Import Question JSON

Current Question (ID: 13793)

Question:

Which of the following is a true statement about cardiac muscle cells?

Options:

1. They lack an orderly arrangement of actin and myosin filaments
2. They have less extensive sacroplasmic reticulum and thus contract more slowly than smooth muscle cells
3. They are connected by intercalated discs, through which action potentials spread to all cells in the heart
4. They have a resting potential more positive than an action potential threshold

Solution:

Cardiac muscle cells have an orderly arrangement of actin and myosin filaments, like skeletal muscle cells. They also have an extensive sarcoplasmic reticulum and T-tubules, like skeletal muscle cells. However, unlike skeletal muscle cells, cardiac muscle cells are connected by intercalated discs, which contain gap junctions that allow action potentials to spread rapidly from one cell to another. This allows the heart to contract as a single unit, rather than as individual cells. The resting potential of cardiac muscle cells is more negative than the action potential threshold.

Import JSON File

Upload a JSON file containing LaTeX/MathJax formatted question, options, and solution.

Expected JSON Format:

{
  "question": "The mass of carbon present in 0.5 mole of $\\mathrm{K}_4[\\mathrm{Fe(CN)}_6]$ is:",
  "options": [
    {
      "id": 1,
      "text": "1.8 g"
    },
    {
      "id": 2,
      "text": "18 g"
    },
    {
      "id": 3,
      "text": "3.6 g"
    },
    {
      "id": 4,
      "text": "36 g"
    }
  ],
  "solution": "\\begin{align}\n&\\text{Hint: Mole concept}\\\\\n&1 \\text{ mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6] = 6 \\text{ moles of carbon atom}\\\\\n&0.5 \\text{ mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6] = 6 \\times 0.5 \\text{ mol} = 3 \\text{ mol}\\\\\n&1 \\text{ mol of carbon} = 12 \\text{ g}\\\\\n&3 \\text{ mol carbon} = 12 \\times 3 = 36 \\text{ g}\\\\\n&\\text{Hence, 36 g mass of carbon present in 0.5 mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6].\n\\end{align}",
  "correct_answer": 4
}