Chemistry In Biology Unit 2 Chapter 6

Goals

Identify The particles that make up atoms

Diagram The particles that make up an atom

Compare Covalent bonds Ionic bonds

6.1

Atoms, Elements and Compounds

Atoms The building blocks of matter Matter is anything that takes up space Chemistry is the study of matter

Structure of atoms Nucleus Protons Electrons Neutrons

Structure of atoms Nucleus Protons Electrons Neutrons

Structure of atoms Nucleus Protons (p+) Electrons (e-) Neutrons (n0)

Atoms Electrons are constantly moving around in orbits Structure based on attraction of protons and electrons Overall charge is zero

Elements A pure substance that cannot be broken down into other substances Not physically nor chemically Made up of one type of atom

Elements Over 100, 92 occur naturally Each has a unique name and symbol 97 is important to me

Periodic Table Elements are in blocks Periods and groups Similar chemical or physical properties Organic material H,C,O,N Earth’s crust O, Ca+Mg, Na+K, Si

Isotopes Atom with a different number of neutrons Same chemical properties

Radioactive Isotopes When a nucleus breaks apart Gives off radiation Carbon-14 is found in all living things

Compounds A pure substance Two or more elements combine

Compounds A pure substance Two or more elements combine Chemical formula

H2O

H2O

C8H10N4O2

C8H10N4O2

C6H12O6

C6H12O6

C6H12O6

Compounds Can not be broken down into simpler compounds or elements by physical means Can chemically

Chemical Bonds Force that holds substances together

Covalent Bonds Share an electron Both benefit H2O Molecule is a compound where atoms are held by covalent bonds

H2O

Ionic Bonds Ion – has given up or taken an electron to become stable Attraction between two oppositely charged atoms or groups of atoms Sodium, potassium, calcium, chloride and carbonate ions

Van der Waals Force The strength of the attraction depends on The size of the molecule The shape of the molecule The ability to attract

What happens to chrome near the beach? Or metal over time?

6.2

Chemical Reactions Rxn

Chemical Reactions Grow, reproduce, and adapt Process by which atoms or groups of atoms in substances are reorganized into different substances Bonds are broken Bonds are formed

Chemical Reaction has occurred? Shiny – dull Metal – orange Heat Light Formation of a gas, liquid or solid

Chemical formula Reactants and products C6H12O6 + O2 ------> CO2 + H2O Must balance equation!!!!!

Activation Energy The minimum amount of energy needed for reactants to form products A candle

Enzymes Special proteins Biological catalysts Doesn’t get used up

Catalyst Something that lowers the activation energy to start a reaction

Substrate Reactant that binds to the enzyme

Activation Site Specific location where a substrate binds on an enzyme

What causes tomatoes to ripen slowly in the fridge?

6.3

Water and Solutions Water’s polarity Polar molecules – have an unequal distribution of charges Hydrogen bond – weak bond = strong van der Waal’s

Polarity Differential distribution Tendency to develop form opposite poles Unevenly distributed

Water

Mixtures with water Mixture – combination of two or more substances in which each substance retains its individual characteristics Solution – homogeneous equal throughout Solvent – solution solute dissolved in Solute – is dissolved

Acid Substance that releases hydrogen ion when dissolved in water The more H+ released the stronger the Acid

Base Substances that release hydroxide ions when dissolved in water The more OH- the stronger the base NaOH

pH Measurement of concentration of H+ Neutral has pH of 7.0 Low acid High base

Buffers Mixture that can react with acids or bases to keep the pH within a particular range Cell buffers pH 6.5 to7.5 Blood buffers pH 7.4

6.4

Building Blocks of Life Organisms are made up of carbon-based molecules

Carbon Most biological molecules have as a component

Organic Chemistry Study of organic compounds

Macromolecules Large molecule Smaller organic molecules joined together

Polymers Repeating units of identical compounds Linked by covalent bonds

Carbohydrates Store energy Provide structural support One oxygen Two hydrogen For each carbon

Carbohydrates Grain Pasta, rice, bread,starches

Lipids Store energy Provide barriers

Lipids Fats

Proteins Transport Speed up Rxn Structural support Make hormones

Proteins Meat Beans

Nucleic Acids Store and communicate genetic information

Nucleic Acids DNA