energy enzymes and metabolism

• What are the two types of energy mentioned in the study material?

  Potential and kinetic energy
• How is energy defined in the context of biology?

  Energy is the ability to do work
• What does work refer to in the context of energy?


  Work refers to moving an object against an opposing force
• What are biological systems composed of?


  Cells, organisms, and ecosystems
• Why are biological systems considered the most complicated chemical systems?

  Because each chemical reaction relies on a change in energy
• How many chemical reactions are estimated to occur per cell in one second?


  Approximately 10^9 chemical reactions
• What is potential energy?


  Stored energy
• What is kinetic energy?


  Energy of motion
• What role do chemical bonds play in potential energy?


  Chemical bonds store potential energy
• How do stronger bonds compare to weaker bonds in terms of potential energy?


  Stronger bonds have lower potential energy than weaker bonds
• What happens to potential energy when more bonds are formed?


  More bonds result in more energy stored
• What is the difference between catabolic and anabolic reactions?


  Catabolic reactions release energy, while anabolic reactions require energy input
• What is the first law of thermodynamics?


  Energy is conserved
• What does the second law of thermodynamics state?


  Any transfer or transformation of energy increases the disorder of the universe
• What is entropy?


  Entropy is a measure of disorder
• How does entropy relate to biological systems?


  In biological systems, entropy manifests as heat and waste molecules
• What is free energy?


  Free energy is the usable energy in a chemical reaction
• How do cells maintain low entropy?


  Cells import usable energy and export waste products and heat
• What is an exergonic reaction?


  An exergonic reaction is spontaneous and releases energy
• What is an endergonic reaction?


  An endergonic reaction is not spontaneous and requires energy
• What is ATP?


  ATP stands for adenosine triphosphate
• What is the reaction for ATP hydrolysis?


  ATP + H2O → ADP + Pi + energy
• How much energy is released during ATP hydrolysis?


  7 kcal of energy
• What is the role of GTP in cells?


  GTP is used as an energy source in protein synthesis and signal transduction
• How do enzymes affect chemical reactions?


  Enzymes speed up reactions by lowering activation energy
• What is the active site of an enzyme?


  The active site is where the substrate binds and the chemical reaction occurs
• What is the induced fit model of enzyme action?


  The induced fit model describes how substrate binding changes the enzyme's structure to lower activation energy

  
• What happens to enzyme activity if the active site is altered?


  Enzyme activity will be reduced if the active site is altered
• What is denaturation in the context of enzymes?


  Denaturation is the breakdown of a protein's 3D structure
• How does substrate concentration affect enzyme activity?


  Increasing substrate concentration increases enzyme activity
• How does temperature affect enzyme activity?


  Temperature changes can alter the shape of the enzyme, affecting its activity
• What is the optimal pH for enzymes?


  Each enzyme has its own optimal pH based on its location in the organism
• What are the methods by which cells regulate enzyme function?

  Cells regulate enzyme function through genetic regulation, competitive inhibition, noncompetitive inhibition, and feedback inhibition
• What is feedback inhibition?


  Feedback inhibition occurs when the product of a reaction inhibits an enzyme in the pathway
• What are the types of metabolic reactions?


  • Anabolic reactions: build larger molecules from smaller ones, requiring energy
  • Catabolic reactions: break down larger molecules into smaller ones, releasing energy

  
• What is the significance of ATP in biochemical reactions?


  • ATP acts as the energy currency of the cell
  • ATP hydrolysis provides energy for endergonic reactions
  • ATP is constantly used and regenerated in cells
• What are the factors affecting enzyme activity?


  • Substrate concentration: higher concentration increases activity
  • Temperature: affects enzyme shape and activity
  • pH: each enzyme has an optimal pH for activity
• How do enzymes function in biochemical pathways?


  • Enzymes catalyze specific reactions in a pathway
  • Feedback inhibition regulates enzyme activity based on product levels
  • Enzymes lower activation energy to speed up reactions