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
The answer is 23 chromosomes.
Answer:
A possible hypothesis would be:
IF a yeast cell is supplied with maltose sugar, THEN it would yield the greatest amount of energy when metabolized by bacteria
Explanation:
The hypothesis is a testable explanation aimed at providing a theoretical explanation to a question. The hypothesis is a predictive statement about the possible solution, which can be tested. A hypothesis must be testable via experimentation. It often has an IF, THEN format.
Hence, in the case experiment where a student wanted to know which sugar (maltose, glucose or sucrose) would yield the greatest amount of energy for the cell when metabolized by mitochondria. A possible hypothesis of this experiment will be that: IF a yeast cell is supplied with maltose sugar, THEN it would yield the greatest amount of energy when metabolized by bacteria
Note that, this hypothesis must be testable by conducting an experiment and it doesn't have to be true. It can be disproved or proved by the outcome of the experiment. In this case, the hypothesis is giving an educated guess that maltose is the sugar that will yield the greatest amount of energy for yeast cells
The answer is D.
An endothermic reaction involves absorbing heat whereas an exothermic involves releasing heat.
