ENERGY TRANSFORMATION + UTILIZATION BY CELLS
Energy in a narrow sense = “Free Energy”
- Energy AVAILABLE to DO WORK
- G (Gibbs free energy)
G = H - TS
unusable
useable total
energy energy
energy (entropy)
(enthalpy)
- T = temperature (generally constant)
-
Change in Free Energy
- Endergonic Reaction (+ΔG)
ΔGreaction = ΔGproducts - ΔGreactants
→Catabolic
→Lower G products
→Increase entropy
→Spontaneous
- Exergonic Reaction (-ΔG)
ΔGreaction =
ΔGproducts - ΔGreactants
, →Anabolic
→Higher G products
→Decrease entropy
→Non- spontaneous
How do -ΔG reactions
happen?
→ by lowering activation energy,
which is done by ENZYMES!
How do +ΔG reactions
happen?
→ through REACTION
COUPLING! (mashing reactions
together)
→ “Makes a positive
delta G reaction into a net
negative delta G reaction”
→ Enzymes are still
needed!
→ ATP makes ADP and PI (extra phosphate floating around by itself)!
Energy in a narrow sense = “Free Energy”
- Energy AVAILABLE to DO WORK
- G (Gibbs free energy)
G = H - TS
unusable
useable total
energy energy
energy (entropy)
(enthalpy)
- T = temperature (generally constant)
-
Change in Free Energy
- Endergonic Reaction (+ΔG)
ΔGreaction = ΔGproducts - ΔGreactants
→Catabolic
→Lower G products
→Increase entropy
→Spontaneous
- Exergonic Reaction (-ΔG)
ΔGreaction =
ΔGproducts - ΔGreactants
, →Anabolic
→Higher G products
→Decrease entropy
→Non- spontaneous
How do -ΔG reactions
happen?
→ by lowering activation energy,
which is done by ENZYMES!
How do +ΔG reactions
happen?
→ through REACTION
COUPLING! (mashing reactions
together)
→ “Makes a positive
delta G reaction into a net
negative delta G reaction”
→ Enzymes are still
needed!
→ ATP makes ADP and PI (extra phosphate floating around by itself)!
