End Show 2-1 The Nature of Matter Slide 1 of 40 Biochemistry Notes Copyright Pearson Prentice Hall

End Show 2-1 The Nature of Matter Slide 2 of 40 Copyright Pearson Prentice Hall Atoms The study of chemistry begins with the basic unit of matter, the atom.

End Show 2-1 The Nature of Matter Slide 3 of 40 Copyright Pearson Prentice Hall Atoms The subatomic particles that make up atoms are protons neutrons electrons

End Show 2-1 The Nature of Matter Slide 4 of 40 Copyright Pearson Prentice Hall Elements and Isotopes A chemical element is a pure substance that consists entirely of one type of atom. The number of protons in an atom of an element is the element's atomic number. Atomic Mass is the number of protons plus the number of neutrons in an atom

End Show 2-1 The Nature of Matter Slide 5 of 40 Copyright Pearson Prentice Hall Elements and Isotopes Isotopes Atoms of the same element that differ in the number of neutrons they contain are known as isotopes. Because they have the same number of electrons, all isotopes of an element have the same chemical properties.

End Show 2-1 The Nature of Matter Slide 6 of 40 Copyright Pearson Prentice Hall Chemical Compounds A chemical compound is a substance formed by the chemical combination of two or more elements in definite proportions.

End Show 2-1 The Nature of Matter Slide 7 of 40 Copyright Pearson Prentice Hall Chemical Bonds The atoms in compounds are held together by chemical bonds. The electrons that are available to form bonds are called valence electrons(electrons in the outermost orbit).

End Show 2-1 The Nature of Matter Slide 8 of 40 Copyright Pearson Prentice Hall Chemical Bonds The main types of chemical bonds are: ionic bonds covalent bonds

End Show 2-1 The Nature of Matter Slide 9 of 40 Copyright Pearson Prentice Hall Chemical Bonds Ionic Bonds An ionic bond is formed when one or more electrons are transferred from one atom to another. These positively and negatively charged atoms are known as ions.

End Show 2-1 The Nature of Matter Slide 10 of 40 Copyright Pearson Prentice Hall Chemical Bonds Covalent Bonds Sometimes electrons are shared by atoms instead of being transferred.

End Show 2-1 The Nature of Matter Slide 11 of 40 Copyright Pearson Prentice Hall The Water Molecule A water molecule is polar because there is an uneven distribution of electrons between the oxygen and hydrogen atoms.

End Show 2-1 The Nature of Matter Slide 12 of 40 Copyright Pearson Prentice Hall The Water Molecule Cohesion is an attraction between molecules of the same substance. Because of hydrogen bonding, water is extremely cohesive.

End Show 2-1 The Nature of Matter Slide 13 of 40 Copyright Pearson Prentice Hall The Water Molecule Adhesion is an attraction between molecules of different substances. Capillary action

End Show 2-1 The Nature of Matter Slide 14 of 40 Copyright Pearson Prentice Hall Solutions and Suspensions Solutions A mixture is a material composed of two or more elements or compounds that are physically mixed but not chemically combined.

End Show 2-1 The Nature of Matter Slide 15 of 40 Copyright Pearson Prentice Hall Acids, Bases, and pH The pH scale Chemists devised a measurement system called the pH scale to indicate the concentration of H + ions in solution. The pH scale ranges from 0 to 14.

End Show 2-1 The Nature of Matter Slide 16 of 40 Copyright Pearson Prentice Hall Acids, Bases, and pH At a pH of 7, the concentration of H + ions and OH - ions is equal. The pH Scale Human blood Milk Sea water Normal rainfall Pure water

End Show 2-1 The Nature of Matter Slide 17 of 40 Copyright Pearson Prentice Hall Acids, Bases, and pH Buffers The pH of the fluids within most cells in the human body must generally be kept between 6.5 and 7.5. Controlling pH is important for maintaining homeostasis.

End Show 2-1 The Nature of Matter Slide 18 of 40 Copyright Pearson Prentice Hall The Chemistry of Carbon Organic chemistry is the study of all compounds that contain bonds between carbon atoms.

End Show 2-1 The Nature of Matter Slide 19 of 40 Copyright Pearson Prentice Hall Macromolecules Macromolecules are formed by a process known as polymerization(dehydration Synthesis). Monomers Polymers Macromolecules are broken down by digestion(hydrolysis)

End Show 2-1 The Nature of Matter Slide 20 of 40 Copyright Pearson Prentice Hall Macromolecules Four groups of organic compounds found in living things are: carbohydrates lipids nucleic acids proteins

End Show 2-1 The Nature of Matter Slide 21 of 40 Copyright Pearson Prentice Hall Carbohydrates What is the function of carbohydrates? Source of Energy Structure Different sizes of carbohydrates: Monosaccharides Disaccharides Polysaccharides

End Show 2-1 The Nature of Matter Slide 22 of 40 Copyright Pearson Prentice Hall Carbohydrates Carbohydrates are compounds made up of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1 : 2 : 1.

End Show 2-1 The Nature of Matter Slide 23 of 40 Copyright Pearson Prentice Hall Lipids Lipids are generally not soluble in water. The common categories of lipids are: fats oils waxes steroids Lipids can be used to store energy. Some lipids are important parts of biological membranes and waterproof coverings.

End Show 2-1 The Nature of Matter Slide 24 of 40 Copyright Pearson Prentice Hall Nucleic Acids Nucleic acids are polymers assembled from individual monomers known as nucleotides.

End Show 2-1 The Nature of Matter Slide 25 of 40 Copyright Pearson Prentice Hall Nucleic Acids Nucleotides consist of three parts: a 5-carbon sugar a phosphate group a nitrogenous base

End Show 2-1 The Nature of Matter Slide 26 of 40 Copyright Pearson Prentice Hall Nucleic Acids Nucleic acids store and transmit hereditary, or genetic, information. ribonucleic acid (RNA) deoxyribonucleic acid (DNA)

End Show 2-1 The Nature of Matter Slide 27 of 40 Copyright Pearson Prentice Hall Proteins Proteins are macromolecules that contain nitrogen, carbon, hydrogen, and oxygen. polymers of molecules called amino acids.

End Show 2-1 The Nature of Matter Slide 28 of 40 Copyright Pearson Prentice Hall Proteins Amino acids – monomer of protein The portion of each amino acid that is different is a side chain called an R-group.

End Show 2-1 The Nature of Matter Slide 29 of 40 Copyright Pearson Prentice Hall Proteins The instructions for arranging amino acids into many different proteins are stored in DNA. Amino Acids Protein Molecule

End Show 2-1 The Nature of Matter Slide 30 of 40 Copyright Pearson Prentice Hall Proteins Some functions of proteins: –Control rate of reactions – Enzymes –Used to form bones and muscles –Transport substances into or out of cells –Help to fight disease - antibodies

End Show 2-1 The Nature of Matter Slide 31 of 40 Copyright Pearson Prentice Hall Enzymes Some chemical reactions that make life possible are too slow or have activation energies. These chemical reactions are made possible by catalysts. Enzymes speed up chemical reactions that take place in cells.

End Show 2-1 The Nature of Matter Slide 32 of 40 Copyright Pearson Prentice Hall Enzyme Action The Enzyme-Substrate Complex Enzymes provide a site where reactants can be brought together to react, reducing the energy needed for reaction. The reactants of enzyme-catalyzed reactions are known as substrates.

End Show 2-1 The Nature of Matter Slide 33 of 40 Copyright Pearson Prentice Hall Enzyme Action An Enzyme-Catalyzed Reaction

End Show 2-1 The Nature of Matter Slide 34 of 40 Copyright Pearson Prentice Hall Enzyme Action Regulation of Enzyme Activity Enzymes can be affected by any variable that influences a chemical reaction. pH values Changes in temperature Enzyme or substrate concentrations

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