Atoms, Ions, and Molecules

Has mass and occupies space

Matter

The smallest particle exhibiting chemical properties of an element

Atom

Mass of one amu and no charge

Neutron

Mass of 1 amu and positive charge of 1

Protons

1/1800th the mass of a proton or neutron, negative charge of 1, located at varying distance from the nucleus in regions called orbitals

Electrons

A substance that can’t be broken down into a simpler substance

Element

Number of protons

Atomic Number

Mass of both protons and neutrons

Average atomic mass

Top 4 elements

Oxygen, Carbon, Hydrogen, Nitrogen

Same number of protons and electrons; different number of neutrons Identical chemical characteristics; different atomic masses

Isotopes

Weighted average of atomic mass for all isotopes

Average atomic mass

Contain excess neutrons, making them unstable

Radioisotopes

Medical use of Radioisotopes

Medical use as tracers

The time for 50% of radioisotopes to become stable in the environment

Isotopes physical half-life

The time required for half of the radioactive material from a test to be eliminated from the body

Biological half-life

Why Iodine?

The thyroid naturally absorbs iodine to produce thyroid hormones

Atoms are most stable when their outer electron shell contains 8 electrons. Only care about the outermost shell.

Octet Rule

A atom or group of atoms that has electrical charge

Ions

Atoms with a positive charge

Cations

Atoms with a negative charge

Anions

Positive use of K+

Replace K+ lost in sweat

Negative use of K+

Used for lethal injection in a large dose

Groups 1 and 2 elements…

Lose electrons and become cations

Groups 6 and 7…

Typically gain electrons and from anions

Cations and anions bound by electrostatic forces

Ionic Bond

Electrons are shared between atoms

Covalent Bond

NaCl

Example of ionic compound

H2O, O2, N2, CO2

Examples of Covalent bonds

A molecule that contains different elements

Molecular compound

A chemical property that describes the tendency of an atom or a functional group to attract electrons toward itself

Electronegativity

Unequal sharing of electrons

Polar Covalent Bond

Equal sharing of electrons

Non-polar covalent bonds

Forms between polar molecules, individually weak, collectively strong, influences how water molecules behave

Hydrogen Bonds

A+B= AB

Synthesis reaction example

Atoms or molecules combine to form a larger, more complex molecule

Synthesis Reaction

AB= A + B

Decomposition Reaction Examples

Molecule is broken down into smaller molecules

Decomposition reaction

AB + C= AC + B

Exchange Reaction Example

Involves simultaneous synthesis and decomposition reactions as bonds are both made and broken

Exchange Reactions

2/3 of human body by weight, can form four hydrogen bonds with adjacent molecules, oxygen is more electronegative because its nucleus pulls more strongly on shared electrons

Molecular Structure of water

Can absorb and release large amounts of heat before changing temperature itself

High heat temperature

Water evaporation requires large amount of ear absorption to break down hydrogen bonds

High heat vaporization

Attraction between water molecules

Cohesion

Attraction between water molecules and other surfaces

Adhesion

Polarity allows nutrients, ions, and waste products to dissolve and be transported throughout the body

Polar solvent properties

Water-loving

Hydrophilic

Water hating

Hydrophobic

How do nutrients and electrolytes travel through body

Polar so they dissolve in water

Require carrier proteins (fats and cholesterol, hormones)

Hydrophobic substances

Have polar and non-polar regions (Phospholipids)

Amphipathic molecules

No chemical changes and substances can be separated

Mixtures

Types of mixtures

Solutions, Colloids, and Suspension

____ contains all three categories of water mixtures

Blood

Homogenous

Solutions

Jelly, Gelatin

Colloids

Big particles that will settle if mixing is stopped

Suspensions

How acidic or basic a solution is based on concentration of H+

PH

PH

-log10[H+]

Water is

Neutral

Saliva pH

6.5-7.5

Blood pH

7.35-7.45

Stomach pH

1.5-6.5

Large intestine pH

4.7-7

Small Intestine pH

4-7

More H+

Acidic

Less H+

More alkaline/basic

How to denature a protein

Extreme changes in temperature and pH

Denaturation changes

Shape and function

A chemical solution that helps resist sudden changes in pH

Buffer

If pH drops

Buffers bind H+

If pH rises

Buffers release H+

General characteristics of macromolecules

Always contain carbon, hydrogen, and oxygen. May have nitrogen, phosphorus, or sulfur.

Molecules are made up of

Repeating monomers

Breaks larger molecules by adding water

Hydrolysis

Builds larger molecules by removing water

Dehydration Synthesis

Diverse group of fatty, water-insoluble molecules

Lipids

Energy storage, cellular membrane components, and hormones

Lipid functions

Phospholipids, Triglycerides, and Steroids

Classes of lipids

Used for long-term energy storage

Triglycerides

triglyceride makeup

One glycerol backbone and three fatty acids

No double bonds, straighter chains

Saturated fatty acids

One or more double bonds, bent chains

Unsaturated fatty acids

Cholesterol helps

Maintain shape/structure and serves as a precursor to hormones

“Bad cholesterol”, delivers cholesterol to tissues

LDL

“Good cholesterol” , helps remove cholesterol from tissues

HDL

Contain carbon, hydrogen, and oxygen

Carbohydrates

Carbohydrate functions

Quick energy, structural support, energy production

Single sugar unit

Monosaccharide

Monosaccharide examples

Glucose, fructose, galactose

Contain two monosaccharides joined together

Disaccharide

Disaccharide examples

Sucrose, Lactose, Maltose

Long chain of monosaccharides

Polysaccharide

Polysaccharide examples

Starch, Glycogen, Cellulose

When blood glucose drops the liver can

Break down glycogen and release glucose into the blood

A proteins function depends on its

Shape

Polymers of amino acids

Proteins

Amino acids are joined by

Peptide bonds

Protein structure examples

Collagen, keratin

Protein Movement Examples

Actin and Myosin

Protein Transport examples

Hemoglobin