Energy And Enzymes Flashcards
What is bioenergetics?
The study of energy flow through biological systems
Bioenergetics explores how energy is transformed and utilized in living organisms.
What is metabolism?
Enzymatically-driven processes
Metabolism encompasses all chemical reactions in living organisms that maintain life.
What are the two main types of metabolism?
- Anabolism
- Catabolism
Anabolism involves building complex molecules, while catabolism involves breaking down molecules for energy.
Define anabolism.
Building complex molecules (e.g., photosynthesis, lipid synthesis)
Anabolism is crucial for growth and repair in organisms.
Define catabolism.
Breaking down molecules for energy (e.g., glycolysis, cellular respiration)
Catabolism releases energy stored in complex molecules.
What is potential energy?
Stored energy (e.g., chemical bonds)
Potential energy is the energy held by an object because of its position or state.
What is kinetic energy?
Energy of motion (e.g., molecular movement)
Kinetic energy is the energy an object possesses due to its movement.
What does the First Law of Thermodynamics state?
Energy cannot be created or destroyed but can transform or transfer.
How do biological systems interact with their surroundings according to the First Law of Thermodynamics?
Biological systems are open systems, exchanging energy and matter with their surroundings.
What is the Second Law of Thermodynamics?
Systems naturally move towards disorder (increased entropy).
How do biological systems maintain order in relation to the Second Law of Thermodynamics?
Biological systems maintain order but increase entropy in their surroundings due to heat loss.
Fill in the blank: The First Law of Thermodynamics states that energy cannot be created or destroyed but can _______.
[transform or transfer]
True or False: Biological systems are considered closed systems according to the First Law of Thermodynamics.
False
True or False: The Second Law of Thermodynamics implies that biological systems can create order without increasing entropy elsewhere.
False
What does Gibbs Free Energy (AG) measure?
The energy available to do work.
What characterizes exergonic processes?
They release energy (negative AG).
What are two examples of exergonic processes?
- Diffusion
- ATP hydrolysis
What characterizes endergonic processes?
They require energy input (positive AG).
What are two examples of endergonic processes?
- Active transport
- Biosynthesis
What is energy coupling?
Combines exergonic reactions with endergonic reactions to drive biological processes.
What is the primary role of enzymes?
Lower the activation energy of a reaction to speed it up.
What mechanism do enzymes use to stabilize substrates?
Stabilize substrates in the transition state.
What is one way enzymes facilitate reactions?
Bring substrates together in correct orientations.
How do enzymes induce strain to facilitate breaking bonds?
Induce strain in specific bonds.
What do enzymes create in the active site to assist in reactions?
A distribution of electrical charges.
Name the two models of enzyme function.
- Lock-and-Key
- Induced Fit
True or False: The Lock-and-Key model is considered accurate.
False.
Describe the Induced Fit model.
The enzyme and substrate undergo conformational changes for a better fit.
Fill in the blank: The enzyme’s active site has a _______ shape complementary to the substrate.
[fixed]
What factor increases enzyme activity up to an optimal point before denaturation occurs?
Temperature
Denaturation refers to the structural alteration of the enzyme, leading to loss of function.
What is the optimal condition for enzyme function regarding pH?
Enzymes function best at their environmental pH optima.
Each enzyme has a specific pH range in which it is most active.
How do higher substrate or enzyme levels affect reaction rates?
They increase reaction rates until saturation.
Saturation occurs when all active sites of the enzyme are occupied.
What are competitive inhibitors?
They compete for the active site.
This type of inhibition can be overcome by increasing substrate concentration.
What are non-competitive inhibitors?
They bind elsewhere, altering enzyme function.
Non-competitive inhibition cannot be overcome by increasing substrate concentration.
What does ATP stand for?
Adenosine Triphosphate
ATP is known as the universal energy currency of the cell.
How is ATP regenerated?
From ADP + Pi.
This process is vital for maintaining energy levels in cells.
What is released during the hydrolysis of ATP?
Energy (-7.1 kcal/mol) used in cellular work.
Hydrolysis of ATP is a key reaction in energy metabolism.
