chapter 6: energy metabolism Flashcards
Thermodynamics
- branch of chemistry concerned with ___ changes
cells are governed by the laws of ___ and ___
energy, physics, chemistry
Energy
capacity to do ___
Two states:
1. kinetic - energy of ____
2. ____ - stored energy
many forms - mechanical, ____, sound, electric current, ____ or radioactivity
work, motion, potential, heat, light
____ is most convenient way of measuring energy
- 1___ = heat required to raise 1 gram of water 1 C
heat, calorie
- energy flows into the biological world from the ___
- ______ organisms capture this energy
- stored as ____ energy in chemical bonds
- breaking bonds between atoms require___; energy stored in chemical bonds may be used to make new bonds
sun, photosynthetic, energy
_____
- atom or molecule loses an electron
_______
- atom or molecule gains an electron
- higher level of ___ than oxidized form
_____
- reactions always paired
oxidation, reduction, energy, redox
first law of thermodynamics
- energy cannot be _______
- energy can only change from one form to another
- total amount of energy in the universe remains ____
- during each conversion, some energy is lost as ____
created or destroyed, constant, heat
second law of thermodynamics
- ____ (disorder) is continuously increasing
- energy transformations proceed _____ to convert matter from a more ordered/____ stable form to a less ordered/more stable form
entropy, spontaneously, less
Free energy
G= ___ available to do ____
G=H-TS
- H = ____, energy in a molecule’s chemical bonds
- T = absolute _____
- S = _____, unavailable energy
energy, work, enthalpy, temperature, entropy
change G = change H - TS
change G = change in ____ energy
positive change G
- products have ___ free energy than reactants
- H is ___ or S is ___
- Not _____, requires input of energy
- ____
negative change G
- products have ___ free energy than reactants
- H is ___ or S is ___ or both
- ______ (may not be ____)
- _____
free, higher, lower, spontaneous, endergonic, less, lower, higher, spontaneous, instantaneous, exergonic
Activation energy
extra energy required to ____ existing bonds and initiate a chemical reaction
rate of ____ reaction depends on the _____ energy required
- ____ activation energy proceeds more slowly
rate can be increased two ways:
1. ____ energy of reacting molecules (heating)
2. ____ activation energy
destabilize, exergonic, activation, larger, increasing, lowering
Catalysts
substances that influence ______ bonds in a way that ____ activation energy
cannot violate laws of ______
- cannot make an _____ reaction spontaneous
do not alter the proportion reactant turned into ____
chemical, lowers, thermodynamics, endergonic, product
ATP
_____
primary energy “currency” used by cells
composed of:
- ____ - five carbon sugar
- ____
- chain of ____ phosphates
- key to energy ____
- bonds are ___, release energy when broken
- ADP - ______ diphosphate = two phosphates
- AMP - _____ monophosphate = one phosphate - lowest energy form
adenosine triphosphate, ribose, adenine, three, storage, unstable, adenosine, adenosine
ATP cycle
ATP _____ drives ____ reactions
- coupled reaction results in net -__ (exergonic and spontaneous)
ATP not suitable for long-term energy ____
- phosphate bonds are too ___
- fats and carbohydrates better
- cells store only a few seconds worth of ____
hydrolysis, exergonic, G, storage, unstable, ATP
Enzymes: biological catalysts
most enzymes are ___
- some are ___
shape of enzyme stabilizes a temporary association between substrates
enzyme not changed or ___ in reaction
proteins, RNA, consumed
Active site
pockets or clefts for ___ binding
forms ____-____ complex
____ fit of substrate into active site
applies stress to distort particular bond to ____ activation energy
- ___ fit
substrate, enzyme substrate, precise, lower, induced
