Chapter 2: The Body’s Chemical
Makeup
Mrs. Fernandez
Anatomy & Physiology Honors
Case Study Investigation
You have a friend who is preparing for a charity marathon, but he
feels that he is too out of shape to compete with seasoned runners.
You go with him to shop for energy drinks that would give him a
competitive edge. He finally finds a drink called “Endurance” that
promises to boost an athlete's energy during strenuous
competition.Your friend drinks several bottles of “Endurance”
before the race.Your friend collapses after 2 hours of running,
only 10 miles into the 26-mile race. The medical team on the
scene discovers that your friend is dizzy, vomiting, and breathing
rapidly. In addition, his muscles are quickly alternating between
very tense and overly relaxed. An on-the-spot examination shows
that his heartbeat is rapid, yet his blood pressure is low.
Determine the possible body chemistry problems causing this set of
conditions.
Introduction to Chemistry
 Studying the human body requires knowledge of the
chemistry of the body’s structure and function.
-What are the properties? Interactions?
 Our body is composed of 2 substances: energy and matter.
What’s the difference?
 Much of our energy is released as heat
-Homeostasis
 Most important chemistry to study our body is organic
chemistry: compounds that contain carbon.
Atoms & Molecules
 All matter is composed of atoms – smallest undividable unit
-Different types of atoms called elements
 Contains 3 subatomic particles - ???
 Organized into a periodic table according to chemical
properties – developed by Mendeleev.
 Interactive table: www.ptable.com
Atom Structure & Function
 Composed of protons
and neutrons in the
nucleus, and electron
orbital’s
 Atomic mass = P + N
 Atomic # = P
 Physical Properties:
Boiling point, color,
density, hardness, melting
point, etc.
Atom Structure & Function
 For most elements, the # of N = # of P. When it differs, the
element is called an isotope.
-Makes the atomic mass different for same element
-Have very similar chemical and physical properties, but
greatly differ in nuclear properties.
-Radioactive isotopes can cause cancer, and also
cure it (radiation therapy). Also used in carbon dating
(lets us know how long something has been dead for).
Atom Structure & Function
 Gaining or losing electrons = Ions.
-Important for every day body reactions: Na/K pump,
nerve impulses, and muscle reactions
 Discovery Education: Properties of Atoms
Properties of Molecules
 Molecules are true building blocks of our body
-Made up of two or more atoms joined by chemical
bonds
-Used to replace worn down molecules or get energy
 Pure molecules: 2 or more of the same element
-Ex: Oxygen molecule made of 2 O bonded
 Compounds: 2 or more different elements
-Ex: Water, H20
Types of Bonds
 Ionic: Donating / Receiving
electrons between 2 elements
-Usually from first two
columns (readily lose an
electron) and next-to-last
column (readily gain electron)
- Form strong and rigid bonds
= crystalline structure
-Ex: Na+Cl- (table salt),
Bone matrix (calcium
chloride), and nerve
impulses
-Weaken in water (dissolve)
Types of Bonds
 Covalent Bonds: Sharing of electrons
between 2 elements
-More characteristic of the
biochemical's that make up the
human body
-Usually only involve C, H, N, O,
P&S
-Very important in carbon
compounds
-Don’t weaken in water
-Ex: hair, skin, rubber, plastic
-Breaking down covalent bonds
creates energy: metabolism
Types of Bonds
 Hydrogen Bonds: Generally temporary and weak
-Partial positive H is attracted to negative O, N, F
-Ex: Water!
-Gives the glue-like property of adhesiveness (using
moisture to stick a cup to a surface) and cohesiveness (water
attaching to itself)
-Responsible for more of the chemical reactions in our
body
Gizmo: Element Builder
Independent Assignment
Work SILENTLY 
 On page 40 answer the CONCEPT CHECK 1-3 Q+A
 Outline from pg. 40-42 starting at Parts of a Molecule.
 At least 2 sentences per paragraph as well as all terms and
definitions
Biochemicals
 Biochemicals: Organic molecules produced by chemical
reactions in living organisms
 Obtained by eating plants, or animals that have eaten plants.
 2 major categories:
1. Bioactive
2. Structural
Bioactive Molecules
 Carry out / promote
reactions in the body
 Ex: Caffeine
Structural Molecules
 Components of the body
 Ex: Tendons, Nails, Fat
 Some biochemical have both
bioactive & structural
properties, such as sugar
Biochemical Components
 Made up of Carbon skeleton and Functional group
 Carbon Skeleton: carbon atoms held by covalent bonds (can
be straight chain, branch, ring, etc)
 Functional Group: one or more elements responsible for
chemical activities
Functional Groups
 Hydroxyl (Alcohol): Made of O ; Helps other molecules





dissolve in water.
Carbonyl: Transfer electrons and help in bonding
Carboxyl: Acid, exchanges hydrogen ions with other atoms
Amino: Made of N ; Make up proteins and parts of DNA
Phosphate: Made of P, captures and releases energy in body
processes
Sulfhydryl: Made of S ; Gives unique shapes to molecules
when bonded
Isomers
 Same molecular formula, but different structural formula
(bonding and arrangement of atoms)
 May have different physical and chemical properties
 Ex: Propanol can be 1-propanol (perfumes) or 2-propanol
(rubbing alcohol)
Chirality
 The mirror image of itself
 Described as “left handed” or “right handed”, the way your
hands are mirror images of each other
 Ex: Right-handed glucose (sugar) and Left-handed glucose
(poison)
Independent Assignment
 Complete the Concept Check on page 42
 Questions and Answers
 On a separate sheet of paper
 Due Today
 Please work SILENTLY 
Acids & Bases
 pH: How many hydrogen ions are in the water
 Bases / Alkaline solutions: low concentration of H
 Bland taste, slimy feel
 Acids / Acidic solutions: high concentration of H
 Sharp taste, like lemons and vinegar
Acids & Bases
 Buffers help to neutralize acids and bases to pH of 7
 Very important in blood and body fluids
CSI Re-Visit
 Knowing a little more
about elements and their
role in the body now, is
there any new idea you
have about our CSI
patient? Could an acidic
or basic reaction be
happening his blood?
Human Molecules
 4 major organic chemical groups:
 Lipids
 Carbohydrates
 Peptides
 Nucleic Acids