The Chemical Level of Organization

AtomsMoleculesMacromolecules• Organic v. inorganic• 4 major macromolecules• Water• Acids/bases

Macromolecules

Large Molecules

There are 4 primary types of macromolecules• Carbohydrates• Lipids• Proteins• Nucleic Acids

Carbohydrates

Composition (elemental)C, H, O’s

Twice as many H’s as O’s

Simple sugars

Complex carbohydrate

Carbohydrates Cont.Made of Elements• C, H, O (twice as many H’s as O’s or C’s)

Structure: rings or chains of carbons• Monosaccharides: a single chain or ring

e.g., glucose, fructose, galactoseInteresting note; glucose and fructose are isomers

• Dissaccharides: two monosaccharides bonded togethere.g., sucrose, maltose, lactose

• Polysaccharides: many monosaccharides bonded togethere.g., glycogen, starch

Important Characteristic• Carbs are polar and mix/dissolve well in water

-Water soluble

What are carbohydrates used for?

Major Functions:• Structural: they are building materials for

cells and tissues.

• Energy Release: the covalent bonds in carbs are broken to release energy for cells to use

• Energy Storage: carbs can be added together to store chemical energy for future use

LIPIDS

Made of Elements:• C, H, O’s (relatively few O’s)

Unsaturated fat (triglyceride)

LIPIDS

Made of Elements:• C, H, O’s (relatively few O’s)

Important Characteristic• Non-polar

-not water soluble

Types of Lipids• Triglycerides• Phospholipids• Eicosanoids (inc. prostaglandins)

• Steroids (cholesterol & hormones)

• Fat Soluble Vitamins (vitamins A, K, D, & E)

LIPID FUNCTIONS:What lipids are used for

Depending on the type of lipid:Energy Storage and Release • (e.g. triglycerides)

Insulation • (e.g., triglicerides)

Building Material/Structural • (e.g., phospholipids help make the plasma membrane of cells)

Chemical Signalers/Hormones (regulate activity)• (e.g., steroid based hormones send signals to cells that regulate/alter activity of the

receiving cell)

Fat Substitutes

Olestra; can’t be broken down

Xenical (a.k.a. Alli); a drug that blocks pancreatic lipase/enzymes so lipids are not broken down and therefore not absorbed so no caloric intake occurs…..but wear dark pants…..

What are Proteins?Made of Elements• C, H, O, + N

Structure• made of amino acids linked together• 20 different types of amino acids

--different combinations of amino acids make different kinds of proteins--200,000+ different types in humans

• amino acids are covalently bonded-peptide bond

What are Proteins?Protiens are made of chains of amino acids that fold into a specific 3D shape.

Amino acids

Proteins

Protein shape is very important to its function

Simple chains of amino acids –> primary structure

Primary structures folds to creating twists and folds due to hydrogen (and other weak) bonds secondary structure

The protein then folds again to make into a distinct 3D shapetertiary structure

some conditions can cause the protein to lose its shape—denature—and stop functioning

Primary structure

Secondary structure

Tertiary structure 3D shape related to function of protein

folding

folding

Proteins are used for/to:Major Functions

Structural: they are building materials of cells and other body material

Hormones: regulate phys and dev

Enzymes: initiate and regulate chemical reactions (rxns)

Receptors: binding sites on cells for other molecules

transport: moves things across the plasma membrane, within cells, and through blood

Movement: produces contraction/movement

Antibodies: fight infections/immune response

To a lesser extent: an energy source

EnzymesProteins that promote chemical reactions• Almost all chemical reactions in the body

“need” an enzyme to occur• Specific enzymes promote specific reactions• Allows reactions to be regulated• No enzymes no reaction

What are Nucleic Acids?

Made of Elements:• C, H, O, N, + P

Three Types• DNA• RNA• ATP

DNAFunction:

Instructions/Information on how to build and operate cells, to repair cell damage, and to make anything the cell needs to produce• When and how to make protiens• Heritable genetic material: passed from one

cell to the next (and from one generation to the next via sperm and eggs….which are cells)

DNAStructure• Made of nucleotides

-- 4 different nucleotides each with a different base molecule

• A double strand of nucleotides that are twisted like a corkscrew

• Organized into chromosomes

B

RNAStructure• A single strand of nucleotides

Many different forms of RNA

Function of mRNA• It is a copy of DNA’s protein building

instructions that is used to directly make proteins

ATP

Structure:• A molecule of adenosine + 3 phosphates

Function:• Energy from broken down carbs, lipids, and

proteins are transferred to ATP.• ATP is the direct source of chemical energy for

cell activity

ATP-ADP Cycle

ATP

ADP

Phosphate

+

Energy from broken

covalent bond

(e.g., carbs)

Phosphate

+

Usable energy for cell

ACIDS AND BASES

Acidsproduce hydrogen ions H+

• Increased H+ in solution

• Lower the pH, the more acidic

Basesproduce hydroxide ions OH-

• Increased OH- (or decreased H+) in solution

• the higher the pH, the more basic

• Alkaline=basic

Acids and Bases / pH scale

The more acidic, the lower the pH value

Refer to your lecture notes for:

Organic v. inorganicThe Properties of Water

“COMPOSITE MOLECULES”

glycolipids• sugar/carb + lipid

Glycoprotein• sugar/carb + protein

Lipoprotein• Lipid + protein