Chapter 1e - Bioenergetics and Metabolism Flashcards
What is bioenergetics? What does it refer to?
Bioenergetics refers to the flow of energy within a biological system and is primarily focused on how macronutrients, containing chemical energy, from food (carbs, fats, proteins) are converted into biologically usable forms of energy to perform work.
What is catabolism and what is anabolism?
Catabolism - The process of breaking large molecules into smaller molecules to make energy available to the organism. Ex - Carbs are catabolized for fuel for exercise and normal physiological process. Can also involve the breakdown of muscle tissue during the periods of heavy training volume, low caloric intake?
Anabolism - Anabolism is the process of restructuring or building larger compounds from catabolized materials, such as assembling amino acids into structural proteins.
What’s an exergonic reaction vs an endergonic reaction?
Exergonic - chemical reactions that result in the release of energy from the system, which can then be used to perform work. These reactions are spontaneous and favorable.
Endergonic reaction - A type of chemical reaction that requires the input of energy. In the body, the energy comes in the form of the ATP (adenosine triphosphate). These reactions are NOT spontaenous and are typically involved within anabolic processes.
Explain Metabolism?
It is the sum total of all catabolic and anabolic reactions in the human body that are occurring. This continuously occurs. Physiological processes such as muscle growth and hormone balance rely on these reactions and continuously occur for homeostasis. You can calculate metabolic rate.
Explain ATP , what’s it for, how is it replenished.
ATP is a high energy molecule used for muscle contraction, movement and other life sustaining metabolic processes. ATP is an intermediate molecule that allows energy to transfer from exergonic to endergonic and catabolic to anabolic reactions. ATP is generated and replenished in skeletal muscle by three energy systems: phosphagen, glycolytic and oxidative.
Explain what ATP Hydrolysis is? How is ATPase involved.
Hydrolysis is a general term for any chemical reaction that breaks the chemical bond via the addition of water. ATP hydrolysis splits the ATP molecule into adenosine diphosphate (ADP) and usable energy. ATPase is the catalyst for the hydrolysis of ATP.
What’s the ATP hydrolysis equation?
ATP + H2O <– ATPase –> ADP + P + H+ + Energy
How is ADP Adenosine Diphosphate produced?
When ATP undergoes hydrolysis, ADP, an inorganic phosphate molecule, a hyrdrogen ion, and free energy are produced.
What’s ATPase?
The enzyme that is responsible for catalyzing the breakdown of ATP to ADP. The dephosphorylation reaction results in the release of energy used to carry out other chemical reactions.
Myosin ATPase vs Calcium ATPase and Sodium Potassium ATPase.
Myosin ATPase - Myosin ATPase catalyzes ATP hydrolysis, providing the energy for cross-bridge recycling.
Calcium ATPase - The enzyme that provides the energy used to regulate calcium movement by pumping into the sarcoplasmic reticulum
Sodium ATpase - Enzyme that controls the sodium potassium concentration gradient in the sarcolemma after depolarization to maintain the cellular resting potential.
Adenosine Monophosphate?
AMP results from ADP hydrolysis, which leaves the second phosphate group, leaving one.
What are the biological energy systems in muscle cells that can replace ATP? Which occur in the sarcoplasm and which occur in the mitochondria?
Phosphagen system , Glycolytic system. Electric transport chain (ETC) and Krebs cycle are aerobic mechanisms that require oxygen and occur in the mitochondria.
What is the phosphagen system?Is it an early or late system, for aerobic or anaerobic exercises, etc.
Phosphagen system uses ATP hydrolysis for high-intensity activities of short length ( eg - resistance training, short and intense sprints, and other vigorous bouts that last about 10 sec in duration. It’s active at the start of all activities until other systems have time to start producing energy. Relies on the breakdown of creatine phosphate and CP stores to maintain ATP concentration. After 10 sec glycolytic system contributes to energy.
What’s found more CP or ATP in muscle. More in type I or Type 2. What’s the reaction. Creatine Kinase ?
CP is found 4-6x more in muscle compared to ATP. CP is higher in type II than type I.
ADP + CP <– Creatine Kinase –> ATP + Creatine
CK needed for catalyze
Note: Elevated levels of Creatine Kinase in blood serum are indicates of muscle damage (kidney failure or heart attack). Too much work performed in a training session can cause rhabdomyolysis - the rapid breakdown of muscles, elevating levels of CK in blood serum
Explain the glycolytic system? How does it compare to phosphate for energy usage.
Glycolysis is the breakdown of glucose to replenish ATP. Glucose comes directly out of blood circulation or is broken down from glycogen stores in the muscle or liver, or is converted from other substrates. ATP replenished during glycolysis is slower compared to phosphagen system due to more steps. Glycolysis produces more ATP than phosphate due to to large supply of glucose and glycogen in the body vs compared to limites creatine phosphate
