To continue

Recall: In our study of biology

We are considering what I call:

LIVING SYSTEMS

Highly organized systems of

Matter and Energy

In our discussions then, we must

Consider the relation of

CHEMISTRY

to the patterns and processes of

LIVING SYSTEMS

The processes of chemisty

are actually rather

straightforward…

Here is chemistry in action!

But…what have

we here?

We will end the semester with this, the

Universe’s most complex

chemicalstructure, and the

“secret of life.”

It’s DNA

But the chemistry of a l.s.

requires us to consider certain

ELEMENTS and their

Chemical interactions

Here are most of

the elements!

But a l.s. does not concern

itself with every one of the

approximately 90 naturally

occurring elements…

Not this one…

This one…

Carbon, ol’ #6, is the “element of life,” and life is based on the

Chemistry of Carbon

So why ISCARBON

and itschemistry

the basis ofLiving Systems?

But, then, what is chemistry?

Let’s pause a moment and

ask a question…

The Purpose of Life is:

a. to use matter and energy

b. to survive and reproduce

c. to understand the Universe

d. to use chemical reactions

The Purpose of Life is:

a. to use matter and energy

b. to survive and reproduce

c. to understand the Universe

d. to use chemical reactions

But what was thatwe were sayingabout CHEMISTRY?

We are talking about

SPONCH and

the “Big C”

I’m a Woodchuck, and I’m full of SPONCH!

SPONCH?

The major ELEMENTS found

In Living Systems:

Sulfur, Phosphorus, Oxygen

Nitrogen, Carbon, Hydrogen

In order of abundance:

Hydrogen

Oxygen (A lot of H2O in a l.s.)

Carbon

Nitrogen

Phosphorus

Sulfur

SPONCH and somepals in a l.s.

Quick tour of Chemistry…

You know all about this, don’t you?

ISOTOPES—we’ll meet some of these later.Distinguish from ISOMERS, which we’ll meettoday.

Although there is only a handful of different kinds of

ELEMENTS in a living system,

There are millions of kinds ofMOLECULES

Let’s go from ATOMSto

MOLECULESvia a

CHEMICAL REACTION

This one

Hydrogen plus oxygen…

What’s that “Delta G” thingy?

It’s the “energy part” of a chemical reaction

A Chemical ReactionInvolves the

Making or

Breakingof bonds, which are

Electron RelationsBetween atoms

A Bond

Those bonds wereCOVALENT BONDS,

(shared pairs of electrons)but there are other kinds of

bonds that we can see in some molecules.

In particular, Water illustrates thekind of bond called aHYDROGEN BOND

And water is also involved in thechemical condition that

we call pH

Let’s pause for a moment…

A molecule is two or more atoms heldtogether by a/an:

a. exergonic relationb. chemical bondc. nuclear reactiond. elemental action

A molecule is two or more atoms heldtogether by a/an:

a. exergonic relationb. chemical bondc. nuclear reactiond. elemental action

When we look at living systems,from atom to organism,

we can view it in terms ofLevels of Structure

NIBMSEITLOE…

Life has evolved chemically,as well as structurally,

and all the chemical evolution isbased on the chemistry of

Carbon Molecules

Carbon molecules doing living things!

This is a fossil leaf, and the dark material

Is the carbon that made up itsorganic molecules…

The key element is Carbon

CARBON, Hooray!

ElementalCarbon asSOOT

ElementalCarbonAsGRAPHITE

Elemental Carbon asDIAMOND

But we are interested in CARBONWhich is in the form of ORGANIC MOLECULES

Here is a collection of aVariety of both Inorganic and

OrganicMolecules

And how do we build the thousands of

different organic molecules that we find in any living system?

I call it “building the Chemical Cathedral”

But METABOLISM consists ofTWO parts:

ANABOLISM—the “building up”of large molecules from

smaller ones.But also there is

CATABOLISM, the breakdown of larger moleculesinto smaller ones.

The breakdown process…

Hydrolysis is DOWNHILL towards

less structure, and theUniverse favors processes like this

over those in the direction of more structure

Let’s begin to lookat building up and breaking down

in relation toone of our classes of Organic Molecules,CARBOHYDRATES

The Basic Carbohydrate(for our purposes)

Is a hexose,A monosaccharide,A simple sugar…

GLUCOSE

But subtle differences in structure(ISOMERS)can producesugars of

different types

And there are other kinds of Sugars than Hexoses [6C]

We can find:

Trioses [3C]Pentoses [5C]

Let’s do a little“Cathedral Building”

We call this dehydration synthesis

So why ISCARBON

and itschemistry

the basis ofLiving Systems?

But, then, what is chemistry?

The Purpose of Life is:

a. to use matter and energy

b. to survive and reproduce

c. to understand the Universe

d. to use chemical reactions

The Purpose of Life is:

a. to use matter and energy

b. to survive and reproduce

c. to understand the Universe

d. to use chemical reactions

To be continued…