Chemistry

Matter

Anything that takes up space and has mass

Solids

Definite shape and volume

Liquids

Definite volume, shape of container

Gases

Neither a definite shape nor volume

Physical

Changes do not alter the chemical composition of a substance

Chemical

Changes alter the chemical composition of a substance, a new substance is formed

Energy

The ability to do work, does not take up space and has no mass.

Kinetic Energy

Energy to do work or create movement

Potential Energy

Stored energy that can do work due to position or condition

Electrical Energy

Nervous systems uses it from the movement of charged particles (nerve impulses) to transmit messages from one part of the body to another (electrical gradients)

Mechanical Energy

Muscle Fibers contracting causing you to move.

Radiant Energy

Eyes can detect it certain wavelengths of it (light and heat)

Chemical Energy

Stored in chemical bonds of substances like food and fossils fuels (ATP)

ADP+PI+Energy → ATP

ATP equation

Elements

Basic units of matter

Four most important elements found in the human body

Oxygen (O)

Carbon (C)

Hydrogen (H)

Nitrogen (N)

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Atoms

Building block of matter

Protons

Positively charged subatomic particles

Neutrons

Neutral or uncharged subatomic particles 

Electrons

Negatively charged subatomic particles 

Ions

Atoms that have lost or gained electrons

To identify an element we need to know the…

Atomic number

Atomic mass number

Atomic weight

Atomic number

Is equal to the number of protons that the atom contains

Mass number

Sum of protons and neutrons in an atoms nucleus

Atomic weight

Approximately equal to the mass number of the elements most abundant isotope

Isotopes

Have the same atomic number but different atomic masses due to the same number of protons but a different number of neutrons

Radioisotopes

Isotopes whose nucleus decays, giving off subatomic particles and electromagnetic energy (Think nuclear medicine)

PET (Positron Emission Tomography)

Highlights areas in the body where there is relatively high glucose use, which is characteristic of cancerous tissue.

Molecules

Two or more atoms of the SAME elements that are chemically combined (They have bonded outer electrons)

Reactants

Represented on the left side of the equation

Product

Represented by the right by the molecular formula

Compound

Two or more atoms of different elements combined chemically to form a molecule of this

Chemical Reactions

Atoms combine with or separate from other atoms

Electron Shells

Electron energy levels

Shell 1 electron maximum

2

Shell 2 electron maximum

8

Shell 3 electron maximum

18

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Atoms are most stables with this number of electrons

8 (Except shell 1 which can only hold two electrons)

Outermost orbitals

Atoms will lose, share, or gain electrons to complete this

Covalent Bond

Formed when atoms share electrons either evenly (Non-polar) or unevenly (polar)

Electrons are shared in this

Pairs

Single covalent bonds share

One pair of electrons

Double covalent bonds share 

Two pairs of electrons

Triple covalent bonds share 

Three pairs of electrons

Non-polar covalent bonds

Electrons are shared EQUALLY between the atoms of the molecule

Polar Covalent Bonds

Electrons are NOT shared equally between the atoms of the molecule

Hydrogen bonds

Weak bonds formed when the positive hydrogen atom bonds with a partially negative polar molecule

Anabolism

Forming chemical bonds (Endergonic)

Catabolism

Breaking chemical bonds (exergonic)

Synthesis Reaction. (A+B → AB)

Atoms or molecules combine to form a larger, more complex, molecule. Energy must be absorbed for chemical bond formation. These are growth inducing (anabolic) body building reactions. EX. Muscle growth and repair.

Decomposition Reaction (AB → A+B)

Smaller molecules are formed from the breakdown of larger compounds. Energy is released. Underlies all catabolic (destructive) activities in the body. EX. Digestion, fat metabolism

Single replacement reaction (AB+C → AC+B)

Involved the exchange of atoms between a compound and an element

Double replacement reaction (AB+CD → AD+CB)

Involves the exchange of atoms between compounds

A double ended arrow

Indicates reversibility

Longer arrows

Indicates the more rapid reaction in one direction over another

Reaction Rate

Can be impacted by temperature, particle concentration, catalysts, and particle size

Inorganic compounds

Do NOT contain carbon

Are usually made of small, simple, molecules. Include water, salts, and some acids and bases.

Organic compounds

Large, carbon containing covalent macromolecules. Includes carbohydrates, lipids, proteins, and nuclei acids.

Water

Most abundant inorganic compound in the body. Accounts for 2/3 of the body’s weight.

Water is vitally important for life for these four reasons

High heat capacity

Polarity/solvent properties

Chemical reactivity

Cushioning

High Heat Capacity

Water absorbs and releases a large amount of heat before it changes temperature. Prevents sudden changes in body temperature

Cushioning

Water serves a protective function. EX. Cerebrospinal fluid protects the brain from the physical trauma, and amniotic fluid protects a developing fetus.

Chemical Reactivity

Water is an important reactant in some chemical reactions. Reactions that require water are known as hydrolysis reactions. EX. Water helps digest food or break down biological molecules.

Polar molecules can…

Dissolves charged substances

Solutes

solid, liquids, or gases that are dissolved or suspended by solvents (sodium chloride)

Solvents

Liquids or gases that dissolve smaller amounts of solutes

Colloid

Forms when solutes of intermediate size from a translucent mixture (JELLO). Blood is a colloid, connective tissue

Salts

Ionic compounds that contain cations (positive ions) other than H+ and anions (negative ions) other than OH-. Easily dissociate into ions in the presence of water

Electrolytes

Ions that conduct electrical currents

Acids

Electrolytes that dissociate (ionize) in water and release hydrogen ions (H+)

Bases

Electrolytes that dissociate (ionize) in water and release hydroxyl ions (OH-)

Neutralization reaction

Type of exchange reaction in which acids and bases react to form water and a salt

pH

Measures relative concentration of hydrogen (and hydroxide) ions in body fluids. PH scale runs from 0-14, neutral is 7.

Acidic solutions

PH below 7: More H+ than OH-

Basic Solutions

PH above 7: Fewer H+ than OH-

Polymer

Chainlike macromolecules made of many similar or repeating units (monomers)

Dehydration synthesis

Monomers combine to form polymers through he removal of water molecules. Carbohydrates, fats, proteins, and nucleic acids are formed by this process.

Hydrolysis

A process in which polymers are broken down into monomers through the addition of water molecules.

Carbohydrates

Organic compounds that contain carbon, hydrogen, and oxygen. EX. Sugars and starches

Monosaccharides

Simple sugars and the structural units of the carbohydrate group (glucose, fructose)

Disaccharides

Two simple sugars joined by dehydration synthesis (sucrose, lactose, maltose)

Polysaccharides

Long-branching chains of linked simple sugars (amylose)

Lipids

Contains carbon, hydrogen, and oxygen. Insoluble in water, but soluble in other lipids (oil+water)

Saturated fats

Contain only single covalent bonds, chains are straight. Exist as solids at room temperature since molecules pack closely together.

Unsaturated Fats

Contains one or more double covalent bonds causing chains to kink. Exist as liquid oils at room temperature. Heart healthy.

Trans fat

Increases risk of heart disease

Omega3 fatty acids

Found in cold water fish and plant sources, including flax, pumpkin, and chia seeds. Appears to decrease risk of heart disease.

Phospholipids

Contain two fatty acid chains rather than three. They are hydroPHOBIC. Contains polar head that is hydroPHILIC. Form cell membranes.

Steroids

Cholesterol, bile salts, vitamin d, and some hormones

Proteins

The main building block of the body. Built from amino acid.

Peptide

Two or more amino acids

Polypeptides

Contains more than 10 amino acids.

Protein Primary Structure

Strand of amino acid “beads”

Protein Secondary Structure

Chain of amino acids twist or bend

Protein Tertiary Structure

Compact, ball-like (globular) structure.

Protein Quaternary Structure

Result of a combination of two or more polypeptide chains

Fibrous (structural) proteins

Exhibit secondary, tertiary, or even quaternary structure. Ex. Collagen and keratin.