• These smaller particles are:
protons – particle with a positive charge
located in the nucleus
neutrons – particle with NO charge
located in the nucleus
electrons – particle with a negative charge
located outside the nucleus
Atom-
- smallest particle of matter that has all its chemical properties
-Atoms are made up of 3 smaller particles.
ATOMS
protons neutrons electrons
Positive
charge (+)
No
charge (0)
Negative
charge (-)
Inside
the
nucleus
Inside
the
nucleus
Outside
the
nucleus
Element • substance that is made up of only 1 type of atom.
• there are over 100 different elements
• each element has its own symbol usually 1 or 2 letters
Write down the NAME of the following elements:
Mg: ________________________
C: __________________________
Cl: _________________________
Na:__________________________
Write down the symbol for the following elements:
Lithium: ____________ Sulfur:________ Neon:_____________
Krypton:____________ Lead:_________ Gold:_____________
Here’s a picture of a Carbon Atom:
-Protons & Neutrons are bigger in size and are found in the nucleus (center) of
the atom.
-Electrons are smaller in size and are found in orbitals around the nucleus.
-Atoms have NO charge because the number of protons equals the number of
electrons
Atomic Number-
-tells you the number of protons & electrons
-this number is located above the symbol of the element
Write down the ATOMIC NUMBER of the following elements:
S:__________ Silver: __________ Pt: _________ Boron: __________
How many protons does S have? ___________ electrons? ___________
How many protons does Boron have? __________ electrons? ___________
Atomic Mass- • -tells you the number of protons PLUS neutrons
• -this number is located below the symbol of the element
• -this number usually in decimal form because not all atoms are identical; some have
extra neutrons. These atoms are called isotopes
Write down the ATOMIC MASS of the following elements:
S:__________ Silver: __________ Pt: _________ Boron: __________
To find the number of neutrons you must do the following:
Atomic Mass minus Atomic Number
Practice:
How many neutrons does Fluorine have? ___________________________
How many neutrons does Sodium have? ____________________________
HOW TO DRAW AN ATOM:
• First you must figure out how many protons, neutrons & electrons the atom has.
*Remember*
- the Atomic Number tells you the number of protons and electrons
- the Atomic Mass tells you the number of protons PLUS neutrons
- -To find the number of neutrons: atomic mass MINUS atomic number
EXAMPLE: draw an atom of Beryllium
Atomic Number = ________ Atomic Mass = _________
figure out the number of:
Protons = ___________ Electrons = ________ Neutrons = __________
YOU’RE HALF WAY THERE!!
ORBITAL RULES:
• -The 1st orbital holds 2 electrons. Once it has 2 electrons it is FULL
• -The 2nd orbital holds 8 electrons. Once it has 8 electrons it is FULL
• -The 3rd orbital holds 8 electrons. Once it has 8 electrons it is FULL
-Now that you know the number of protons, electrons, and neutrons Beryllium
has, use the orbital rules to draw the atom below:
WATER: The chemical formula for water is: H2O
- The hydrogen atoms are attached to the oxygen atom by a covalent bond
- Each water molecule is attached to each other by a hydrogen bond
-There are 2 Hydrogen atoms & 1 Oxygen atom
-What a water molecule looks like this:
PROPERTIES OF WATER:
-The ability of water to stick to other things is called adhesion
-The ability of water to stick to itself is called cohesion
-Water has a slight positive charge and a slight negative charge. This makes
water a polar molecule.
-The Oxygen atom holds on to the electrons a lot longer, so this side is slightly
negative.
-The Hydrogen atoms rarely see the electrons, so this side is slightly positive.
6 Most Important Elements in Biology:
CARBON:
-Carbon can make 4 (#) bonds, which is the most out of the 6 elements.
- It allows you to make really large/ long molecules.
- Any molecule that contains Carbon is said to be organic.
1. CARBON 2. HYDROGEN 3. OXYGEN
4. NITROGEN 5. PHOSPHORUS 6. SULFUR
**THE MOST IMPORTANT ELEMENT OF THESE IS: CARBON
Organic Molecules (Biological Molecules)
Carbohydrates: Proteins:
Lipids: Nucleic Acids:
-There are 4 (#) different types of organic molecules:
1. Carbohydrates 2. Proteins
3. Lipids 4. Nucleic Acids
1. Carbohydrates: (Sugars)
- Shape: Carbohydrates look like rings hooked
together to form a chain.
- JOB: to provide living organisms with energy
- Elements: C, H, O
-Subunit: monosaccharide - means 1 sugar
disaccharide - means 2 sugars
polysaccharide - means many sugars
Examples of Carbohydrates:
2nd type- STRUCTURAL CARBOHYDRATE- helps with shape
There are 2 major types of carbohydrates:
1 type- STORAGE CARBOHYDRATE- stores extra sugar
examples: starch is found in plant cells
glycogen is found in animal cells
examples: cellulose is found in plant cells
chitin is found in animal cells
2. Proteins:
- Examples: Proteins are found all over your body! Here are some examples:
- Keratin- found in your hair & nails
(makes them strong & shiny)
- Collagen- found in your skin (makes it smooth & wrinkle-free)
- Hemoglobin- found in your blood (carries oxygen)
- Enzymes- speed up chemical reactions
- When a protein loses its shape and can’t work anymore it’s said to be
denatured. (like if your key got ran over by a car…..it loses it’s shape and can’t work
anymore)
- JOB: many different jobs; depends on the protein
-Elements: C, H, O, N, S
-Subunit: Proteins are made out of Amino Acids
- Shape: Proteins start off as a chain, but then their final shapes vary
3. Lipids:
- JOB: to store energy; (long term energy source)
-Elements: C, H, O, P
-Subunit: made out of 1 glycerol and 3 fatty acids
-There is a special lipid called a phospholipid, which is found in the cell membrane of all cells.
-Shape: lipids with 3 fatty acids look like this:
-Shape: lipids with 2 fatty acids (phospholipids) look like this:
Examples of Lipids:
2 types of fats:
1. Saturated Fats- are BAD for you & come from ANIMALS
2. Unsaturated Fats- are GOOD for you & come from PLANTS
4. Nucleic Acids: - JOB: store & transmit genetic information
-Elements: C, H, O, P, N
-Subunit: nucleic acids are made out of nucleotide
- a nucleotide is made up of 3 things:
1.sugar 2. phosphate 3. base
-Shape & Examples:
-RNA- stands for Ribonucleic Acid
RNA looks like this
-DNA- stands for Deoxyribonucleic Acid
DNA looks like this
ORGANIC MOLECULES
Carbohydrates Proteins Lipids Nucleic Acids
Made of Made of Made of Made of
C, H, O C, H, O, N, S C, H, O, P C, H, O, P, N
Keratin,
hemoglobin,
enzymes
Sugars
Fats
(saturated/
unsaturated)
DNA /
RNA
examples examples examples examples
How are Organic Molecules made and broken down? How Organic Molecules are made:
- Dehydration Synthesis- -process of building organic molecules by removing a molecule of water
How Organic Molecules are broken down:
-Hydrolysis- process of breaking down
organic molecules by
adding a molecule of water
ENZYMES:
-A.k.a.: catalyst
-Made out of protein
-Typically end in ‘ase’
-Job: to speed up chemical reactions
by lowering the activation energy needed
-Enzymes work on a substance called a substrate (they fit together like 2
puzzle pieces)
-The enzyme and the substrate join at the active site
-This is where a chemical reaction takes place
-Then the product is released
-The enzyme is now free to find another substrate
Factors that can affect how an enzyme works:
2 Major factors that affect how enzymes work are:
1. Temperature-
• Enzymes work at specific temperatures
• If that temperature changes, it can denature an enzyme, which
means it can’t work anymore!
2. pH-
• this measures acidity levels
• the scale is: 0 to 14
•0-6 = acid
•7 = neutral
• 8-14 = base
• enzymes work at specific pH levels
• If that pH level changes, it can denature an
enzyme, which means it can’t work anymore!