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Introduction to Metabolism - Coggle Diagram
Introduction to Metabolism
Organism's Metabolism
Metabolism
Definition: Sum of an organisms chemical reactions
Metabolic Pathways
Definition: A series of steps, catalyzed by a specific enzyme
Catabolic Pathways
Function: Break down complex molecules
Energy: Release Energy(exergonic
Example: Cellular Respiration(glucose breakdown)
Anabolic Pathway
Function: Build complex molecules
Energy: Consume energy(Endergonic)
Example: Protein synthesis from amino acids
Forms of Energy
Definition: The capacity to cause change
Kinetic Energy
Definition: Energy of stored motion
Sub type: Thermal Energy(Heat)
Definition: Kinetic energy from random molecule movement
Potential Energy
Definition: Stored energy
Basis: Location or Structure
Sub type: Chemical Energy
Definition: Potential energy stored in chemical bonds
Free Energy Change of a Reaction
Thermodynamics
Definition: Study of energy transformations
Organisms: Open systems( exchange energy with surroundings)
Laws of Thermodynamics
First Law
Concept: Conservation of Energy
Rule: Energy cannot be created or destroyed
Second Law
Concept: Entropy
Rule: Every energy transfer increases the universe's entropy
Life: Organisms increase surrounding entropy to maintain their own internal order
Gibbs Free Energy
Definition: Energy available to do work
Changes in Free Energy
Exergonic Reaction
(change)G: Negative
Process: Spontaneous
Energy; Net release of free energy
Endergonic Reaction
(Change)G: Positive
Process: Non-spontaneous
Energy: Requires an input of energy
Equilibrium
(Change)G: Zero
State: Maximum stability
no work can be done
ATP Powers Cellular Work
ATP(Adenosine Triphosphate)
Role
The cell's primary energy shuttle
Structure
Adenine(Nitrogenous base)
Ribose(Sugar)
Three Phosphate Groups
Energy Release(Hydrolysis)
Mechanism
Breaking the bond of the terminal phosphate
Reaction
ATP+H20-> ADP+ Inorganic Phosphate(Pi)+Energy
Why?
High potential energy from negative phosphate charges repulsing
Energy Coupling
Definition
Using exergonic process to drive an endergonic one
Mechanism
Phosphorylated Intermediate
Process: ATP transfers a phosphate to another molecule other than make it more reactive
Type of Cellular Work Powered by ATP
Chemical Work
Transport Work
Mechanical work
ATP Regeneration
Process
Anabolic(Endergonic
Reaction
ADP+Pi-> ATP
Energy Source
Catabolic Reaction
Enzymes Speed up Metabolic Reactions
Enzymes
Definition
A biological catalyst
Structure
Typically proteins
Function
Speeds up a reaction without being consumed
Nomenclature
Often end in "-ase"
Example: Sucrase
Activation Energy
Definition
The initial energy needed to start a reaction
Enzyme's Role
Lowers the activation energy
Key Point
Does not change the overall (Change)G of the reaction
Enzyme Substrate Interaction
Substrate
The specific reactant an enzyme acts on
Active Site
The region on the enzyme where the substrate binds
Specificity
Shape of active site is specific to its substrate
Induced Fit
Enzyme changes shape slightly to bind the substrate more securely
Factors Affecting Enzyme Activity
Environmental Factors
Temperature
Has an optimal range
high temperatures can cause denaturation
pH
Has an optimal range
extremes can cause denaturation
Example: Pepsin, optimal pH 2
Example: Trypsin, optima pH 8
Cofactors
Definition: Nonprotein helpers
Types
Inorganic
Minerals
Example: Iron and Zinc
Organic
Vitamins
Example: B Vitamins
Enzyme Inhibition
Competitive Inhibitors
Mechanism: Mimic the substrate and bind to the active site, resulting in blocking it
Noncompetitive Inhibitors
Mechanism
Bind to an allosteric site
Different part of enzyme
Effect
Causes the active site to chanege shape, making it less effective
Feedback Inhibition
Definition
The end product of a metabolic pathway that shuts down that same pathway
Mechanism
End product acts as an inhibitor for an early enzyme
Purpose
Prevents wasting resources
Avoiding overproduction