Chapter 2 The Chemistry of Life

What We are Learning Today Section 1: The Nature of Matter Review atoms and element structure Identify the different ways chemicals bond Define Key Terms

Atoms The smallest unit of matter that cannot be broken down by chemical means Very small and always changing 3 particles make up an atom Electrons (-) Protons (+) Neutrons (neutral) Attract each other… *Therefore atom itself has no charge (negative electron cancels out positive proton)

Atomic Structure Electron Cloud made of electrons, which have (-) charge so Electron Cloud = (-) Nucleus made up of protons and neutrons, protons have (+) charge and neutrons have neutral (no) charge so nucleus has a (+) charge

Elements An element is a pure substance made of only one kind of atom Represented by chemical symbols (C, N, H) Elements differ in the # of protons (C=6, O=8) Equal to the atomic number Number of protons usually = number neutrons Are exceptions…

Differences in Elements Atomic Number all atoms of a particular element have the same number of protons which is called the atomic number. Ex: Helium = 2 b/c it has 2 protons

Chemical Bonding 3 Types Atoms can join together to form a stable substance The force that joins atoms together is called a chemical bond A compound is a mixture of the atoms of 2+ different elements joined together in a chemical bond 3 Types Covalent Hydrogen Ionic

Covalent bond When 2+ atoms share electrons to form a molecule. Arrangement of electrons determine how atoms bond together Electron levels Closest to nucleus = 2 electrons Second level = 8 electrons… Atom becomes stable when the outer electron level is full If it is not full it will react with atoms that can provide the electrons needed.

Atomic # = number of protons = # electrons Energy Levels Carbon Energy Levels Carbon = 6 electrons Atomic # = number of protons = # electrons 3 4 2 1 6 5

A Water Molecule has a POLAR Covalent Bond Water is made of Hydrogen and Oxygen Hydrogen =H 1 electron in its outer most level Oxygen =O 6 electrons in its outer most level They react to fill each ones outer most level 2 2 2 3 1 6 4 5

Hydrogen bonds Electrons in a water molecule are shared by oxygen and hydrogen atoms Electrons more strongly attracted to the oxygen nucleus than by the hydrogen’s This unequal distribution of electrical charge are called polar molecules

Polar Molecule (Water) Which pole attracts which pole?

Ionic Bonding Sometimes atoms or molecules gain or loose and electron Electric charge b/c they contain an unequal number of electrons and protons

Gaining/Losing an Electron Gaining Makes the atom more negative Adds a (-) charge onto the atom… electrons are (-) Losing Makes the atom more positive Adds a (+) charge onto the atom… negative charges were lost

Ionic Bond Example Na LOST an e- so it became more positive Cl GAINED an e- so it became more negative

Closure Carbon Do you remember anything about atoms? Make an atom of carbon using playdough Include the # protons, neutrons and electrons! Carbon 6

What did we learn today? Word Association Come to the board and write down any word you remember from today’s lesson!

QUIZ FRIDAY  quiz on Chapter 2 section 1 & 2 Period 12 Quiz THURSDAY

Exit Ticket Draw a carbon atom (Atomic number = 6) Label all the parts and correctly show the number of electrons in the right levels Write 3 things you learned today

Begin 2.1 Section Review Page 30 Questions 1-4 Finish for HW

Chapter 2 Section 2: Water & Solutions Water in Living Things Storage of heat Cohesion/ adhesion Aqueous Solutions Polarity Acids and Bases

Water and Solutions Notes Chapter 2 Section 2 Water and Solutions Notes

Water in Living Things 70% of your body is made of water Water helps move nutrients into and out of your cells Certain properties of water make it such an important substance for life Storage of heat Cohesion & Adhesion

Storage of Heat Water heats more slowly and retains heat longer than many other substances Many organisms release heat through water evaporation Sweating Helps maintain homeostasis

Cohesion & Adhesion Cohesion Adhesion Attraction between substances of the same kind Surface tension prevents water from breaking easily The hydrogen bonds between water molecules cause the cohesion of liquid water Adhesion Attraction between substances of a different kind Substances get wet Capillary action water molecules move up through a narrow tube (stem of plant) Because of these water can move up the stems of leaves

Aqueous Solutions Many substances dissolve in water Solution: a mixture in which one or more substances are evenly distributed in another substance Salt water Gatorade Because certain substances can dissolve in water they can more easily move throughout the body

Polarity Enables many substances to dissolve in water When ionic compounds are dissolved in water, ions become surrounded by polar water molecules Ions and molecules become evenly distributed in the water Non polar molecules do not dissolve in water well (oils)

Acids and Bases (H+) + (OH-)  WATER Pure water always has a low concentration of hydrogen ions (H+) and hydroxide ions (OH-) Compounds that form hydrogen ions when dissolved in water are acids Compounds that reduce the concentration of hydrogen ions in water are called bases lower the concentration of hydrogen ions because hydroxide ions react with hydrogen ions to form water (H+) + (OH-)  WATER

pH Scale

SECTION REVIEW QUESTIONS Chapter 2.2 Section Review Questions!

On your note sheets… Write at least 1 example of a Carbohydrate Lipid (fats) Protein Nucleic acid What do you think they all have in common?

Question #1 Which of the following is NOT an organic molecule? Carbohydrate Ice Lipid Nucleic Acid

Question #2 Write down 3 types of carbohydrates AND give examples of each (how many sugars in each) Monosaccharide- 1 sugar Disaccharide – 2 sugar Polysaccharide- 3 sugar (starch, cellulose, glycogen)

Index Card #3 Are lipids polar or non polar? Do they dissolve in water? no Give 3 examples of Lipids Steroids, fats, waxes

Card#4 What are the building blocks of proteins? Amino Acids Give 2 examples of proteins and where they are located in the body. Keratin- hair Hemoglobin- blood

Card 5 What is a fatty acid and which bio-molecule does it belong to? it is a lipid attached to a glycerol backbone It is a lipid

Card 6 Give 2 examples of carbohydrates produced by plants starch, cellulose Give 1 example of carbohydrates produced by animals. glycogen

Card 7 What are three characteristics of saturated fats? Solid at room temp Made from animal fats Straight chain

Card 8 What are 3 characteristics of unsaturated fats liquids at room temperature from plants structure is kinked because of the double carbon bond

Card 9 What are 2 examples of nucleic acids? DNA and RNA

10 What is the function of nucleic acids?

11 What is the function of lipids?

12 Which type of fat has a kink in the structure?

13 All organic compounds contain what element?

2.3 Chemistry of Cells Most matter in your body that isn’t water IS an organic molecule Organic = Carbon based 4 classes of organic molecules in your body (can’t function w/o them) Carbohydrates Lipids Proteins Nucleic Acids Structure Where its found Examples Function Other

Carbohydrates Organic molecules made of carbon, hydrogen and oxygen Structure Where its found Examples Function Other Organic molecules made of carbon, hydrogen and oxygen Major source of energy for the body Found in most foods (fruits, veggies, grain) in the form of sugars 3 types of sugars Monosaccharide (simple sugars; glucose & fructose) Disaccharide (double sugars; sucrose) Polysaccharide (3+monosaccharides; starch, glycogen)

Examples of Sugars (Carbs) Polysaccharides storehouses for energy starch, glycogen, cellulose Starch – made by plants Glycogen- made by animals Both made from linked glucose molecules (pg 34) Cellulose- made by plants (for structure) Structure Where its found Examples Function Other

Lipids Non-polar molecules… soluble or non-soluble? Fats, phospholipids, steroids and waxes Steroids (cholesterol, estrogen, testosterone) Important for structure and function of cell membranes Found in animal cell membranes & pigments Lipids store energy Structure Where its found Examples Function Other

Write this in OTHER! Structure Where its found Examples Function Other

Structure of Lipids 3 fatty acids bonded to a glycerol molecule backbone Fatty acid is long chain of carbon atoms with hydrogen bonded to them Strong bonds between carbon and hydrogen  can store lots of energy Structure Where its found Examples Function Other

Saturated and Unsaturated All carbons have single bonds to hydrogen Most animal fats Butter, lard, grease Usually solids at room temperature Unsaturated Some carbons linked by a double covalent bond Causes kinks in chain Plant oils, olive oil, fish oils Liquids at room temperature Structure Where its found Examples Function Other

Unsaturated Fats

Vocabulary! Complete Chapter 2.3 Vocabulary! HW if not finished!

What did we talk about yesterday? What is the name of compounds that contain carbon? What are the 3 types of carbohydrate “sugars?” What organism makes cellulose? What organism makes glycogen? Are lipids polar or non-polar? What are some examples of lipids? What is the difference between saturated and unsaturated fats?

Proteins Structure: Function: Where its found Examples Function Other Structure: Large molecules formed by linked smaller molecules called amino acids (AA) Function: AA are building blocks of proteins Only 20 AA Cause various shapes of proteins Some proteins are enzymes (help chemical reactions) Others used for structure Skin, ligaments, bone (Collagen) Hair & nails (keratin) Blood (hemoglobin)

Nucleic Acids Where Found Structure Function: Examples: All cells contain nucleic acids Structure Long chain of smaller molecules ( called nucleotides) 3 parts Sugar Base Phosphate group (P& O) Function: Store genetic info Examples: 2 types of nuclei acids DNA- deoxyribonucleic acid RNA- ribonucleic acid Structure Where its found Examples Function Other

Chapter 2.4 Energy & Chemical Reactions ability to move or change matter Many forms light, heat, chemical energy, mechanical energy, electrical energy Can be stored or released by chemical reactions (build/break bonds) Metabolism all of the chemical reactions that occur within an organism

Enzymes and Activation Energy amount of energy needed to start a reaction Can take a long time for reaction to occur Heat the substance? NO! Add a catalyst!! YES ENZYMES! Lower the amount of energy needed to start the reaction without changing the original reactants

Enzymes Shape specific Enzyme holds the reactant Fits like puzzle piece Active site Each enzyme has its own specific substrate (reactant) pH, Temperature, environment can affect

Section Review Questions 2.4 pg42 #1-4 Write the Questions & Answer

Complete 2.3 Directed Reading Worksheet Finish 2.4 Vocabulary Terms Complete 2.4 Directed Reading Sheet