BIOCHEMISTRY:
THE BRANCH OF CHEMISTRY
THAT RELATES DIRECTLY TO LIFE
PROCESSES
CHEMISTRY OF LIFE: CHAPTER 2
BASIC CHEMISTRY:
• Matter:
• Anything that occupies space and has mass
• Exists as solid, liquid, or gas
Examples of each state are found in the human body…
solid bones, teeth
liquid  blood
gas  air we breathe
ENERGY
 Contrasts to matter because it is massless and does not
take up space
 Can only be measured by its effects on matter
 Commonly defined as the “ability to do work” or “put
matter into motion”
 Really important inside the body and there are several
types….
FORMS OF ENERGY
WITH ANATOMY CONNECTIONS:
1.Chemical:
• Stored in bonds of chemical
substances
Anatomy Connection:
All body cavities are “run” by the
chemical energy harvested from the
foods we eat
FORMS OF ENERGY
WITH ANATOMY CONNECTIONS:
2. Electrical:
•
Results from movement of
charged particles
Anatomy Connection:
In your body, an electrical current is
generated when charged particles (ions)
move across cell membranes…
Why do “tasers” work?
FORMS OF ENERGY
WITH ANATOMY CONNECTIONS:
3. Mechanical:
• Directly involved in moving
matter
Anatomy Connection:
As the muscles in your legs shorten, they
pull on your bones, causing your limbs to
move-so you can do things like pedal a
bike, smiling, waving at someone
FORMS OF ENERGY
WITH ANATOMY CONNECTIONS:
4. Radiant:
•
Travels in waves, that is, energy of
the EM spectrum which includes Xrays, infrared, visible light, radio,
microwaves, UV light, etc…
Anatomy Connection:
Light stimulates your eyes so you can
see….UV waves give you your suntan
and stimulates production of Vitamin
D
ENERGY
CONVERSIONS
• With few exceptions, energy is
converted from one form to
another…
• In the body, chemical energy of
foods is trapped in the bonds of
a high-energy chemical called
ATP and ATP’s energy may
ultimately be transformed into
the electrical energy of a nerve
impulse or mechanical energy
of shortening muscles
ENERGY CONVERSIONS
& HEAT
 Energy Conversions are quite inefficient
 Some energy is “lost” to the environment as heat. (It is not
really lost because energy cannot be created or
destroyed, but the part given off as heat is unusable so we
call it lost)
 All energy conversions that occur in the body liberate heat
 It is this heat that makes us warm-blooded animals and
contributes to our relatively high body temperature, which
has an important influence on body functioning (the higher
the temperature, the faster chemical reactions in the body
can occur)
R.A.F.T. & GIST
EXPLAINING HOW THE TASER SHOTGUN SHELL WORKS
TASER VIDEO
R (Role of Writer): Who are you as the writer? You are a friend
trying to explain something to another friend.
A (Audience): To whom are you writing? Your troublesome friend
who was recently shot with a Taser because he ran from the cops
at a party.
F (Format): What form will the writing take? A short, easy to
comprehend letter (because your friend really doesn’t like to read
long, complicated things)
T (Topic): What’s the subject or the point of this piece? The point
is to explain to your friend how the Taser shotgun shell
works…basically, explain to your friend what happened to his body
when he was tased.
The Catch:
The letter can only be 20 words or less….giving only the GIST of
what your friend needs to know!
ELEMENTS:
 Periodic Table
 Basic substances that cannot be broken down into
simpler substances
 All living and nonliving things are composed of elements
 There are 92 naturally occurring elements (think about
this…there are only 92 and they make up everything,
living and nonliving…pretty cool)
 96% of the human body is composed of just 4 elements:
 Carbon (C) Oxygen (O) Hydrogen (H) & Nitrogen (N)
 Common Elements in the body (be sure to review) on
Page 28, Table 2.1
ATOMS
•
An atom is the smallest unit of an element
that still retains the chemical and physical
properties of an element
•
Atoms are made up of subatomic particles:
•
• Protons-positive charge
• Neutrons-no charge or neutral
• Electrons-negative charge
Protons and Neutrons make up the nucleus
or core of the atom while Electrons circulate
around the core in specific orbital paths
•
The number of protons an atom has defines
what element it is…for example, Carbon
always has 6 protons, if it had 7, it would
then be Nitrogen!
•
The number of neutrons can vary and
electrons are involved in bonding, so in a
sense, their number can vary as well.
ISOTOPES
• Isotopes are atoms of the same elements that
have different numbers of neutrons
• Why do we care in Anatomy??
• Certain isotopes called “radioactive isotopes” undergo
decay…as they decay, they emit radiation. Radiation can
be detected using a special counter or scanner.
• Radioactive isotopes are widely used in biological and
medical research….
EXAMPLES OF
RADIOACTIVE ISOTOPES IN
MEDICAL/BIOLOGICAL RESEARCH:
1. The thyroid gland uses Iodine (I). It
is possible to administer a dose of
radioactive iodine and then observe
later that the thyroid has taken it up!
2. Radiation can interfere with cell
division in larger doses.
Radioisotopes have been used in
the treatment of cancer (a disease
characterized by uncontrolled cell
division). The radiation interferes
with cancer cells multiplying.
3. In your textbook, Page 20, Third
Column: PET…also observe picture
on Page 21.
BONDING:
ATOM TO ATOM INTERACTION
 Bonding is all about the electrons…
1. Ionic: Transfer of electrons that
leaves behind charged particles
called “ions:
2. Covalent: Atoms share electrons
3. Hydrogen Bond: Occurs whenever a
H is attracted to an H in another
molecule. Very common with water.
It is a weak bond that is easily
broken
 Anatomy Connection: H-bonds help
determine 3-dimensional structure of
large molecules such as proteins and
DNA
CHEMICAL REACTIONS
 Chemical reactions involve the making or breaking of
bonds between atoms
 The total number of atoms remains the same, but the
atoms appear in new combinations
 Most chemical reactions you need to know for Anatomy
have one of the three recognizable patterns described
next…
CHEMICAL REACTION TYPES
WITH ANATOMY CONNECTIONS
 2 or more atoms or molecules combine to form a larger, more
complex molecule
 Synthesis reactions underlie all anabolic (constructive) activities that
occur in body cells. They are particularly important for growth and
repair of worn out or damaged tissues
 Synthesis reactions are necessary for bone development and hair &
nail growth.
CHEMICAL REACTION TYPES
WITH ANATOMY CONNECTIONS
 Occur when a molecule is broken down into smaller molecules,
atoms, or ions.
 Decomposition reactions underlie all catabolic (destructive) activities
that occur in body cells.
 Decomposition reactions are necessary for digestion of foods into
their building blocks for our body to use
 Also, breakdown of glycogen (a large carbohydrate molecule stored
in the liver) to release glucose when blood sugar levels start to
decline
CHEMICAL REACTION TYPES
WITH ANATOMY CONNECTIONS
 Involve synthesis and decomposition…Bonds are made and broken.
During exchange reactions, a switch is made between molecule parts and
different molecules are made.
 This type of reaction occurs in the body when ATP reacts with glucose
and transfers its end phosphate group, forming glucose-phosphate. At
the same time, the ATP becomes ADP. This important reaction, which
occurs whenever glucose enters a body cell, effectively traps the glucose
fuel molecule inside the cell for use!
INORGANIC VS. ORGANIC
o All chemicals found in the body fall into one of two major
classes of molecules: inorganic or organic
o Difference between the 2 is determined solely (with only a
few exceptions CO2 and CO) by the presence of Carbon
o Inorganic:
o Lacks Carbon! Tend to be small, simple molecules
o Organic:
o Contains Carbon! Are fairly or very large covalently
bonded molecules
o Both are important and equally essential for life!
INORGANIC COMPOUNDS:
1.
Water
 Is the single most abundant compound
in the body
 Acts as a universal solvent in which
electrolytes (salts, acids, bases) ionize
and in which chemical reactions occur
 Is the basis of transport and lubricating
fluids
 Slowly absorbs and releases heat, thus
helping to maintain homeostatic body
temperature
 Protects certain body structures (such
as the brain) by forming a watery
cushion
INORGANIC COMPOUNDS:
2.
Salts
 In ionic form are involved in nerve
transmission, muscle contraction,
blood clotting, transport of oxygen
by hemoglobin, cell permeability,
metabolism, and many other
reactions.
 Additionally, calcium salts (as bone
salts) contribute to bone hardness.
INORGANIC COMPOUNDS:
3.
Acids
 Are proton donors
 When dissolved in water, they
release Hydrogen ions
 Strong acids dissociate (break
down) completely in water &
weak acids dissociate
incompletely in water
 Example in body: Hydrochloric
acid produced in the stomach
aids in digestion
INORGANIC COMPOUNDS:
4.
Bases
 Are proton acceptors
 The most important inorganic
bases are hydroxides
 Bicarbonate ions are important
bases in the body (part of
blood).
 When bases and acids interact,
neutralization occurs-that is, a
salt and water are formed.
pH Scale: H+ Can be Measured
 The pH scale is used to indicate the
acidity and basicity (or alkalinity) of a
solution.
 It is a scale of 0-14 where 7 is neutral
and the smaller the number the more
acidic and the larger the number the
more basic the substance.
 As we move down the pH scale, each
unit has 10 times the number of H+ ions
as the previous unit.
 In living things, pH needs to be
maintained within a narrow range or
there are health consequences.
 Norma blood pH ranges from 7.35-7.45.
Slight deviations outside this range can
be fatal!
ORGANIC COMPOUNDS:
1.
Carbohydrates
 Contain carbon, hydrogen, and
oxygen
 Classified according to size as
monosaccharides, disaccharides,
or polysaccharides
 Their building blocks are
monosaccharides (these join to form
the “di” and “poly”)
 Monosaccharides include glucose,
fructose, galactose, deoxyribose, and
ribose
 Disaccharides include sucrose,
maltose, and lactose
 Polysaccharides include starch and
glycogen
 Carbohydrates are ingested as
sugars and starches
 Carbohydrates (in particular
glucose) are the major energy
sources for the formation of ATP
ORGANIC COMPOUNDS:
2.
Lipids
 Include triglycerides,
phospholipids, and
steroids (including
cholesterol)
 Triglycerides (neutral
fats) are found primarily
in adipose tissue where
they provide insulation
and reserve body fuel
 Phospholipids and
cholesterol are found in
all cell membranes.
Cholesterol also forms
the basis of certain
hormones, bile salts,
and vitamin D
ORGANIC COMPOUNDS:
3.
Proteins
 Are constructed from building
blocks called amino acids
 20 common types of amino acids are
found in the body
 Amino acid sequence determines the
proteins constructed
 Fibrous, or structural proteins are
the basic structural materials of the
body
 Globular proteins are also called
functional proteins; examples of
these include enzymes, some
hormones, and hemoglobin
 Disruption of the hydrogen bonds
of functional proteins leads to their
denaturation and inactivation
 Proteins account for over 50% of
the organic matter in the body and
have the most varied functions
ORGANIC COMPOUNDS:
4.
Nucleic
Acids
 Role is fundamental: they make
up genes, which provide the basic
blueprint of life…not only do they
determine what type of organism
you will be, but they also direct
your growth and development!
 Nucleic Acids include:
 Deoxyribonucleic Acid (DNA) which
maintains genetic heritage by replicating
itself before cell division and contains
the code-specifying protein structure
 Ribonucleic Acid (RNA) which acts in
protein synthesis to ensure that
instructions of the DNA are executed
ORGANIC COMPOUNDS:
5.
Adenosine
Triphosphate
ATP
Is the universal energy
compound used by all cells
of the body
 Without ATP, molecules cannot be
made or broken down, cells cannot
maintain their boundaries, and all life
processes grind to a halt!
 Although glucose is the most
important fuel for body cells, none of
the chemical energy contained in its
bonds can be sued directly to power
cellular work…instead, energy
released as glucose is catabolized,
captured, and stored in the bonds of
ATP molecules as small packets of
energy
TABLE TALK:
THE TERRORIST ATTACKS ON NEW
YORK CITY’S WORLD TRADE CENTER
KILLED MORE THAN 3,000 PEOPLE,
THEIR BODIES BURIED IN MILLIONS OF
TONS OF RUBBLE. IN A SITUATION LIKE
THIS, HOW CAN WE IDENTIFY
INDIVIDUALS WITH ANY CERTAINTY?