September 11, 2023 Flashcards
What are ATPases
are a class of enzymes that breakdown ATP to provide useful cellular energy
what is catabolism
refers to the break down complex molecules into simpler ones, releasing energy in the process
what is the job of metabolism
Energy Production: Metabolism’s most well-known role is to generate energy. It breaks down molecules like carbohydrates, fats, and proteins to release energy in the form of adenosine triphosphate (ATP).
This energy is used for various cellular processes, including muscle contraction, active transport of molecules, and the synthesis of other molecules.
what system takes care of the immediate source of energy
ATP-PC system
ATP-Phosphocreatine system
what is ATP-PCr
ATP-PCr, or adenosine triphosphate-phosphocreatine system, is a system within the body that plays a crucial role in providing short bursts of energy during high-intensity, short-duration activities, such as sprinting, weightlifting, and jumping.
It is one of the energy systems used by muscle cells to regenerate adenosine triphosphate (ATP), which is the primary molecule that provides energy for cellular processes.
how does the ATP-PC system work during exercise
Calcium indirectly activates Myosin ATPase
Phosphocreatine and ADP combine together to form Creatine and ATP (this is done with the enzyme Creatine Phosphokinase (CPK)
What is the role of Creatine Phosphokinase
CPK plays a crucial role in energy metabolism, particularly in the transfer and regulation of phosphate groups between molecules involving creatine.
where can Creatine Phosphokinase be found
an enzyme found in various tissues of the body, with the highest concentrations found in muscles and the brain.
How does the ATP-PC system work during recovery from exercise
Once you stop exercises, there is no more calcium to activate Myosin ATPase, which means ATP is not being broken down
ATP from the mitochondria mixed with creatine push the reaction back in the other direction
This causes phosphocreatine to go back up to resting levels
what activates myosin ATPase
Calcium Ion Release: Muscle contraction is initiated by the release of calcium ions (Ca2+) from the sarcoplasmic reticulum, a specialized organelle in muscle cells. When an action potential (nerve impulse) reaches the muscle cell, it triggers the release of calcium ions into the muscle cell’s cytoplasm.
single celled myoblasts →
multi-nucleated myotubes →
Muscle cells →
Muscle fibres →
Myofibres
Single fibres constrain myofibrils and have resident satellite cells which help to regenerate muscle
Myofibrils consist of
repeating sarcomeres with sarcoplasmic reticulum
Sarcomere:
the contractile unit; z-line; thick filament; thin filament
what is excitation-contraction coupling in skeletal muscle
Excitation-contraction coupling is the process by which a muscle cell (muscle fiber) is stimulated to contract