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
Answer:
<em>The correct option is C) Plants</em>
Explanation:
Option A is false because the cell cannot be an animal cell. This is because an animal cell does not possess a cell wall.
Option B is false because the cell cannot be a bacterial cell. This is because a bacterial cell does not have a nucleus. Their genetic material is dispersed inside the cytoplasm.
Option C is correct because all the organelles, a cytoskeleton, mitochondrion, nucleus, cell wall, and ribosomes, are present inside the plant cells.
Answer:
D) Three of the reaction steps in gluconeogenesis would have prohibitively large, positive free energies if they used glycolytic enzymes for their catalysis.
Explanation:
The glycolytic enzymes catalyze the conversion of glucose to pyruvate, while gluconeogenesis enzymes catalyze the formation of carbohydrates from pyruvate.
Answer:
grasses and shrubs to guanacos to pumas
Desert plants will have very long roots to reach water. Aquatic plants may be able to float to collect water or have sturdy roots to hold them in place.
