basic unit of life extremely small made up of the subatomic particles 1. Protons 2. Neutrons 3....

basic unit of life extremely small made up of the subatomic particles1. Protons2. Neutrons3. Electrons

* # of protons(+) & electrons(-) are the same therefore atoms are neutral

positively charged particles (+)

located in the nucleus

about same mass as neutrons

bound to neutrons to form nucleus

neutral (no) charge

located with protons in nucleus

bound by strong forces w/protons to form nucleus

negatively charged particles (-)

very light in constant

motion in space surrounding nucleus, the orbitals

at the center of atom

Made up of protons & neutrons

positively(+) charged

1. List the 3 atomic particles that make up atoms.

2. What is the charge of a proton?3. What is the charge of a neutron?4. What is the charge of an electron?5. Which particles make up the nucleus?

…a pure substance consisting of ONLY one type of atom

represented by 1 or 2 letter symbols examples> C = carbon, Na = sodium

NOVA ELEMENTS: Element Hunt

Check out Carbon (C)

ATOMIC NUMBER

= # of protons = # of electrons

ATOMIC WEIGHT(mass number)= # of protons + number neutrons

Lets build a few elements…

Atoms of an element can have a diff. # of neutrons.

>these are called isotopes.• Isotopes are identified by their mass

number.• b/c they have same # of electrons, ALL

isotopes of an element have same chem. properties.

Some isotopes are radioactive…sounds scary…

they are very unstable constantly break down

over time give off radiation=bad can be used to treat

cancer & kill bacteria

A combination of 2 or more elements held together by chemical bonds.

Compounds are written in shorthand

H2O

Properties of cmpds are diff. from the elements they are formed from.

*Bonds form using the electrons surrounding the nucleus.*Electrons available to form bonds are called valence

electrons.

2 TYPES OF CHEM. BONDS1. Ionic bonds>when 1 or more electrons are transferred from 1 atom to

another>atoms are neutral, when they lose electrons they become

positive (LEO the lion goes GER)>positively & negatively charged atoms are called ions

2. Covalent bonds>when electrons are shared between atoms; the moving

electrons travel in orbitals of both atoms; single, double, triple bonds

Molecules are the smallest unit of most cmpds.

These are the intermolecular forces, or slight attractions that devel. betw. oppositely charged regions of molecules.

NOT as strong as chemical bonds, but can still hold molecules together.

May the force be with you!

1. How do you determine the atomic number?

2. How do you determine the atomic weight?3. Explain the difference between ionic and

covalent bonds.

When life on Earth began 4 billion years ago, water provided a medium in which all other molecules could interact.

Approx. 75% of Earth’s surface is covered in water, & life would cease w/o it.

About 2/3 of all the molecules in your body are H2O molecules!

only substance naturally found in all 3 physical states (what are the 3 physical states?)

less dense in its solid form than in its liquid form

has a high specific heat index clings to itself and other molecules is the universal solvent.

polar molecules

molecules in which the charges are unevenly distributed.

Example: Look at the water molecule to the right.

O-

H+H+

Water clings to itself (cohesion) and to other substances (adhesion) very readily.

The strong attraction betw. water molecules causes high surface tension of water.

Cohesion and adhesion are what cause capillary action – the upward movement of water(roots work this way)

A mixture is a material composed of 2 or more elements or cmpds that are physically mixed together, but not chemically joined.

SOLUTIONS All cmpds are evenly

distributed throughout the solution.

SUSPENSIONS Mixture of water

and non-dissolved materials.

Solvent> the substance in which the solute dissolves (water)

Solute> the substance that is dissolved in a solvent (sugar, salt)

Pure water is naturally a neutral compound (pH 7).

An acid is any cmpd that releases hydrogen ions(H+) when dissolved in water.

A base is any cmpd that takes hydrogen ions ions(H+) from water.

pH scale is a measurement syst. Which indicates the concentration of H+ ions in solution.

The pH scale is a way of relating the amount of hydrogen ions from one solution to another.

Bases have lower hydrogen ion concentrations than that of water (pH>7).

Acids have a higher concentration of hydrogen ions than that of water (pH<7).

H+

OH-

pH of fluid in most cells in humans usually at 6.5 - 7.5

If the pH changes it affects chem. RxNs within our cells.

> pH is important for maintaining homeostasis.

>body uses dissolved cmpds called buffers, which are weak acids or bases that react w/strong acids or bases to prevent rapid changes in pH.

1. What do larger numbers on the pH scale represent?

2. What do smaller numbers on the pH scale represent?

3. What is a pH of 7 considered?4. Give an example of a substance with a pH

of 7.

macro=large large molecules made from 1000’s of smaller molecules Monomers (single molecules) join together

to form polymers (many)4 organic CMPDs found in living things:1. carbohydrates 2. proteins3. lipids 4. nucleic acids

cmpds made of C, H, and O main source of energy simplest form of carb is sugar called a

monosaccharide - glucose & fructose - break down of these sugars forms instant energy for cell activities

Larger sugars are called polysaccharides(many sugars)

Glycogen & Cellulose

Made of mostly C and H Examples: fats, oils, waxes used to store energy important for membranes & H2Oproofing Do NOT dissolve in H2O - WHY?2 Types:1. Saturated - solid at room temperature, single

bonds between carbon atoms2. Unsaturated - liquid at room temperature, double

bonds between carbon atoms

LIPIDS

Provide struct. for tissues & carry out cell metabolism.

Basic building blocks of proteins are amino acids.

Help control rate of RxNs and cell process, form bone & muscles, transport materials, help fight diseases

Long chains made of nucleotides. Store & transmit hereditary or genetic

info 2 Kinds

1. DNA - deoxyribonucleic acid2. RNA - ribonucleic acid

Made up of three components:1. Sugar2. Base (A, C, T, G)3. Phosphate group

Fold your paper so that there are six boxes! Cut the pages out. Fold it so it is a book. On cover write “MACROMOLECULES” Then set up your book so it follows this

pattern:Pictures (left side) Macromolecules (right)

Info…….

What is the difference between a physical and chemical change?

Let’s try an example to jog your memory.

Tearing a piece of paper Burning a piece of paper

Chemical or Physical Change?

WHY?

Paper has NOT been changed into a new substance - it’s still paper.

Chemical or Physical Change?

WHY?The chemical RxN causes the cellulose in the paper to react with oxygen, forming carbon dioxide and water. SO, Paper is transformed into new substances!

In a physical change . . .◦ There is a change in the state of matter only.◦ Original components remain.

In a chemical change . . .◦ A reaction occurs.◦ Original components are changed into new ones.

Substances that are combined or broken apart during a chemical reaction are called:

REACTANTS New substances that form during a

chemical reaction are called:PRODUCTS

C6H10O5 + 6O2 -----> 6CO2 + 5H2OCellulose and Oxygen react to produce Carbon Dioxide and Water

What are reactions that release energy called?

EXERGONIC( “exer” = to move out, “gonic” = energy)

What are reactions that absorb energy called?

ENDERGONIC(“endo” = to come in, “gonic” = energy)

THINK: Where does the energy come from to initiate the combustion of cellulose?

Every reaction needs a “kick in the butt” to get it started.

The energy needed to start a reaction is called the activation energy.

This energy is used to “activate” a reaction by breaking existing chemical bonds of the reactants needed to make the products.

CATALYSTS! You already know that catalysts speed up reactions – but HOW do they do it?

Catalysts lower the activation energy, in other words make it so less energy is needed to get the RxN going. Like gasoline on a flame

Without Enzyme

With Enzyme

FreeEnergy

Progress of the reaction

Reactants

Products

Free energy of activationFree energy of activation

Enzymes are large proteins that are used to trigger and control particular chemical reactions in your body.

Ex: digestion

Enzymes bind specifically to substrates, which act as reactant molecules.

Substrates bind to the active site on an enzyme.http://www.lewport.wnyric.org/jwanamaker/animations/Enzyme%20activity.html

carbohydrates,

lipids, protein

Vitamins,

minerals

ENZYMES

Temperature Concentration

pHEnzymes are pretty picky about their environment. Enzymes are pretty picky about their environment. If the temp or pH is not to their liking, their If the temp or pH is not to their liking, their function will decline, and many times they will function will decline, and many times they will stop working all together!stop working all together!