Everything! It is the foundation on which all biology is built.
A house that is not built on a firm foundation will soon crumble.
If you ignore or don't understand chemistry your understanding of biology will be superficial and weak.
A little story will illustrate this point…
Sigmund Freud's Fall from Grace
The Rise and Fall of Freudianism
Freud, the founder of psychoanalysis, is the thinker whose work suffered the greatest rise and fall from grace in the 20th century.
He “rocked” the scientific world with the publication, in 1900, of his revolutionary book The Intrepretation of Dreams.
By mid-century he was universally esteemed in the West as the man who had uncovered the deepest truths about human motivation and desire.
He believed that mental illnesses, including serious diseases like manic depression and schizophrenia, were primarily psychological in nature.
These illnesses could best be cured through “talk therapy.”
But by the end of the century, Freud was regarded by most of the medical profession as little more than a footnote in intellectual history, someone who was more of a philosopher than a scientist.
John Cade Changes the World
In 1949, the Australian psychiatrist John Cade made a discovery that would marginalize Freud and his ideas.
He miraculously cured some of his manic-depressive patients by administering the drug lithium.
By the end of the century Freud's “talk therapy” had been replaced by Cade's “drug therapy.”
A slew of drugs have been developed over the last fifty years that affect the brain.
The success of anti-depressants has been phenomenal: Prozac, Zoloft, Paxil, etc.
Over 28 million Americans have taken Prozac (10 % of the US population).
Ask anyone who has taken these drugs—it is like night and day…
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Freudianism vs. Biochemistry
How to Think of Freudianism: A Fitting Analogy
Freud's theory of how the brain works in controlling human behavior is similar to a situation in which a group of primitive tribesmen find a working automobile and try to develop a theory to explain how it works without being able to open the hood.
They would observe a strong corrleation between stepping on the gas pedal and moving forward.
They might theorize that there was some device connecting the two that converted a force into motion of wheels—perhaps a large squirrel in a cage.
They would have no understanding of hydrocarbons, internal combustion, valves, or pistons—all the things that actually do the energy conversion.
The Triumph of Biochemistry
Unlike Freud's theory of the unconscious, which makes speculative, unprovable claims about how the mind works, biochemistry allows us to lift the hood and peer—however tentatively—into the internal workings of the brain.
We have discovered that a dozen or so neurotransmitters such as serotonin, dopamine, and norepinephrine control the firing of nerve synapses and the transmission of signals across the neurons in the brain.
The levels of these neurotransmitters and the way they interact directly affect our subjective feelings of well being, self-esteem, fear, and so on.
Conceptual Biochemistry: How the Synapse Functions
