Question

Assertion: Red fibres are referred as aerobic muscles Reason: These muscles contain large number of mitochondria which utilize the large amount of oxygen stored in them for ATP production.

Short answer

The assertion and the reason given are correct. Red fibres are referred to as aerobic muscles because they contain a large number of mitochondria which utilize the large amount of oxygen stored in them for ATP production.

Step-by-step solution

Understanding terms and statements

Firstly, let's understand the provided statements. Red fibres indeed are often referred to as 'aerobic muscles' because they are involved in long duration, endurance activities which require aerobic metabolism. This statement is correct. The reason also seems correct on the surface: red fibres indeed contain numerous mitochondria that are essential for ATP production, which is a process that utilizes oxygen.

Cross-verification with existing knowledge

Now, based on our knowledge of muscle physiology, we know that mitochondria in muscle cells convert chemical energy from food into a form that cells can use, ATP. And this process indeed requires oxygen (thus, making it an aerobic process). Therefore, the reason is scientifically accurate.

Checking Consistency Between Assertion and Reason

Checking if the assertion and reason align, we see that they do. The reason accurately explains why Red fibres are often referred to as aerobic muscles because of the role of mitochondria in using oxygen for ATP production in these fibres. Hence, both statements are correct and the reason is the right explanation for the assertion.

Key concepts

Aerobic Muscles

Aerobic muscles, commonly known as red muscle fibers, are specialized for endurance and sustained activities. These fibers are essential for exercises such as marathon running and cycling, where the muscles must work over extended periods without fatigue. This endurance capability is a result of aerobic metabolism, a process that uses oxygen to produce energy.

In our bodies, aerobic muscles have a rich supply of blood vessels and are packed with myoglobin, a protein that helps store and transport oxygen efficiently. This design allows these muscles to sustain prolonged activities by continuously producing energy.

Red muscle fibers play an integral role in everyday functions, enabling us to maintain posture and perform activities that require stamina. The capability of these muscles to work aerobically allows them to operate efficiently during long-lasting exertions.

Mitochondria

Mitochondria are often referred to as the "powerhouses" of cells due to their critical role in energy production. Found abundantly in aerobic muscles, they are responsible for converting nutrients into adenosine triphosphate (ATP), which is used as an energy source for cellular functions.

Within each mitochondrion, a series of complex reactions occur that break down glucose and fatty acids in the presence of oxygen to generate ATP. This process, known as oxidative phosphorylation, relies heavily on the availability of oxygen. Consequently, this underpins the necessity for the high concentration of mitochondria in red muscle fibers.

The abundance of mitochondria in aerobic muscles ensures that there is a continuous and efficient supply of energy, supporting prolonged physical activity. The more mitochondria present, the greater the muscle's capacity for aerobic energy production, reinforcing their capability to sustain activities for longer periods.

ATP Production

ATP, or adenosine triphosphate, is vital for energy transfer within cells. It acts as an energy currency that powers numerous cellular processes, including muscle contraction. In the context of red muscle fibers, ATP is produced primarily through aerobic respiration, a process facilitated by mitochondria.

During aerobic respiration, glucose and fatty acids are broken down in the presence of oxygen to produce ATP along with carbon dioxide and water. This process is highly efficient in energy production compared to anaerobic pathways, which do not require oxygen but generate less ATP.

For activities that require endurance and prolonged exertion, such as jogging or swimming, ATP produced aerobically is crucial. By ensuring a steady production of ATP, red muscle fibers can continue to contract efficiently and sustain activity over long durations without significant fatigue.

Muscle Physiology

Muscle physiology explores how muscles function, grow, and respond to training and exercise. An essential component of this is understanding the difference between the two primary types of muscle fibers: aerobic (red) and anaerobic (white).

Red muscle fibers are characterized by their endurance and ability to perform tasks over long durations. They rely on aerobic metabolism, which harnesses oxygen to produce ATP. White muscle fibers, on the other hand, are adapted for short bursts of power and speed, utilizing anaerobic metabolism.

In muscle physiology, knowing how different fibers respond to various stimuli and training regimens is crucial for optimizing performance and recovery. Muscles adapt over time to the types of exercises they undergo, increasing endurance, strength, or speed based on their function and predominant fiber type. Understanding these dynamics enables better training and conditioning strategies for athletes and individuals seeking to improve physical fitness.