Question

Unlike skeletal muscle, the muscle cells of the heart (called "cardiomyocytes") metabolize very little glucose, relying almost exclusively on metabolism of fatty acids for their energy. Which of the following statements are likely to be true of cardiomyocytes, but NOT skeletal myocytes? (select two answers)

a. low levels of glycogen storage, even when blood glucose is high
b. high levels of glycogen storage, even when blood glucose is low
c. low lactate production, even at high activity
d. high lactate production, even at low activity
e. many mitochondria compared to other cells
f. few mitochondria compared to other cells

Answer 1

The answer is A and C

Step-by-step explanation:

Since cardiomyocytes are dependent on fatty acids, they rely on oxidative phosphorylation to generate energy, and consume very little glucose. Due to this, they have very low need for fermentation of pyruvate. In fact, they can absorb lactate generated by skeletal myocytes and erythrocytes and oxidize it for additional energy. Another consequence of this metabolism is that cardiomyocytes store little or no glucose as glycogen.

Skeletal myocytes and cardiomyocytes both have high energy needs and thus have more mitochondria than other cells. Cardiomyocytes have an even greater density of mitochondria than skeletal myocytes because they depend almost entirely on oxidative phosphorylation for their energy needs. This dependence on oxidative phosphorylation also explains the extraordinary sensitivity of cardiac muscle to hypoxic (low-oxygen) events. Without oxygen, cardiomyocytes rapidly run out of energy and can quickly die.

Answer 2

Answer: A. low levels of glycogen storage, even when blood glucose is high.

C. low lactate production, even at high activity.

Step-by-step explanation:

Cardiomyocytes are also known as the myocardiocytes. They are the cells which makes up make up the muscle if the heart. They're responsible for the generation of the contractile force in the heart which helps in the pumping if blood.

From the options given, the statements that are likely to be true of cardiomyocytes, but not of skeletal myocytes include:

• low levels of glycogen storage, even when blood glucose is high.

• low lactate production, even at high activity.