AP Biology 2007-2008

Chemistry of Carbon

Building Blocks of Life

AP Biology

Why study Carbon?

All of life is built on carbon

Cells

~72% H2O

~25% carbon compounds

carbohydrates

lipids

proteins

nucleic acids

~3% salts

Na, Cl, K…

AP Biology

Chemistry of Life

Organic chemistry is the study of

carbon compounds.

All living things have carbon in it!

Therefore…all living things are organic!

C atoms are versatile building blocks

Very reactive atom.

Outer most shell needs four more

electrons to be full or stable.

Can form up to 4 stable covalent bonds

AP Biology

Let’s review the hierarchy of life

Atom

Element

Molecule

Organelle

Cell

Tissue

Organ

Organ system

Organism

Population

Community

Ecosystem

Biosphere

Whew! Glad you

didn’t forget that!

Did I mention this

will be on your

final exam in May?

AP Biology

We are adding 3 more!

Atom

Element

Molecule

Monomers

Polymers

Macromolecule

Organelle

Cell

Tissue

Organ

Organ system

Organism

Population

Community

Ecosystem

Biosphere

AP Biology

What is a monomer?

What does the

prefix “mono”

mean?

ONE!

A single (one unit)

that are building

blocks of larger

molecules.

LEGO?

LETTERS of the

alphabet?

B

I

O

I

S

F

U

N

AP Biology

What is a polymer?

What does the

prefix “poly”

mean?

MANY!

Polymers are many

monomers joined

together

MONO+MONO+MONO+MONO=POLY

LETTERS of the

alphabet?

Consider the previous

slide…

B

I

O

I

S

F

U

N

AP Biology

H2O

HO

HO H

H H HO

Polymers

Long molecules built by linking repeating

building blocks in a chain

monomers

Think individual legos!

building blocks

repeated small units

Held together by

covalent bonds

Dehydration synthesis

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Dehydration Synthesis or Condensation Reaction.

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H2O

HO

HO H

H H HO

How to build a polymer

Synthesis

joins monomers by “taking” H2O out

one monomer donates OH–

other monomer donates H+

together these form H2O

requires energy & enzymes

enzyme Dehydration synthesis

Condensation reaction

You gotta be open to “bonding!

AP Biology

Hydrolysis or Digestion

AP Biology

H2O

HO H

HO H HO H

How to break down a polymer

Digestion

use H2O to breakdown polymers

reverse of dehydration synthesis

cleave off one monomer at a time

H2O is split into H+ and OH–

H+ & OH– attach to ends

requires enzymes

releases energy

Breaking up is hard to do!

Hydrolysis

Digestion

enzyme

AP Biology

What is a macromolecule?

What does the prefix

“micro” mean?

SMALL

What does the prefix

“macro” mean?

LARGE!

Macromolecules are

many monomers and/or

polymers joined

together to form very

LARGE molecules.

AP Biology

BIO + IS + FUN = BIO IS FUN

Letters of the alphabet represent

monomers.

Letters combine to make words represent

monomers combining to make polymers.

Combing words to make sentences

represent combining polymers to make

macromolecules!

AP Biology 2007-2008

The 4 Macromolecules

Building Blocks

of Life

AP Biology

Macromolecules

Smaller organic molecules join together

to form larger molecules

macromolecules

4 major classes of

macromolecules:

carbohydrates

lipids

proteins

nucleic acids

AP Biology

Carbohydrates

AP Biology 2006-2007

OH

OH

H

H

HO

CH2OH

H

H

H

OH

O

Carbohydrates

energy

molecules

AP Biology

Carbohydrates

Carbohydrates are composed of C, H, O

carbo - hydr - ate

CH2O

(CH2O)x C6H12O6

Monomers: simple sugars (single

sugars) or monosacharride (prefix

mono=one & suffix saccharide = sugar ).

3 monosaccharides :

Glucose, fructose and galactose

sugar sugar sugar sugar sugar sugar sugar sugar

C6H12O6 (CH2O)x

AP Biology

Function:

Dietary energy energy storage

raw materials structural materials

ex: sugars, starches, cellulose

AP Biology

Sugars

Most names for sugars end in -ose

Classified by number of carbons

6C = hexose (glucose)

5C = pentose (ribose)

3C = triose (glyceraldehyde)

OH

OH

H

H

HO

CH2OH

H

H

H

OH

O

Glucose

H

OH

HO

O H

H HO

H

Ribose

CH2OH

Glyceraldehyde

H

H

H

H

OH

OH

O

C

C

C 6 5 3

AP Biology

More sugars!

Disaccharides = 2 sugars

Sucrose,

maltose,

lactose

Polysaccharides = many sugars

large polymers

Starch

Glycogen

Cellulose

Chitin

AP Biology

Building sugars

Dehydration synthesis

glycosidic linkage

The bond that joins

monosaccharides to create

polysaccharides

|

glucose

|

glucose

monosaccharides disaccharide

|

maltose

H2O

AP Biology

Building sugars

Dehydration synthesis

|

fructose

|

glucose

monosaccharides

| sucrose

(table sugar)

disaccharide

H2O

AP Biology

Polysaccharides

Polymers of sugars

costs little energy to build

easily reversible = release energy

Function:

energy storage starch (plants)

glycogen (animals) in liver & muscles

structure cellulose (plants)

chitin (arthropods & fungi)

AP Biology

Linear vs. branched polysaccharides

starch

(plant)

glycogen

(animal)

energy

storage

slow release

fast release

AP Biology

Polysaccharide diversity

Molecular structure determines function

isomers of glucose

structure determines function…

in starch in cellulose

AP Biology

Digesting starch vs. cellulose

starch easy to digest enzyme

enzyme

cellulose hard to digest

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Cellulose

Most abundant organic compound on Earth

herbivores have evolved a mechanism to digest cellulose

most carnivores have not that’s why they

eat meat to get their energy & nutrients

cellulose = undigestible roughage

AP Biology

Cow can digest cellulose well; no need to eat other sugars

Gorilla can’t digest cellulose well; must add another sugar source, like fruit to diet

AP Biology

Helpful bacteria

How can herbivores digest cellulose so well?

BACTERIA live in their digestive systems & help digest

cellulose-rich (grass) meals

AP Biology 2006-2007

Let’s build some

Carbohydrates!

EAT

X

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