Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  Everything that happens in a living organism involves chemical reactions  Death occurs when these chemical reactions can no longer occur

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 2  Elements are made of a single kind of atom and cannot be broken down by chemical means into simpler substances.  Atoms are composed of protons, neutrons, and electrons.  Six elements (C, H, N, O, P, and S) are commonly found in living things.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Composition of Matter Chapter 2  Isotopes Atoms of the same element that have a different number of neutrons are called isotopes. A neutron has no charge, so there is no change in charge A neutron has mass, so the mass of an isotope is different  Since Isotopes have the same number of electrons, all isotopes of an element will have the same properties of an element

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu C-12 = _____ p + and _____ n 0 C-13 = _____ p + and _____ n 0 C-14 = _____ p + and _____ n 0

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  Radioactive or unstable isotopes due to an imbalance in the # of protons & neutrons.  What are some biological uses of radioisotopes?  a) Cellular tracers – Tract the movement of molecules  b) Medical testing – Brain scan, blocked arteries and intestines.  c) Biochemical analysis of blood or urine (hormones, drugs, antigens).  d) Medical treatments- treating cancer

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Composition of Matter Chapter 2 Compounds, continued Covalent Bonds –A covalent bond is formed when two atoms share electrons.

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Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Compounds, continued Ionic Bonds –An ionic bond is formed when one atom gives up an electron to another. The positive ion is then attracted to a negative ion to form the ionic bond.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  A chemical formula indicates the number of atoms in each substance; H 2 O contains 3 atoms (2 hydrogen and 1 oxygen) Subscript indicates the number of atoms

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  Matter is never created nor destroyed, only changed from one form to another Or  In a chemical reaction, the mass of the reactants is always equal to the mass of the products So A chemical equation always has to be balanced; the same number of each type of atom is on both sides.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu All chemical equations have three main parts  Reactants on the left side of the arrow  Arrow that is read as “yields”  Products are on the right side of the arrow Coefficient indicates the number of molecules; 6H 2 O is six molecules of water

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  Na + Cl 2  NaCl  H 2 + O 2  H 2 O  Zn + HCl  Zn 2 Cl + H 2  HgO  Hg + O 2  C 6 H 12 O 6 + O 2  H 2 O + CO 2 And Name the process this equation represents!

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Energy in living things Energy is stored in chemical compounds, and released when compounds are broken down and new ones are made from the existing atoms.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  Energy in the bonds of chemical formulas represents potential energy Plants store energy in a compound with many bonds, called starch Animals store energy in a similar compound, called glycogen Energy is transferred throughout all living things in a molecule called adenosine triphosphate, or ATP  Kinetic energy in living organisms occurs as chemical reactions occur, allowing for all the processes of living things to occur

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Energy Currency Adenosine triphosphate (ATP) stores and releases energy during cell processes, enabling organisms to function.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 2 Energy and Chemical Reactions, continued Activation Energy –Enzymes lower the amount of activation energy necessary for a reaction to begin in living systems.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 2 Section 2 Energy

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  Acts as a buffer for body temperature  Provides soluble environment for chemical reactions  Serves as a reactant in chemical reactions  Provides hydration that maintains cell turgidity  Maintains protein shape

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Polarity Water is considered to be a polar molecule due to an uneven distribution of charge. The electrons in a water molecule are shared unevenly between hydrogen and oxygen.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Polarity, continued Solubility of Water –The polarity of water makes it effective at dissolving other polar substances such as sugars, ionic compounds, and some proteins.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Hydrogen Bonding A hydrogen bond is the force of attraction between a hydrogen molecule with a partial positive charge and another atom or molecule with a partial or full negative charge.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Hydrogen Bonding, continued Temperature Moderation –Water has the ability to absorb a relatively large amount of energy as heat –This property is called specific heat, the amount of heat needed to raise the temperature of 1 gram of a material by 1 degree Celsius –and the ability to cool surfaces through evaporation.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Acids and Bases Ionization of Water –Water ionizes into hydronium ions (H 3 O + ) and hydroxide ions (OH – ). Acids –Acidic solutions contain more hydronium ions than hydroxide ions Bases –Basic solutions contain more hydroxide ions than hydronium ions

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Acids and Bases, continued pH –Scientists have developed a scale for comparing the relative concentrations of hydronium ions and hydroxide ions in a solution. This scale is called the pH scale, and it ranges from 0 to 14. –pH of 7 is neutral Buffers –Buffers are chemicals that neutralize the effects of adding small amounts of either an acid or a base to a solution.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  During exercise, muscles use up oxygen as they convert chemical energy in glucose to mechanical energy.  This causes chemical changes in the blood, which causes the pH of the blood to drop.  If the pH of the body gets too low (below 7.4), a condition known as acidosis results.  Ideal blood pH is 7.4.  If the pH drops below 6.8 or rises above 7.8, death may occur.  Buffers in the blood protect against large changes in pH.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 2 Section 3 Water and Solutions

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  Molecular Modeling

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Carbon Compounds Chapter 3  Organic compounds contain carbon atoms and are found in living things.  Most inorganic compounds do not contain carbon atoms.  Carbon atoms can readily form four covalent bonds with other atoms including other carbon atoms. The carbon bonds allow the carbon atoms to form a wide variety of simple and complex organic compounds.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 3 Section 1 Carbon Compounds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Carbon Compounds Chapter 3 Functional Groups Functional groups are groups of atoms that influence the properties of molecules and the chemical reactions in which the molecules participate. YOU MUST BE ABLE TO PICK THESE FOUR OUT ON A TEST

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Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu  Large molecules formed by polymerization, the process of small monomers or subunits joining together to form large macromolecules Be sure you know the monomer that makes up each group of macromolecule!  Four major groups of macromolecules found in living things Carbohydrates Lipids Nucleic acids Proteins

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Carbon Compounds Chapter 3 Macromolecules, continued Condensation reactions join monomers (small simple molecules) to form polymers. A condensation reaction releases water as a by-product. A condensation reaction is a type of synthesis reaction; it is also called dehydration synthesis A + B  C (in this case a small amount of water is also produced) In a hydrolysis reaction, water is used to split polymers into monomers. A hydrolysis reaction is a form of decomposition reaction C  A + B

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Carbohydrates Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen in a ratio of about one carbon to two hydrogen atoms to one oxygen atom. Carbohydrates are a source of energy and are used as structural materials in organisms.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Carbohydrates, continued Monosaccharides –Carbohydrates are made up of monomers called monosaccharides. Disaccharides and Polysaccharides –Two monosaccharides join to form a double sugar called a disaccharide. –A complex sugar, or polysaccharide, is made of three or more monosaccharides.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Proteins Proteins are organic compounds composed mainly of carbon, hydrogen, oxygen, and nitrogen. Proteins have many functions including structural, defensive, and catalytic roles. Amino Acids –Proteins are made up of monomers called amino acids. –The sequence of amino acids determines a protein’s shape and function.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Proteins, continued Dipeptides and Polypeptides –Two amino acids are joined by peptide bonds to form a dipeptide. –A long chain of amino acids is called a polypeptide.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 3 Section 2 Molecules of Life

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Proteins, continued Enzymes –Enzymes speed up chemical reactions and bind to specific substrates. –The binding of a substrate with an enzyme causes a change in the enzyme’s shape and reduces the activation energy of the reaction.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 3 Section 2 Molecules of Life

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Lipids Lipids are nonpolar molecules that store energy and are an important part of cell membranes. Because lipids are nonpolar, they are all insoluble in water. Fatty Acids –Most lipids contain fatty acids, unbranched carbon molecules that have a hydrophilic end and a hydrophobic end.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Lipids, continued Triglycerides –Triglycerides consist of three fatty acids and one molecule of glycerol.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Lipids, continued Phospholipids –Phospholipids, which make up cell membranes, consist of two fatty acids and one glycerol molecule.

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Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Lipids, continued Waxes –A wax is made of one long fatty acid chain joined to one long alcohol. Steroids –A steroid is composed of four fused carbon rings.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Steroids Cholesterol is required in the cell membranes of all cells, and is used to make testosterone, shown below

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Nucleic Acids A nucleic acid is a large and complex organic molecule that stores and transports information. Consists of subunits of nucleotides 3 parts of a nucleotide Nitrogen containing base Phosphate 5 carbon sugar

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 3 Section 2 Molecules of Life

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Molecules of Life Chapter 3 Nucleic Acids, continued The nucleic acid deoxyribonucleic acid (DNA) contains genetic information for cell activities. Ribonucleic acid (RNA) molecules play many key roles in building of proteins and can act as enzymes.