Chemistry Review

Chemistry Review Section 2.1 and 2.2

2.1 “Atoms, ions and molecules” • The ___________________is the smallest basic unit of matter • Atoms cannot be seen without an ____________________________ • It would take more than a trillion years to count all the atoms in a grain of sand!!!

The atom • There are three parts of a an atom

Elements • An is one particular type of , and it cannot be broken down into a simpler substance by ordinary chemical means • Gold • Aluminum • Helium

Key Elements • In biology, there are SIX very important elements • ________ • Hydrogen • _________ • Phosphorus • Sulfur • ________ NCHOPS

How are elements different • The number of protons determines the of an element • Carbon: 6 protons • Oxygen: 8 protons • The number of determines the property of an element • Carbon: 6 electrons, 4 on OUTSIDE • Oxygen: 8 electrons, 6 on OUTSIDE

Lonely Atoms • Atoms rarely are found alone in nature • They will do ANYTHING to get to electrons on the outside • Steal • Dump • Share

Compounds • A compound is a substance made of atoms of different bonded together • Result of sharing, stealing, or dumping electrons • Atoms bonded in a specific ratio

Carbon Compounds • Carbon can form many various ___________ to form • Carbohydrates • Proteins • Nucleic acids • Lipids

Ionic Bond • _________________ are formed through the electrical force between oppositely charged ions • Opposites attract! • Ex: Salt aka sodium chloride (NaCl) • Positive sodium (Na+) • Negative chloride (Cl-)

Ions • Ions are atoms that have gained or lost one or more . • Results in a change in electrical charge • Gain e- becomes ________________ • Lose e- becomes ________________

Covalent Bond • Not all atoms easily gain or lose their electrons! • Some atoms ___________ their electrons instead! • _______________ Bond:forms when atoms share a pair of electrons • Usually a very strong bond • Atoms may have several covalent bonds to share several electrons

Covalent Bond, cont. • Molecule: two or more atoms held together by bonds • Ex: carbon dioxide (CO2) • Carbon atoms needs 4 electrons to fill outer level, oxygen needs two • Carbon shares with 2 oxygen!

Ionic Bonds Covalent Bonds

SECTION 2.1 REVIEW • What distinguishes one element from another? • 2. Describe the formation of an ionic compound. • 3. What is the difference between and ionic bond and a covalent bond? • 4. How does a molecule differ from an atom?

Objectives • Life depends on hydrogen bonds in water. • Many compounds dissolve in water. • Some compounds form acids or bases.

THE IMPORTANCE OF WATER • Organisms’ bodies, (their _____________), • are made up of mostly ____________________ • The water in cells gives the cell _______________ • and ___________________ materials within • organisms. • All of the processes necessary for an • organism’s life take place within the • ______________________________ of the cell

PROPERTIES RELATED TO HYDROGEN BONDS • ______________________ • 2. ______________________ • 3. ______________________

Negative Charge HYDROGEN BONDS O • Water is a “______________” molecule • Form when atoms in a molecule have ____________ pulls on the _____________ they share. • Opposite charges of polar molecules can interact to form ____________________ bonds. • An attraction between a slightly _______________ hydrogen atom and a slightly ______________ atom. • (Usually _______________________________) • Hydrogen bonds are part of the structures of _______________ and of ______________ H H Positive Charge Positive Charge Shared Electrons

HIGH SPECIFIC HEAT • Hydrogen bonds give water an abnormally ____________________________. • Water __________________ changes in temperature because it must _____________ more ____________________ to increase in temperature.

COHESION Cohesion: the attraction among __________________ of the same substance. Cohesion from hydrogen bonds makes water molecules _____________________. Cohesion produces __________________, ( “skin on water” )

ADHESION Adhesion: the attraction among __________________ of ______________ substances. For example, water molecules stick to other things. Water in a test tube, (water is attracted to the ____________) ?

MOLECULES DISSOLVE IN WATER Materials such as ________________ and ____________ cannot be transported form one part of an organism to another unless they are dissolved in blood, plant sap, or other water based fluids. ______________: Mixture of a substance that is the same throughout. ___________: Substance that is present in the greater amount and dissolves another substance. ___________: Substance that dissolves in a solvent.

ACIDS AND BASES Some compounds form ______________ or _____________ because they _______________ into _______________ when they dissolve in ___________. BASE: Compounds that remove H+ ions from a solution ACID: Compounds that release a proton - a hydrogen ion(H+) – when it dissolves in water

SECTION 2.2 REVIEW • How do polar molecules form hydrogen bonds? • 2. What determines whether a compound will dissolve in water? • 3. Compare acids and bases. • 4. How do polar molecules differ from non-polar molecules? How does this difference affect their interactions? • 5. Describe an example of cohesion or adhesion that you might observe during your daily life.

Polymerization • Building large molecules (_________) from smaller ones (__________) • Several step process

Step 1: Get two monomers Both are _____________

Step 2: Bring them _____

Step 3: Add an enzyme

Step 3 • This __________ carries out a reaction between the two monomers • ___________ ___________: Joins two molecules together by REMOVING _______ • AKA: condensation reaction

Step 4: Bye Water! H2O ________

Step 5: A Dimer! REMEMBER, DIMER MEANS ________!

Step 6: Lather, Rinse, Repeat • The enzyme can carry out numerous dehydration synthesis reactions until a macro ___________ is created • EX: ______________ Each one of these monomers is ___________

Is this reversible? You better believe it!

Reversing Polymerization • Process called ____________. • “ __________” means water • “ __________” means to split or loosen • This enzyme works by _________ water to a polymer General process name: depolymerization turning polymers back into monomers

Bring in the Water! ENZYME H2O

And they are split apart! What was previous a dimer is now two ______________ again

BUILDING BLOCKS OF CELLS P ____________________ R L ____________________ O C I ____________________ ____________________ T P A A N E I R T ____________________ A P I D B N

Monomer & polymer • Each subunit of a complete carbon-based molecule is called a • A is a large molecule, or macromolecule, made of many monomers bonded together • Monomers of a polymer may be the same (ex. Starches) • Or different (proteins)

COMPOUND BUILDING BLOCK (POLYMER) (MONOMER) PROTEINAMINO ACID LIPID (FAT) FATTY ACID CARBOHYDRATESUGARS NUCLEIC ACIDS NUCLEOTIDE

Carbohydrates • Carbohydrates are molecules composed of carbon, , and oxygen • Include sugars & starches • Can be broken down to provide useable energy for cells • Major part of plant cell structure • The most basic carbs are simple sugars, • Polysaccharides are of monosaccharides

Proteins • Proteins are the most varied of the carbon-based molecules in organisms • Have a role in movement, eyesight, digestion,etc • A protein is a polymer made of monomers called amino acids • are molecules that contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur • Organisms use 20 different amino acids to build proteins • The body makes 12 of the 20, the other 8 come from food

Lipids • Lipids are nonpolar molecules that include fats, oils, and cholesterol • Contain chains of carbon bonded to oxygen & hydrogen • Energy storage • Phospholipids make up _____________________ • ________________ are chains of carbon atoms bonded to hydrogen atoms. • Saturated fatty acids have single carbon-carbon bonds (solid @ room temp) • Unsaturated fatty acids have double carbon-carbon bonds (liquid @ room temp)

ATP • MAJOR ___________ ___________ MOLECULE IN CELL. • ENERGY IN __________________ AND __________ AND _____________________ MUST BE TRANSFERRED TO ATP IN CELL TO BE USED.

Nucleic Acids • Detailed instructions to build proteins are stored in extremely long carbon-based molecules called nucleic acids • ____________________ are polymers that are made up of monomers called nucleotides • HAVE ALL INFO NEEDED TO MAKE __________. • “_______________” OF LIFE. • BUILDING BLOCKS OF _____________. • TWO TYPES: ________ AND _______.

SECTION 2.3 REVIEW • What is the relationship between a polymer and a monomer? • 2. Explain how both nucleic acids and proteins are polymers. Be sure to describe the monomers that make up the polymers. • 3. How are carbohydrates and lipids similar? How are they different? • 4. Explain how the bonding properties of carbon atoms result in the large variety of carbon-based molecules in living things?

Chemical Reactions • Bonds & during chemical reactions • Plant/Animal cells break down sugars to get usable energy • Cells build protein molecules by bonding amino acids together • Chemical reactions change substances into different substances by breaking and forming chemical bonds

Chemical Reactions • are the substance changed during a chemical reactions • Oxygen (O2) & Glucose (C6H12O6) • are the substances made by a chemical reaction • Carbon Dioxide (CO2) & Water (H2O) 6O2 + C6H12O6 6CO2 + 6H2O • Reactants • Products

It’s all about the energy • Energy is __________ to break bonds in molecules • Energy is ___________ when bonds are formed needed released

Chemistry Review