呼吸作用與呼吸商：練習題

During the contraction of skeletal muscle, which ion binds to troponin to cause a conformational change in tropomyosin, exposing the myosin-binding sites on actin?

During an experiment investigating the respiration of germinating seeds, it was found that the volume of \(CO_2\) produced was \(14.0\text{ cm}^3\) and the volume of \(O_2\) consumed was \(17.5\text{ cm}^3\). Calculate the respiratory quotient (RQ).

In the mammalian kidney, the loop of Henle acts as a countercurrent multiplier. Which of the following correctly describes the function of the ascending limb?

Which of the following terms describes a pair of muscles that work together to produce movement at a joint, where one muscle contracts while the other relaxes?

According to the sliding filament theory of muscle contraction, which of the following events is triggered by the binding of a new ATP molecule to the myosin head?

What is the primary role of the sinoatrial node (SAN) in coordinating the mammalian heartbeat?

Explain the importance of the brief delay caused by the atrioventricular node (AVN) during the cardiac cycle.

Describe the mechanism by which Antidiuretic Hormone (ADH) increases the reabsorption of water in the collecting duct of the kidney.

Skeletal muscles are composed of different types of muscle fibres adapted for specific types of activity.

(a) Compare fast-twitch and slow-twitch muscle fibres in terms of their myoglobin content and mitochondrial density.

(b) Which fibre type would be more prevalent in the leg muscles of a marathon runner?

The kidney plays a vital role in excretion and osmoregulation.

(a) Explain how the Loop of Henle acts as a countercurrent multiplier to allow the production of concentrated urine.

(b) Describe the effect of antidiuretic hormone (ADH) on the collecting duct when the blood plasma concentration is high.