:
:

Kinetic energy : energy of motion
Potential energy : stored (inactive) energy
Electrical energy : movement of charged particles
Chemical energy : energy of bonds (stored within molecules)
Mechanical energy : energy used to move
Radiant energy : electromagnetic energy (x-rays, heat, light)

All matter is composed of elements .
Each element is composed of the same atoms .
Atoms have:
 Protons (p + ) : positive charge
 Neutrons (n) : neutral
 Electrons (e ) : negative charge
The most abundant elements in the human body are (in order): Oxygen (O), Carbon (C), Hydrogen (H), and
Nitrogen (N)

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:

C O V A L E N T B O N D S
Electrons are shared
(either equally or not equally)
Ex: H
2
, O
2 or C
(glucose)
6
H
12
O
6
I O N I C B O N D S
Electrons are transferred between atoms (one atom gives e , the other receives e )
Ex: salts like NaCl
(sodium chloride)

http://www.accessexcellence.org/RC/VL/GG/ecb/ecb_images/02_06_stable_arrangement.jpg

Hydrogen bonds : a bond between a hydrogen of one compound to a nitrogen or oxygen of another compound.
TWO different compounds are involved!
Ex: 2 water molecules http://www.google.com/imgres ?

S Y N T H E S I S :
Anabolic ; to make or create; to build up; these reactions make chemical bonds
Require energy
A + B  AB
D E C O M P O S I T I O N :
Catabolic ; to break down or decompose; these reactions break chemical bonds.
Release energy
AB  A + B

E X C H A N G E :
Both synthesis & decomposition; parts of 2 compounds switch
(exchange) places.
R E V E R S I B L E :
Reactions that can go in both directions.
A + B ↔ AB
AB + CD  AC + BD

I N O R G A N I C :
 Molecules that lack
C (except CO and
CO
2
)
O R G A N I C :
 Molecules that contain C (& usually
H & O)
 Include: salts, water,
CO
2
, and many acids
& bases
 Include: carbohydrates, lipids, proteins, & nucleic acids

Water : most abundant inorganic compound in the body.
Important b/c
• Maintains body temperature (has high heat capacity )
• Dissolves many substances ( solvent of life )
• Most chemical reactions occur in water (chemical reactivity)
• Water protects and cushions (CSF, fetus)
Salts : ionic compounds ; are electrolytes . Important b/c
• Transport substances in and out of cell
• Conduct nerve & muscle impulses

When electrolytes release more H+ (ions) than OH- (ions), the resulting solution is an acid while more OH- than H+, it is a base .
Acidity is measured based on the concentration ([ ]) of H+ and OH-.
These are inversely proportionate: increased
[H+]=decreased [OH-].
The measurement is a scale called the pH scale . It ranges from 0-14 , with 7 being neutral (water). The scale:
Acids= high [H+] , low [OH-], 0-6= acidic Ex: HCl
Bases= low [H+], high [OH-], 8-14=basic or alkaline Ex: NaOH
Neutral= [H+]=[OH-], 7, water
Buffers: maintain the stability of acids-bases within the body. by taking up excess H+ or OH-.

http://www.google.com/imgres ?

http://www.google.com/imgres ?
http://www.google.com/imgres ?
http://sps.k12.ar.us/massengale/images/cell20me mbrane.jpg
http://www.valueflora.com/cc p51/media/images/product_c ategory/fruit_superior.jpg

• Contain C, H, & O in a fixed ratio (2 H for every 1 C and 1 O).
• Known as sugars
• Three categories:
Monosaccharides are simple sugars (1 sugar: glucose
(C
6
H
12
O
6
) a.k.a. blood sugar , fructose & galactose
Disaccharides are double sugars: sucrose (table sugar), lactose (milk sugar) & maltose (malt sugar)
Polysaccharides are many sugars: starch and glycogen

• Contain C, H, & O but not in a fixed ratio.
• Do NOT dissolve in H
2 chloroform
O; but dissolve ( soluble ) in ether and
Fats ( most common lipids) store energy (supply more than carbs gram for gram); ex: triglyceride (3 fatty acids & 1 glycerol)
 can be saturated or unsaturated
Phospholipids are major constituent of cell membranes; contain 2 parts: hydrophilic (meaning water loving or H
2
O soluble) and hydrophobic (meaning water fearing or insoluble in H
2
O).
Steroids: simplest & most important is cholesterol (found in all body cells and used to synthesize hormones & other steroids) .

• Composed of amino acids ; contain C, H,
O, N & sometimes S
• Provide structural materials, energy sources, hormones,
& enzymes in which their structure determines their fcn .
• Most have a 3D shape that can be denatured , or destroyed , easily by high temperatures, pH, radiation, or electricity .
Glycoproteins are proteins w/ carbs, on cells, act as receptors for chemical messages
& recognition .
Antibodies protect against foreign bodies (invaders).
Enzymes are catalysts in chemical rxns but are not part of the rxns ( not consumed ).

http://www.google.com/imgres ?
http://www.google.com/imgres ?

• large and complex molecules that contain C, H, N, O and P
• Composed of nucleotides ( building blocks ).
• Nucleotides contain: a 5-C sugar (called a pentose ), a phosphate group, and a nitrogenous base (adenine, cytosine, guanine, thymine, or uracil)
2 groups:
1. RNA (ribonucleic acid) : sugar is a ribose; single stranded molecule
2. DNA (deoxyribonucleic acid) : sugar is a ribose without an O; double stranded molecule; molecular code of life

http://www.scq.ubc.ca/wp-content/dna.gif

This slide show was developed by Dana Halloran,
Cardinal Mooney High School, Sarasota, FL.
Used with her personal permission, adapted and amended by Rosa Whiting,
Manatee School for the Arts, Palmetto, FL.