Chapter 3: Energy, Catalysis, and Biosynthesis

metabolism

All of the chemical reactions that occur within an organism to survive, grow, and reproduce

catabolism

Metabolic pathways that break down molecules, releasing energy.

anabolism

Metabolic pathways that construct molecules, requiring energy.

food molecules are dissipated as

heat

heat is a product of

energy conversion

biological order is made possible by

the release of heat energy from cells

Second law of thermodynamics states that the

Every energy transfer or transformation increases the entropy of the universe.

movement toward disorder is

-spontaneous

-required input of energy to reverse it

entropy

A measure of disorder or randomness.

The greater the disorder the ________________ the entropy

greater

systems will change spontaneously towards

arrangements with greater entropy

the chemical rxns inside a cell must increase

the total entropy of the entire system: cell and enviornment

The first law of thermodynamics states that

energy cannot be created nor destroyed, the energy in the universe must always be the same

cells obtain energy by the

oxidization of organic molecules

What is usually produced of the oxidization of organic molecules

CO2 and H2O (cell respiration)

biosphere

the collection of living things on earth

Carbon atoms are continuously being

cycled through the biosphere

electrons power

chemical reactions (oxidization and reduction)

oxidization

removal of electrons

reduction

addition of electrons

enzymes can convert substrates to

products

a chemical reaction can only proceed if it results in a net increase in disorder

delta G < 0

SPONTANEOUS,

- energy is released,

-energetically favorable

delta G > 0

-NONSPONTANEOUS,

-needs energy input

-energetically unfavorable

enzymes help create biological order by

coupling energetically unfavorable (Positive G) and energeticslly favorable (negative G) whole entire net is negative

chemical reactions tend to proceed until

equilibrium and cannot change it