Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Atoms An is the smallest unit of matter that cannot be broken down by chemical means. An atom consists of three kinds of particles: electrons (negative& around nucleus), protons (positive & in nucleus), and neutrons (neutral ) Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Nature of Matter Chemistry Atoms have parts: Nucleus – center, contains protons – has Electrons – lots of ENERGY – located around the nucleus – floating in “clouds” or “ ”

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Atoms, continued Elements An is a pure substance made of only one kind of atom. Elements differ in the number of protons their contain. The number of neutrons in an atom is often but not always equal to the number of in the atom. Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Bonding Atoms can join with other atoms to form stable substances. A force that joins atoms is called a bond. A is a substance made of the joined atoms of two or more different elements. Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Bonding, continued Covalent Bonds Covalent bonds form when two or more atoms share electrons to form a A molecule such as the water molecule shown below, is a group of atoms held together by Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Molecule Section 1 Nature of Matter Chemistry Living things are made mostly of, so water chemistry is very important to them! Most important (abundant) biological elements =

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Bonding, continued Covalent Bonds The arrangement of their electrons determines how atoms An atom becomes when its outer electron level is full. If the outer electron level is not full, an atom will react readily with atoms that can provide electrons to fill its outer level. Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Bonding, continued Hydrogen Bonds In a water molecule, the shared electrons are more strongly by the oxygen nucleus than by the hydrogen nuclei. Molecules with an unequal distribution of electrical charge, such as water molecules, are called This attraction between two water molecules is an example of a bond—a weak chemical attraction between polar molecules. Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Bonding, continued Hydrogen Bonds Water molecules are attracted to each other by These bonds are important because cells contain & are surrounded by water Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Hydrogen Bonding Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Bonding, continued Ionic Bonds Sometimes atoms or molecules gain or lose electrons. An atom or molecule that has gained or lost one or more electrons is called an Example – Ca is +2 Ions have an electrical charge because they contain an unequal number of electrons and protons. Ions of opposite charge may interact to form an Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chemical Bonding, continued Ionic Bonds Ionic bonds in sodium chloride,, are formed by the interaction between sodium ions, Na +, and chloride ions, Cl –. Ca (calcium) is an important biological ion with a charge of Section 1 Nature of Matter Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Water in Living Things Storage of Energy Many organisms release excess heat through water In organisms, this ability to control temperature enables cells to maintain a constant internal temperature when the external temperature changes. In this way, water helps cells maintain Section 2 Water and Solutions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Aqueous Solutions A is a mixture in which one or more substances are evenly distributed in another substance. Many important substances in the body have been dissolved in blood or other aqueous fluids. Because these substances can dissolve in water (polar things dissolve in polar things), they can more easily move within and cells. Section 2 Water and Solutions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Aqueous Solutions, continued Polarity The of water enables many substances to dissolve in water. When ionic compounds are dissolved in water, the ions become surrounded by water molecules. The resulting solution is a mixture of water molecules and Section 2 Water and Solutions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Aqueous Solutions, continued Polarity When sodium chloride, NaCl, is dissolved in water, sodium ions, Na +, and chloride ions, Cl –, become surrounded by molecules, H 2 O. Water = the, materials dissolved in a solvent are solutes. Section 2 Water and Solutions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Aqueous Solutions, continued Polarity molecules do not dissolve well in water. (cells contain and are surrounded by water) The inability of nonpolar molecules to dissolve in polar molecules is important to. For example, the shape and function of cell membranes depend on the interaction of polar water with nonpolar molecules. Section 2 Water and Solutions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Aqueous Solutions, continued Acids and Bases Compounds that form hydrogen ions when dissolved in water are called When an acid is added to water, the concentration of hydrogen ions in the solution is increased above that of water. Section 2 Water and Solutions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Aqueous Solutions, continued Acids and Bases Compounds that reduce the concentration of hydrogen ions in a solution are called Many bases form hydroxide ions when dissolved in water. Section 2 Water and Solutions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Aqueous Solutions, continued Acids and Bases The pH scale measures the concentration of hydrogen ions in a solution. COMPOUNDS ARE DIVIDED INTO 2 GROUPS: – Contain Carbon to Carbon bonds – Do not contain C-C bonds. Section 2 Water and Solutions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carbon (Organic) Compounds Carbohydrates are organic compounds made of carbon, hydrogen, and oxygen atoms in the proportion of 1:2:1. Carbohydrates are a key source of energy, and they are found in most foods—especially fruits, vegetables, and Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carbon Compounds, continued Carbohydrates The building blocks of carbohydrates are single sugars, called, such as glucose, C 6 H 12 O 6, and fructose. Simple sugars such as glucose are a major source of energy in cells. Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carbon Compounds, continued Carbohydrates are double sugars formed when two monosaccharides are joined., or common table sugar, is a disaccharide that consists of both glucose and fructose. Polysaccharides such as starch are chains of three or more Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carbon Compounds, continued Lipids are nonpolar molecules that are not soluble in water. They include fats, phospholipids, steroids, and waxes. Fats are lipids that A typical fat contains three fatty acids bonded to a glycerol molecule Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Fats Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carbon Compounds, continued Lipids In a saturated fatty acid, all of the carbon atoms in the chain are bonded to two hydrogen atoms (except the carbon atom on the end, which is bonded to hydrogen atoms). In an unsaturated fatty acid, some of the carbon atoms are linked by a “double” covalent bond, each with only one hydrogen atom, producing kinks in the Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Saturated and Unsaturated Fatty Acids Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carbon Compounds, continued Proteins A protein is a large molecule formed by linked smaller molecules called Amino acids are the building blocks of different amino acids are found in proteins. Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Structure of Proteins Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Proteins They make reactions They store and transport They make our muscles They carry nerve They give structure to our They protect us from Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Antibodies are in our blood that combine with other cells to fight invaders (antigens). To tell if you have an infection, lab tests can look for antibodies by using different tests including one that also identifies DNA. GEL ELECTROPHORESIS separates proteins (including antibodies) by weight as they are forced through a gel by.. Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carbon Compounds, continued A has three parts: a sugar, a base, and a phosphate group, which contains phosphorus and oxygen atoms. Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Nucleotide Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carbon Compounds, continued Nucleic Acids There are two types of nucleic acids —and each type contains four kinds of nucleotides. DNA, or acid, consists of two strands of nucleotides that spiral around each other. RNA, or ribonucleic acid, consists of a single strand of Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Structure of Nucleic Acids Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carbon Compounds, continued ATP or adenosine triphosphate, is a single nucleotide with two extra energy-storing phosphate groups. When food molecules are broken down inside cells, some of the energy in the molecules is stored temporarily in Section 3 Chemistry of Cells Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Energy for Life Processes Energy is the ability to move or change matter. Energy exists in —including light, heat, chemical energy, mechanical energy, and electrical energy—and it can be converted from one form to another. Energy can be stored or released by chemical Section 4 Energy and Chemical Reactions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Energy for Life Processes, continued Energy in Chemical Reactions In chemical reactions, energy is absorbed or released when chemical bonds are broken and new ones are formed. is the term used to describe all of the chemical reactions that occur within an organism. Section 4 Energy and Chemical Reactions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Enzymes Enzymes are substances that increase the speed of chemical reactions. Most enzymes are proteins. Enzymes are, which are substances that reduce the activation energy of a chemical reaction. Section 4 Energy and Chemical Reactions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Enzyme Activity Section 4 Energy and Chemical Reactions Chemistry

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu CHEMISTRY IN ACTION!. The CO 2 from the Diet Coke gets into the holes on the Menthos. Aspartane & caffeine increase the effect & the bubbles quickly rise to the top, bringing soda along. Chemistry