Biochemical Pathways in Muscle Function Flashcard

Front

During a sprint race, Jackson's muscles are working hard and not getting enough oxygen. What is the primary process involved in his muscle cells to produce energy in this anaerobic condition?

Back

Glycolysis

Answer explanation

In anaerobic conditions, Jackson's muscle cells primarily rely on glycolysis to produce energy. This process breaks down glucose into pyruvate, generating ATP without the need for oxygen.

Front

Where does glycolysis occur within the cell?

Back

Cytoplasm

Answer explanation

Glycolysis occurs in the cytoplasm of the cell, where glucose is broken down into pyruvate. This process is essential for cellular respiration and energy production.

Front

What is the net gain of ATP molecules per glucose molecule during glycolysis?

Back

2 ATP

Answer explanation

During glycolysis, a net gain of 2 ATP molecules is produced per glucose molecule. Although 4 ATP are generated, 2 ATP are consumed, resulting in a net gain of 2 ATP.

Front

During a marathon, what is the main source of energy for Isla as she maintains a steady, moderate pace?

Back

Oxidative phosphorylation

Answer explanation

During a marathon, Isla primarily relies on oxidative phosphorylation for energy, as it efficiently produces ATP using oxygen, which is crucial for sustaining a steady, moderate pace over a long duration.

Front

Which molecule enters the citric acid cycle during aerobic metabolism?

Back

Acetyl-CoA

Answer explanation

In aerobic metabolism, pyruvate from glycolysis is converted into Acetyl-CoA, which then enters the citric acid cycle. Therefore, Acetyl-CoA is the correct molecule that enters the cycle.

Front

What is the primary cause of muscle fatigue during high-intensity exercise?

Back

Accumulation of metabolic byproducts

Answer explanation

During high-intensity workouts, muscle fatigue primarily results from the accumulation of metabolic byproducts like lactic acid, which interfere with muscle function, rather than from ATP production or oxygen depletion.

Front

Which ion is essential for muscle contraction?

Back

Calcium

Answer explanation

Calcium ions are crucial for muscle contraction as they trigger the interaction between actin and myosin filaments in muscle fibers, enabling contraction. Without calcium, muscles cannot contract effectively.

Front

What happens to lactate in muscles during recovery after muscle fatigue?

Back

It is converted back into pyruvate

Answer explanation

During recovery, lactate in Ava's muscles is converted back into pyruvate. This process helps to restore energy and allows for the continuation of aerobic metabolism, aiding in muscle recovery.

Front

What adaptation occurs in Noah's muscles as a result of his endurance training?

Back

Increase in mitochondrial density

Answer explanation

Endurance training leads to an increase in mitochondrial density in muscles, enhancing their ability to produce energy efficiently. This adaptation supports prolonged physical activity, making it crucial for marathon training.

Front

Which type of muscle fibers are more efficient at using oxygen to produce ATP?

Back

Slow-twitch fibers

Answer explanation

Slow-twitch fibers are more efficient at using oxygen to produce ATP, making them ideal for endurance activities. In contrast, fast-twitch fibers rely more on anaerobic processes and are less efficient in oxygen use.