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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings BIO 1110- Biochemistry
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Composition of Matter The “stuff” of the universe Anything that has mass and takes up space Made of elements
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Elements – Unique substances that cannot be broken down into simpler substances by chemical methods.
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings What 4 elements make up 96% of the body?
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Atoms – Building blocks of elements Every element’s atoms differ from all other elements. Differences in atoms give each element different physical and chemical properties.
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Atomic Structure Atoms are made of subatomic particles. + + - -
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings 2 electrons2 protons Charges balanced In an uncharged atom, the number of _______ and the number of _______ are _______. - - + + He
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Molecules and Compounds Molecule- A combination of 2 or more atoms held together by chemical bonds. The atoms can be the same (H 2 ) or different (H 2 O). Compound- A type of molecule formed by a combination of 2 or more different kinds of atoms like H 2 O.
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings is a water molecule. Water is a compound. is a hydrogen gas molecule. Hydrogen gas is not a compound. All compounds are made of molecules, but not all molecules are compounds.
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Bonds Electron shells, or energy levels, surround the nucleus of an atom. Bonds are formed using the electrons in the outermost energy level. Each energy level can hold a specific number of electrons.
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Filling Electron Shells Valence shell – Outermost electron energy level Octet rule – Except for the first shell which is full with two electrons, atoms interact in a manner to have 8 electrons in their valence shell (energy level) Will this atom interact with others? What about this one?
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Types of Bonds Ions- Charged atoms resulting from the gain or loss of electrons. Ionic bonds form between atoms by the transfer of one or more electrons
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
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Covalent Bonds Covalent bonds are formed by the sharing of two or more electrons. Electron sharing produces molecules.
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Hydrogen Bonds More like attractions than bonds Formed when a hydrogen atom (which is already covalently bonded to an atom) is attracted to another atom Causes surface tension in water
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Hydrogen Bonds in Water Figure 2.10a
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Organic Chemistry Molecules containing carbon Exception- CO, CO 2 & HCO 3 - because they are smaller, less complex molecules Carbon is special because it is electroneutral- never loses nor gains electrons but always shares electrons Building blocks of cells They include carbohydrates, lipids, proteins and nucleic acids They include carbohydrates, lipids, proteins and nucleic acids
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Carbohydrates: Sugars and Starches Contain carbon, hydrogen, and oxygen in a 1:2:1 ratio Monosaccharides: Simple sugars (glucose) Disaccharides: Double sugars- 2 monosaccharides bonded together (sucrose) Polysaccharides: Many sugars- Polymer of monosaccharides (starch)
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Major functions of carbs Used by cells to make ATP (cell energy) Extra carbs are stored in muscles and the liver as glycogen Cell identity markers
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Lipids Also contain C, H, and O but contains less O than carbs Functions include: Organ padding Energy storage Provide structure to the cell membranes Sex hormones
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Proteins Large molecules composed of combinations of 20 different amino acids. Functions include: Hormones Antibodies Cell membrane structure Muscle structure Enzymes Characteristics (hair color, skin color, eye color)
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structural Levels of Proteins Primary – Linear- Amino acid sequence Secondary – Twisted or bent primary structure
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structural Levels of Proteins Tertiary – superimposed folding of secondary structures Quaternary – Two or more protein chains linked together in a specific manner
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Enzymes Proteins that act as biological catalysts (speed up reactions) by lowering the energy needed for a chemical reaction (activation energy) Usually end in –ase Act on a substance called a substrate
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Mechanism of Enzyme Action Substrate binds to the enzyme at its active site. The enzyme and substrate fit together like a lock and key. The enzyme-substrate complex undergoes internal rearrangements that form the product(s). The enzyme releases the product(s). Enzyme is unchanged so it can act over and over again.
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Figure 2.21 Active site Amino acids Enzyme (E) Enzyme-substrate complex (E-S) Internal rearrangements leading to catalysis Dipeptide product (P) Free enzyme (E) Substrates (S) Peptide bond H2OH2O +
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Nucleic Acids Composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus Examples: DNA RNA ATP
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings DNA Genetic code: Tells the cells what proteins to make and when to make them. Found inside the nucleus.
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings RNA Complementary copy of the DNA code. Made in the nucleus and exits to the cytoplasm. Used as instructions for building proteins.
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Transcription and Translation Transcription= Making RNA from DNA Translation= Making proteins from RNA
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