The Chemistry of Life

Water

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

Surface tension (high) Specific heat (high) Heat of vaporizationDensity: Ice is LESS DENSE than liquid

water… why ice floats! Due to H bonding

Organic CompoundsContain CARBON In science terms, organic

means carbon-containing

Are POLYMERS*Polymers are

composed of monomers

*Lipids are not polymers… are not composed of monomers.

PolymerMono = onePoly = 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 = 2:1For every 2 H’s, there is one OGlucose = C6H12O6… 12:6 = 2:1

Cellulose = (C6H10O5)n… 10:5 = 2:1

Carbohydrates

Monomer: monosaccharideMono = ONEDi = TWOPoly = 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 energySugars = 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, fat-soluble vitamins (A, D, K, E), triglycerides, cholesterolButter, olive oil, cell membranes

(phospholipids)

Lipids

Structure: 2 or 3 long H-C tails

Lipids

Elements: CHOCarbon, Hydrogen, Oxygen

H:O ratio is >2:1Ex: 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 storageEx: The human body converts excess glucose

(sugar) into fat.

What’s wrong with this picture?

Carbs vs. Lipids

BOTH have CHOBOTH store energy

Carbs: quick energyLipids: long term energy storageExcess carbs get turned into fat for storage

How can you differentiate between carbs and lipids???

H:O RATIOMOLECULAR STRUCTURE

Carbohydrate or Lipid?

Formula: C18H34O2

Lipid: Oleic Acid

Carbohydrate or Lipid?

Formula = C12H22O11

Carb: Sucrose (table sugar)

Carbohydrate or Lipid?

Formula: C27H46O

Lipid: Cholesterol

Carbohydrate or Lipid?

Formula: C12H24O2

Lipid: Lauric Acid

Carbohydrate or Lipid?

Formula: C6H10O5

Carb: Starch

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 ACIDSA long chain of AA’s = a polypeptide…

why?Peptide bonds connect AA’s

Proteins are just folded polypeptidesProteins are made of…

AMINO ACIDS!

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: ATCGRNA: AUCG

Nucleic Acids

Elements: CHONPCarbon, Hydrogen, Oxygen, Nitrogen,

PHOSPHORUS

H:O ratio: N/A

Nucleic Acids

Monomer: NucleotideNucleotide = phosphate group, nitrogen base,

5-carbon sugarPhosphate group : P Nitrogen base: N

A, T, C, G, U (RNA only)5 Carbon sugar: CHO

Sugar is a carb… CHO Deoxyribose or ribose

Nucleic Acids

Function: HeredityStores ALL genetic informationCodes for proteins responsible for

expressed traits

Carb, Lipid, Protein, or Nucleic Acid?

Provides rigid structure for plant cellsMade of long chain of monosaccharides

Carbohydrate (cellulose)

Carb, Lipid, Protein, or Nucleic Acid?

Genes are made of thisLong, complex molecule containing

CHONP

NUCLEIC ACID (DNA)

Carb, Lipid, Protein, or Nucleic Acid?

Main component of cell membranes

LIPID (phospholipid)

Carb, Lipid, Protein, or Nucleic Acid?

Monomer: nucleotide

Nucleic Acid (tRNA)

Carb, Lipid, Protein, or Nucleic Acid?

Amino Acids are connected by peptide bonds

This macromolecule is HUGE and complex

Protein

Carb, Lipid, Protein, or Nucleic Acid?

Simple ones end in –oseComplex ones are broken down to simple

ones to power cellular respiration (and make ATP)That’s why you eat!!!

Carbohydrate

Carb, Lipid, Protein, or Nucleic Acid?

Elements: CHOH:O ratio is >2:1

LIPID

EnzymesEnzymes are

PROTEINS Biological catalysts

Speed up chemical reactions by lowering activation energy

Substrate-specific (like a lock and a key)ReusableEnds in –aseAffected by temperature and pH

Enzymes

Proteins

Enzymes

Speed up rxns (catalyze rxns) by lowering activation energy

Higher concentration of enzyme = faster reaction

Enzymes

Substrate-specific (like a lock and key)ReusableEnd in -ase

Crash Course

Biomolecules