CH 8 Metabolism Lecture Mastery Flashcards
Definition of metabolism
All chemical and physical reactions within a cell that sustain life
All activities a cell or organism performs to move/transform energy and matter.
The word metabolism originates from Greek meaning
“change”
The purpose of ______ is :Cells require energy from the environment, which must be converted into a usable form for chemical reactions.
The purpose of metabolism
Eating food provides electrons (energy source) that are extracted during digestion and used to produce ATP (adenosine triphosphate), the cell’s energy currency.
This is an example of:
metabolism
Subcategories of Metabolism
Catabolism
Anabolism
Breaking down large substances into smaller ones.
* Example: Digesting food into smaller molecules.
*Subcategory of metabolism
Catabolism
Building larger substances from smaller ones.
* Example: Synthesizing proteins from amino acids.
Mechanisms: These processes occur via reactions like dehydration synthesis (building) and hydrolysis (breaking down).
*Subcategory of metabolism
Anabolism
3 Requirements for Metabolism
Energy: Powers cellular reactions
Enzymes: Proteins that facilitate chemical reactions
Nutrients/Raw Materials: Provide building blocks
______ is the ability to do work or cause change. Powers metabolism and cellular action.
______: Moving matter against opposing forces (e.g., getting out of bed).
Energy is the ability to do work or cause change. Powers metabolism and cellular action.
Work: Moving matter against opposing forces (e.g., getting out of bed).
2 Types of Energy
Potential Energy
Kinetic Energy
- ______: Stored energy, not currently in use.
(sub category) _____ Energy: Energy stored in chemical bonds (key in biology).
Bonds store energy from electrons, used to build cell structures or perform work.
potential
Chemical
- _________: Energy of motion, actively doing work.
* Thermal Energy (Heat): Energy released when molecules move (e.g., during bond breaking or formation).
Energy Transformation: Cells convert environmental energy (e.g., from food or sunlight) into usable forms like ATP.
Kinetic Energy
________: Study of energy transfer in systems.
_____ Systems: Exchange energy and matter with surroundings (focus in biology; e.g., cells, organism, population, community).
_____ Systems: Exchange energy but not matter (less relevant in biology).
______ Systems: Exchange neither energy nor matter (not applicable here).
Thermodynamics: Study of energy transfer in systems.
Open Systems: Exchange energy and matter with surroundings (focus in biology; e.g., cells, organism, population, community).
Closed Systems: Exchange energy but not matter (less relevant in biology).
Isolated Systems: Exchange neither energy nor matter (not applicable here).
First Law of Thermodynamics (Conservation of Energy):__________.
Example: Sunlight → chemical energy in plants → kinetic energy in animals.
Some energy is lost as_____ during each transfer, but total energy remains constant.
________(thermal energy) accounts for “lost” energy, ensuring conservation.
Energy cannot be created or destroyed, only transferred or transformed
heat, heat
Second Law of Thermodynamics (Entropy): ______________
_______: Measure of disorder; not inherently negative in biology.
Example: Diffusion of dye in water across a semipermeable membrane reaches equilibrium (equal distribution).
Equilibrium can be beneficial or problematic depending on context.
Eventually everything reaches equilibrium.
Every energy transfer increases entropy (disorder) in a system (universe).
Entropy
Without energy input, entropy __________.
_____ Entropy: Highly ordered system.
____ Entropy: Disordered system.
Living organisms resist excessive entropy to maintain order (e.g., through energy intake).
Without energy input, entropy increases over time.
Low Entropy: Highly ordered system.
High Entropy: Disordered system.
Living organisms resist excessive entropy to maintain order (e.g., through energy intake).
_______ Processes: Occur without additional energy input; increase entropy (disorder in the universe).
Example: A messy room naturally becomes messier (no energy required).
* Note: _______ doesn’t mean fast; it happens naturally over time.
Spontaneous
_______ Processes: Require energy input; decrease entropy (e.g., cleaning a room).
Non-Spontaneous
_______ (ΔG): measure of a systems stability
Amount of energy available for work in a system.
ΔG (Delta G): Change in free energy during a reaction.
High ΔG = ____ system;
Low ΔG = ____ system.
Organisms adjust ____ to maintain balance (not too much or too little).
Free Energy (ΔG): measure of a systems stability
Amount of energy available for work in a system.
ΔG (Delta G): Change in free energy during a reaction.
High ΔG = unstable system; Low ΔG = stable system.
Organisms adjust free energy to maintain balance (not too much or too little).
Chemical Reaction Types: Both are constantly used by living organisms to carry out homeostasis
1. ______ (Spontaneous):
Release energy; increase entropy; negative ΔG.
Example: Breaking down ATP.
2. _____ (Non-Spontaneous):
Require energy; decrease entropy; positive ΔG.
Example: Building ATP or proteins.
***Equilibrium:
Systems strive for stability; cells may promote or prevent equilibrium depending on needs.
Total equilibrium with surroundings = death; partial equilibriums (e.g., isotonic solutions) can be beneficial.
Chemical Reaction Types: Both are constantly used by living organisms to carry out homeostasis
1. Exergonic (Spontaneous):
Release energy; increase entropy; negative ΔG.
Example: Breaking down ATP.
2. Endergonic (Non-Spontaneous):
Require energy; decrease entropy; positive ΔG.
Example: Building ATP or proteins.
Equilibrium:
Systems strive for stability; cells may promote or prevent equilibrium depending on needs.
Total equilibrium with surroundings = death; partial equilibriums (e.g., isotonic solutions) can be beneficial.
_________ powers cellular reactions requiring energy.
Adenosine triphosphate (ATP) powers cellular reactions requiring energy.
Structure:
Adenine (nitrogenous base, also in DNA/RNA).
Ribose (sugar, also in RNA).
Three phosphate groups (store high potential energy in bonds).
ATP
Function:
Main energy currency of the cell
Provides energy for non spontaneous metabolic reactions
ATP
ATP cycle:
Cycle:
1._____ (Breakdown):
Spontaneous Process
ATP → ADP + Pi (inorganic phosphate) + energy.
Exergonic Releases energy (-ΔG)
Breaking the last phosphate bond releases energy for cellular work.
The breaking of phosphate bonds provide energy for other cellular reactions
2.____:
Non-Spontaneous Process
ADP + Pi + energy → ATP.
Energy from food (electrons) phosphorylates ADP to reform ATP.
Electrons brought in from the environment allow a phosphate to be added
Endergonic Requires energy input (+ΔG)
Cycle:
1. Hydrolysis (Breakdown):
Spontaneous Process
ATP → ADP + Pi (inorganic phosphate) + energy.
Breaking the last phosphate bond releases energy for cellular work.
The breaking of phosphate bonds provide energy for other cellular reactions
2. Regeneration:
Non-Spontaneous Process
ADP + Pi + energy → ATP.
Energy from food (electrons) phosphorylates ADP to reform ATP.
Electrons brought in from the environment allow a phosphate to be added
ATP is
Importance: Essential for non-spontaneous reactions (e.g., protein synthesis).
Universal: Used by all organisms (humans, bacteria, fungi, etc.).
Importance: Essential for non-spontaneous reactions (e.g., protein synthesis).
Universal: Used by all organisms (humans, bacteria, fungi, etc.).
Proteins that speed up or help metabolic reactions without being consumed (acts as a catalyst).
Enzymes
Role: They work by lowering the activation energy required for chemical or physical reactions, especially endergonic ones.
Reduce the amount of energy a cell needs for metabolism
Enzymes
Enzyme structure:
_______: Specific region where ______ bind for reactions.
_______: Reactants that fit into the ______.
Active Site (Catalytic Site): Specific region where substrates bind for reactions.
Substrates: Reactants that fit into the active site.
Enzymes Functions:
1. ______: Combine substrates into larger products (e.g., linking amino acids).
2. ______: Break down substrates into smaller products.
Enzymes Functions:
1. Synthesis: Combine substrates into larger products (e.g., linking amino acids).
2. Decomposition: Break down substrates into smaller products.
Enzymes are highly specific.
_______ Model: Substrate fits perfectly into an active site.
______ Model: Active site adjusts slightly to fit substrate, then releases products.
Enzymes are highly specific.
Lock-and-Key Model: Substrate fits perfectly into an active site.
Induced Fit Model: Active site adjusts slightly to fit substrate, then releases products.
