Lecture 4 Flow Of Energy Flashcards
What is meant by the Flow of energy?
- How energy moves in and out, essential for life
- E harvested as chem energy in process converts H2O & CO2 to glucose
- O2 used to break down glucose releasing chem energy and heat in the process
Algae
- Mostly protists not plants
- Plant ancestor
- Very important for photosynthesis
1st Law of thermodynamics
Energy can be transformed but cannot be created or destroyed
- Sum of energy in system + surroundings = energy before transformation
2nd Law of Thermodynamics
Entropy constantly increases in a closed system.
If no energy leaves/ enters, potential energy of final state will always be > potential energy of initial state
Exergonic
Potential energy of products (final state) is < initial state
- Releases energy
- Energy out
Endergonic
Potential energy of products (final state) is > initial state
- Requires energy
- Energy in
Open System
Energy in from the surroundings and Energy out to the surroundings
Sunlight, O2, food in
CO2, waste products out
Closed system
No energy from the surroundings
Nothing in or out
Closed system: Order becomes disorder
Redox Reactions (Oxidized vs Reduced)
Atom losing e- oxidized (Reducing Agent)
Atom gaining e- reduced (Oxidizing Agent)
Oxidation
Losing e-
Reduction
Gaining e-
Enzymes
Speed up metabolism
Specialized as catalysts
Catalysts
Lowers activation energy
Allows for reactions to happen faster and in lower temperatures
Substrates
Molecules on which an enzyme acts
Active sites
Enzymes have active sites where reactions are catalyzed
Grooves where substrate fits precisely on the enzyme
Some enzymes require one or more non-protein components known as __, otherwise enzymes cannot function
Cofactors
3 Advantages of metabolic pathways
- Groups of enzyme involved in each can be segregated
- Little accumulation of intermediate products
- Any energy released will help drive reactions forward
Limits to enzyme action
- Availability of reactant molecules and/or cofactors
- Temperature affects enzymatic reactions
- pH influences enzyme activity
Regulatory enzymes
Will increase or decrease catalytic activity in response to substrate levels or signals
Allosteric enzymes
When regulator binds, it causes change in enzyme shape
Results in changes in substrate binding site & no longer works
The energy factor is known as
ATP
