Chapter 8-Part 2 PicturesThermodynamics and ATP

Theoretical metabolic pathway

Enzyme 1 Enzyme 2 Enzyme 3A B C D

Reaction 1 Reaction 2 Reaction 3Startingmolecule

Product

Fig 5.2. Catabolic vs. Anabolic Reactions

• Condensation → reactions (anabolic)

• Hydrolysis → reactions (catabolic)

• Catabolic Rxns – • O-O O + O + Energy

• Anabolic Rxns-O + O + Energy O-O

Figure 8.6

In exergonic rxns∆G is a negative

number

ALL rxns require some input of energy

Fig 8.14 Energy Profile for a Catabolic (Exergonic) Reaction

∆G = ∆H - T∆S∆G = T∆S

Diffusion – spontaneous because randomness (disorder) increases (+∆S)

Catabolic Reaction – Spontaneous becausethermal energy (heat) is released (-∆H) AND bonds in products are more disordered (+∆S)

Examples of Stored energy (Potential energy)

Examples of Kinetic energy (Energy of Motion)

∆G values

• sucrose + H20 fructose + glucose (∆G = -7.0 kcal/mol)

Exergonic Reactions are Spontaneous

• What do we mean by spontaneous?

Example 1: Baking soda + vinegar (fast reaction)

fructose + glucose

Example 2: Sucrose hydrolysis (very slow reaction without a catalyst)

Spontaneous reactions are not time-dependent

Question 8.3 – 8.4

Fig 8.14 Energy Profile for an Exergonic Reaction

On the platform, a diverhas more potential energy.

Diving converts potentialenergy to kinetic energy.

Climbing up converts kineticenergy of muscle movement to potential energy.

In the water, a diver has less potential energy.

Figure 8.2

Figure 8.3 

First law of thermodynamics: Energy can be transferred or transformed but Neither created nor destroyed. For example, the chemical (potential) energy in food will be converted to the kinetic energy of the cheetah’s movement in (b).

(a)

Chemicalenergy

Figure 8.3 

Second law of thermodynamics: Every energy transfer or transformation increasesthe disorder (entropy) of the universe. For example, disorder is added to the cheetah’ssurroundings in the form of heat and the small molecules that are the by-productsof metabolism.

(b)

Heat co2

H2O+

50µm

Figure 8.4

Chemical Equilibrium

An organism in metabolic equilibrium

Equilibrium

ATP

ATP

Metabolic Disequilibrium

ATPATP

Food

Waste Products

Questions 8.5 – 8.6

ATP = Currency of the Cell

Fig 8.11

Fig 8.9 ATP hydrolysis

Coupled Reactions

Fig 8.10ATP hydrolysis

ATP synthesis

Question 8.7