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Notes on Cellular Respiration/Photosynthesis

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Notes on Cellular Respiration/Photosynthesis

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Chapter 6-Intro to Metabolism
METABOLISM= all the chemical reactions in an organism
CATABOLIC PATHWAY (CATABOLISM)• release of energy by the breakdown of complex molecules to simpler compounds

EX: digestive enzymes break down food
ANABOLIC PATHWAY (ANABOLISM)
• consumes energy to build complicated molecules from simpler ones

EX: linking amino acids to form proteins
ORGANISMS TRANSFORM ENERGY
ENERGY- capacity to do work
KINETIC ENERGY- energy of moving objects
POTENTIAL ENERGY- energy stored as a result of position or structure CHEMICAL ENERGY- form of potential energy stored in chemical bonds in molecules THERMODYNAMICS- study of energy transformations that occur in matter 1st LAW OF THERMODYNAMICS = Conservation of energy

• energy of universe is constant; energy CAN BE transferred and transformed, but NEVER created or destroyed

2nd LAW OF THERMODYNAMICS
• every energy transfer or transformation increases the entropy (disorder or randomness) in universe

Equation that describes energy of system;

G= H-T S
- change in free energy is represented by  G
S = ENTROPY
G = FREE ENERGY of a system
(energy that is able to perform work when the temperature is uniform) H = Total energy in system
T = Absolute temperature in °Kelvin

You don’t need to be able to
do G problems; just know
that there is an equation;

EXERGONIC REACTION- releases energy and occurs spontaneously Energy of products is lower than energy of reactants (negative G) ENDERGONIC REACTION- requires energy; absorbs free energy from system; not spontaneous Energy of products is higher than energy of reactants (positive G) SPONTANEOUS REACTION

- can occur without outside help
- can be harnessed to do work (objects moving down their power gradient) Cells manage their energy resources and do work by ENERGY COUPLING (use energy from exergonic reactions to drive endergonic ones) Key role of ATP = ENERGY COUPLING

ADENOSINE TRIPHOSPHATE (ATP)
= primary source of energy in...