The Chemistry of
Life
Properties of water
 Polar~ opposite ends, opposite
charges
 Cohesion~ water sticks to water
 Adhesion~ water sticks to something
else
 Capillary Action ~ Cohesion PLUS
Adhesion… how water moves UP a
plant
Water
Surface tension
 (high) Specific heat
 (high) Heat of vaporization
 Density: Ice is LESS DENSE than liquid
water… why ice floats! Due to H bonding

Organic Compounds
 Contain CARBON
 In science terms, organic
means carbon-containing
 Are
POLYMERS*
Polymers
are
composed of
monomers

*Lipids are not polymers… are not
composed of monomers.
Polymer
Mono = one
 Poly = many


Polymers are to macaroni necklaces as
monomers are to macaroni
polymer
monomer
Huh?

Carbs, Proteins,
and Nucleic
Acids are all
made up of
repeating
subunits.

Lipids are a
special case
Carbohydrates

Examples:

Sugars (simple carbs) and starches (complex
carbs)
 Glucose,
fructose, sucrose, ribose, deoxyribose,
cellulose, potatoes, pastas, glycogen (how animals
store energy)
Carbohydrates

structure = Rings or long chains of rings
Carbohydrates

Elements:


Carbon, Hydrogen ,Oxygen – CHO
H:O ratio = 2:1
For every 2 H’s, there is one O
 Glucose = C6H12O6… 12:6 = 2:1
 Cellulose = (C6H10O5)n… 10:5 = 2:1

Carbohydrates

Monomer: monosaccharide
Mono = ONE
 Di = TWO
 Poly = MANY

Sucrose is a disaccharide made of
glucose PLUS fructose
 Cellulose is a polysaccharide made of up
to 10,000 connected D-glucose molecules

Carbohydrates

FUNCTION: quick energy

Sugars = simple  very quick energy
 Ex:

OJ if blood sugar is low
Starches = complex carbohydrate  takes
longer for body to break down… longer term
energy source
 Ex:
Before a football game, eat pasta or cereal
Lipids

Examples: Fats, oils, waxes, steroids, fatsoluble vitamins (A, D, K, E), triglycerides,
cholesterol

Butter, olive oil, cell membranes
(phospholipids)
Lipids

Structure: 2 or 3 long H-C tails
Lipids

Elements: CHO


Carbon, Hydrogen, Oxygen
H:O ratio is >2:1

Ex: Vitamin E (tocopherol) = C29H50O2 so the
H:O ratio = 50:2 = 25:1 which is GREATER
THAN 2:1
Lipids

Monomer: Not Applicable (N/A)

Most lipids have a glycerol or carboxylic acid
“head” and fatty acid “tails”… so they all more
or less look alike, but no official monomer.
Lipids

Function: Long term energy storage

Ex: The human body converts excess glucose
(sugar) into fat.
What’s wrong with this picture?
Carbs vs. Lipids
BOTH have CHO
 BOTH store energy

Carbs: quick energy
 Lipids: long term energy  storage
 Excess carbs get turned into fat for storage


How can you differentiate between carbs
and lipids???
Carbohydrate or Lipid?

Formula: C18H34O2
Carbohydrate or Lipid?

Formula = C12H22O11
Carbohydrate or Lipid?

Formula: C27H46O
Carbohydrate or Lipid?

Formula: C12H24O2
Carbohydrate or Lipid?

Formula: C6H10O5
Proteins
Examples: Insulin, keratin, casein,
ENZYMES (catalase, amylase, lactase…)
 Found in meats, dairy products, eggs, and
some plants (nuts, lentils, and legumes
such as beans, peas, soy…)

Proteins

Structure: complex chain of linked amino
acids (peptide bond links AA’s)

polypeptide = precursor to protein
Proteins

Elements: CHON (sometimes S)


Carbon, Hydrogen, Oxygen, NITROGEN
(complex proteins have disulfide bridges…
hence Sulfur)
H:O ratio – N/A
Proteins
Monomer: AMINO ACIDS
 A long chain of AA’s = a polypeptide…
why?


Peptide bonds connect AA’s
Proteins are just folded polypeptides
 Proteins are made of…

20 essential amino acids
AA’s connected by peptide bond
Proteins

Function: structure (actin, chitin),
catalyzing reactions (enzymes lower
activation energy), repair and maintenance
Nucleic Acids

Examples: DNA, RNA (tRNA, mRNA,
rRNA)… NA stands for Nucleic Acid

Found in ALL LIVING THINGS!!
In the NUCLEUS of eukaryotes (protists,
fungi, plants, animals)
 Free-floating in prokaryotes (bacteria)

Nucleic Acids
Structure: single stranded (RNA) or double
stranded (DNA)
 DNA: ATCG
 RNA: AUCG

Nucleic Acids
Elements: CHONP
 Carbon, Hydrogen, Oxygen, Nitrogen,
PHOSPHORUS


H:O ratio: N/A
Nucleic Acids

Monomer: Nucleotide

Nucleotide = phosphate group, nitrogen base,
5-carbon sugar
 Phosphate
group : P
 Nitrogen base: N

5
A, T, C, G, U (RNA only)
Carbon sugar: CHO


Sugar is a carb… CHO
Deoxyribose or ribose
Nucleic Acids

Function: Heredity
Stores ALL genetic information
 Codes for proteins responsible for
expressed traits

Carb, Lipid, Protein, or Nucleic Acid?
Provides rigid structure for plant cells
 Made of long chain of monosaccharides

Carb, Lipid, Protein, or Nucleic Acid?
Genes are made of this
 Long, complex molecule containing
CHONP

Carb, Lipid, Protein, or Nucleic Acid?

Main component of cell membranes
Carb, Lipid, Protein, or Nucleic Acid?

Monomer: nucleotide
Carb, Lipid, Protein, or Nucleic Acid?
Amino Acids are connected by peptide
bonds
 This macromolecule is HUGE and
complex

Carb, Lipid, Protein, or Nucleic Acid?
Simple ones end in –ose
 Complex ones are broken down to simple
ones to power cellular respiration (and
make ATP)


That’s why you eat!!!
Carb, Lipid, Protein, or Nucleic Acid?
Elements: CHO
 H:O ratio is >2:1

Enzymes

Enzymes are
PROTEINS
 Biological catalysts

 Speed
up chemical reactions by lowering
activation energy
Substrate-specific (like a lock and a key)
 Reusable
 Ends in –ase
 Affected by temperature and pH

Enzymes

Proteins
Enzymes:
 Bind to substrate (molecule it acts on)
 Are specific (binds to certain substrate)
 Has active site (where substrate binds)
 Are reusable
 Are affected by temperature and pH
 Are PROTEINS
Metabolism – all chemical reactions in a
biological system
 Catabolism – breakdown of substances
 Anabolism – formation of new products

Catabolic Enzyme
Anabolic Enzyme
Enzymes
Speed up rxns (catalyze rxns) by lowering
activation energy
 Higher concentration of enzyme = faster
reaction

Factors
Affecting
Enzyme
Activity
In Review:Enzymes
Substrate-specific (like a lock and key)
 Reusable
 End in -ase

Crash Course

Biomolecules

Enzyme song video