By: Josh Johnson

BIOCHEMISTRY: THE CHEMICAL COMPOSITION OF LIVING MATTER

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

• 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

MOLECULES AND COMPOUNDS

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.

LIPIDS

• 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.

PROTEINS

• 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

Substances that conduct an electrical current in solution

Electrolytes

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