown of nutrients.
Your answer would be the third option
I think that's asexual reproduction.
If the Earths polar Ice melts the ocean levels will increase because of the increased amount of water. Some peninsulas and islands would decrease because they would sink from the risen water.
