Download BIOCHEMISTRY: THE CHEMICAL COMPOSITION OF LIVING

BIOCHEMISTRY: THE CHEMICAL
COMPOSITION OF LIVING MATTER
By: Josh Johnson
CONCEPTS OF MATTER AND ENERGY
• Matter: What the universe is made out of
• Can be seen, smelled, and touched.
• Exists in the three physical states
• It can be changed physically and chemically
ENERGY
• Energy: Doesn’t take up space and contains no mass
• Measured only by effects on matter
• Kinetic: Energy that does work
• Potential: Energy that is stored
CHEMICAL ENERGY
• Chemical Energy is stored into the bonds of chemical
substances
• Once bonds are broken, the potential energy becomes
kinetic energy
• Foods give the chemical energy we need in order for
our bodies to work
ELECTRICAL ENERGY
• The movement of charged particles
• An electrical current in your body happens when these
charged particles called ions, move across your cell
membranes
MECHANICAL ENERGY
• Involved in moving matter
• Whenever we lift or move something with our bodies,
its because of the mechanical energy
RADIANT ENERGY
• Moves through the energy of the electromagnetic
spectrum
⁻ X rays and infrared, visible light, radio, and
ultraviolet waves
• Ultraviolet waves gives our bodies access to make
vitamin D
ENERGY FORM CONVERSIONS
• The bonds that the chemical energy of food is stored
into ATP ( adenosine triphosphate)
- can be transferred mechanically or electrically by
shortening muscles
• Energy conversions are somewhat weak due to the
loss of energy to the environment as heat
• When matter is heated, its particles begin to move
quicker, which increased the kinetic energy
ELEMENTS AND ATOMS
• Matter is composed of many different elements
• Elements- unique substances that cannot be broken
down into simpler substances by ordinary chemical
methods
• 112 elements are known for certain
• 92 occur naturally
• 113-116 on the periodic table are theoretical
• Oxygen, nitrogen, hydrogen, and carbon make up 96
percent of the body
COMPOSITION OF MATTER
Migyn Kim
ELEMENTS AND ATOMS
•
Elements – unique substances that cannot be broken down into simpler substances by
ordinary chemical methods
• 4 elements –– carbon, oxygen, hydrogen, and nitrogen –– make up 96% of body weight
•
Periodic table – complete list of elements
•
Atom – smallest part of an element that still retains its special properties
•
Atomic symbol – a one- or two-letter symbol indicating a particular element
ATOMIC STRUCTURE
•
Atoms can be split into smaller particles
•
Protons – have positive charge
•
Neutrons – uncharged or neutral
•
Protons and neutrons have approximately same mass (1 amu)
•
Electrons – negative charged equal in strength to positive charge of protons but have smaller
mass (0 amu)
•
Particles with same charge repel each other
•
Particles with unlike charges attract each other
•
Neutral particles neither attract nor repel by charged particles
•
For any atom, the number of protons and electrons is always equal
PLANETARY AND ORBITAL MODELS
•
Planetary model – portrays the atom as a miniature solar system in which the protons and
neutrons are clustered at the center of the atom in the atomic nucleus
• Orbitals – regions around the nucleus in which a given electron or electron pair is likely
to be found most of the time
•
Orbital model – more modern model of atomic structure which has proved to be more useful
in predicting the chemical behavior of atoms
• It depicts the general location of electrons outside the nucleus as a haze of negative
charge referred to as the electron cloud
•
Most of the volume of an atom is empty space
•
Nearly all of the mass of an atom is concentrated in the central nucleus
IDENTIFYING ELEMENTS
•
Atoms of different elements are composed of different numbers of protons, neutrons, and
electrons
•
Atomic number – number of protons in an atom
• Atomic number indirectly also tells us the number of electrons
•
Atomic mass number – sum of the protons and neutrons contained in its nucleus
ATOMIC WEIGHT AND ISOTOPES
•
Atomic weight – average of the mass numbers of all of the isotopes of an element
•
Isotopes – different atomic form of the same element; vary only in the number of neutrons they
contain
•
Isotopes have the same atomic number but different atomic masses
•
B/c all of an element’s isotopes have the same number of electrons, their chemical properties
are exactly the same
•
Atomic weight of any element is approximately equal to the mass number of its most abundant
isotope
•
Radioisotopes – heavier atoms that are unstable and tend to decompose to become more stable
•
•
Radioisotopes are used in minute amounts as valuable tools for medical diagnosis and
treatment
Radioactivity – the process of spontaneous decay seen in some of the heavier isotopes, during
which particles or energy are emitted from the atomic nucleus; results in the atom becoming more
stable
•
Radioactive decay are damaging to living cells
MOLECULES AND COMPOUNDS
•
2 or more atoms=Molecules
•
H(Atom)+H(Atom)=H2(Molecule)
•
2 or more different atoms=Compound
•
4H+C=CH4(Methane)
•
Molecule of methane=compound
•
Molecule of hydrogen does not =compound
•
Compounds are different from atoms
MOLECULES AND COMPOUNDS
•
Atom= smallest particle of element
•
Molecule= smallest particle of compound
•
Breaking bonds between atoms of a compound
CHEMICAL BONDS AND CHEMICAL
REACTIONS
By Ashley Barranco and Kaleb Libby
CHEMICAL BONDS
BOND FORMATION
•
A chemical bond is an energy relationship that involves interactions between the
electrons of the reacting atoms.
ROLE OF ELECTRONS
•
Electrons occupy generally fixed spaces around the nucleus called Electron shells or
energy levels.
•
There are 3 main shells in an atom. The inner, the middle, and the outer shell. The
inner can hold up to 2 electrons, the middle can hold up to 8, and the outer can hold
up to 18.
VALENCE SHELLS
•
The most important shell is the valence shell, for when it is full, the atom is completely stable,
but if it is lacking, then it is scrambling around trying to get to a stable state but giving
receiving or sharing electrons with other atoms.
•
This is how chemical bonds are formed.
TYPES OF CHEMICAL BONDS
•
Ionic Bonds: form when electron are completely transferred from one atom to another
•
Ions: when atoms gain or lose electrons, their charges are no longer balanced
•
Anions: Negatively charged ions
•
Cation: Positively charged ions ( NaCl )
•
Covalent bonds: molecule in which atoms share electrons are called covalent molecules and their
bonds are covalent bonds. ( CH4- Carbon has 4 electrons but needs 8, so Hydrogen shares 4 of its
electrons so it can become active)
•
Hydrogen Bonds: extremely weak bonds formed when a hydrogen atom bonds to 1 electron
hungry nitrogen atom or oxygen atom and the hydrogen atom forms a bridge between them.
•
If molecules have equally shared electrons then they are called non-polar covalently bonded
molecules.
CHEMICAL REACTIONS
WHAT IS A CHEMICAL REACTION?
•
Chemical reactions occur whenever atoms combine with or dissociate from other atoms.
When atoms unite chemically, chemical bonds are formed.
•
Chemical reactions involve the making or breaking of bonds between atoms.
• The number of atoms remain the same, but they appear in new combinations.
TYPES OF CHEMICAL REACTIONS
•
Synthesis Reactions
•
Decomposition Reactions
•
Exchange Reactions
SYNTHESIS REACTIONS
•
Synthesis reactions occur when two or more atoms or molecules combine to form a larger,
more complex molecule. This is represented by
A + B  AB
• Always involve bond formations
• Are energy absorbing functions
• Underlie all anabolic activities that occur in body cells
• Particularly important for growth and for repair of worn-out or damaged tissiues
DECOMPOSITION REACTIONS
•
Decomposition reactions occur when a molecule is broken down into smaller molecules,
atoms, or ions. Represented by:
AB  A + B
• Synthesis reactions in reverse
• Bonds are always broken, and the products are smaller simpler than the original
molecules.
• Chemical energy is released as bonds are broken
• Underlie all catabolic processes that occur in body cells. They are molecule-degrading
reactions
• An example of a decomposition reaction is the digestion of food
EXCHANGE REACTIONS
•
Exchange reactions involve both synthesis and decomposition reactions: bonds are both
made and broken
• During exchange reactions, a switch is made between molecule parts and different
molecules are made. Represented by:
AB + C  AC + B
AB + CD  AD + CB
ORGANIC COMPOUNDS
Carbon containing compounds.
Examples: carbohydrates, lipids,
proteins, nucleic acids, and ATP
CARBOHYDRATES
• Contain carbon, hydrogen,
and oxygen.
• Example: sugars and starches
• Classified by size as
monosaccharides,
disaccharides, and
polysaccharides.
MONOSACCHARIDES,
DISACCHARIDES, AND
POLYSACCHARIDES
•
•
Monosaccharides are the
“simple sugars”. They are
singular in structure.
Example: glucose.
Disaccharides are “double
sugars”. They are formed
when 2 monos are joined by a
synthesis reaction.
•
An example is lactose,
which is found in milk.
•
Polysaccharides are the
“many sugars”. They are long
chains of linked monos. An
example is starch.
LIPID
S
• Large group of organic
compounds.
• The most common lipids in the
body are triglycerides,
phospholipids, and steroids
TRIGLYCERIDES, PHOSPHOLIPIDS,
AND STEROIDS
•
•
Triglycerides are known as
the “neutral fats”. Their
function is to help keep the
body warm and protect body
tissues
•
Phospholipids are very similar
to triglycerides. However, the
“head” of a phospholipid has
an electric charge.
Steroids are flat molecules
formed by 4 interlocking
rings. The most important
steroid is cholesterol, which
is found in meat, eggs, and
cheese.
PROTEIN
S
• Make up over 50% of the
organic matter in the body
• Play vital roles in cell function
• Can be classified as either
fibrous or globular.
FIBROUS (STRUCTURAL) AND
GLOBULAR (FUNCTIONAL)
PROTEINS
• Fibrous appear
most often in
body structures.
They provide
strength in body
tissues. An
example is
collagen.
• Globular are
mobile molecules
that play large
roles in most
biological
processes.
Examples are
antibodies,
hormones, and
enzymes.
NUCLEIC ACIDS
• Make up the genes
• Direct an organism’s growth and
development.
• Are made up of nucleotides. Each
nucleotide consists of 3 parts
(nitrogen containing base, pentose
sugar, and a phosphate group).
• The 2 major kinds of nucleic acids
are deoxyribonucleic and
ribonucleic
DNA AND RNA
• DNA is the
genetic material
found in a cell’s
nucleus.
• DNA is a long
double chain of
nucleotides.
• RNA carries out
the orders for
protein synthesis
issued by DNA.
• RNA molecules
are single
nucleotide
strands.
ADENOSINE TRIPHOSPHATE
(ATP)
• Provides a form of chemical energy
that is usable by all body cells.
• ATP is structured like a modified
nucleotide. It has an adenine base,
ribose sugar, and 3 phosphate
groups.
• ATP is basically used to provide
cellular energy.
INORGANIC COMPOUNDS
Non-carbon containing molecules that tend to be small and simple.
WATER
Water has many properties that make it important including:
1. High heat capacity
2. Polarity/Solvent properties
3. Chemical reactivity
4.Cushioning
SALTS
•
Commonly found in the body, most plentiful being :
1. Calcium
2. Phosphorus
Both being found mainly in teeth and bones
Electrolytes
Substances that conduct an electrical current in
solution
ELECTROLYTES
•
Substances that conduct an electrical current in solution
ACIDS & BASES
•
Acids- Have a sour taste and can dissolve many metals
•
Bases- Have a bitter taste, and feel slippery
•
Acids and bases are electrolytes, they ionize and then dissociate in water
and then conduct an electrical current
•
The higher the pH, the more of a base it is