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Chemistry, Water and Enzymes
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Daily Question Thursday, September 19 1. Calculate the number of atoms in Al 2 (SiO 3 ) 2 2.Describe how you figure out how many neutrons a particular atom has? 3. What makes water polar? 4. Describe why water molecules are attracted to each other. 5. What is the difference between cohesion and adhesion?
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Organic Compounds
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Carbohydrates Carbon, Hydrogen, and Oxygen Monosaccharides are building blocks –Glucose, fructose Polysaccharides: when many monosaccharides are linked together Can store energy for cells
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Lipids Nonpolar Not soluble in water Fats, oils, steroids, and waxes Important to cell membrane Some store energy
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Proteins Made of amino acids Promote chemical reactions, structural purposes, fight infections, support movements
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Nucleic Acid Chain of nucleotides (sugar, base, and phosphate group) DNA, RNA
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Chemistry
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Structure of an Atom The nucleus of a helium atom contains 2 neutrons, shown in purple and 2 protons, shown in green. 2 electrons move around the nucleus at very extreme speeds.
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Chemistry Basics Matter: anything that occupies space and has mass. Mass: how much matter something has. Atom: basic unit of matter. Nucleus: center, contains protons (+) and neutrons (0). electrons (-) move around the nucleus at tremendous speed.
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Chemistry Basics Element: a substance made of only one kind of atom. Pure matter. Compound: atoms of two or more elements chemically combined.
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Chemical Bonding
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The arrangement of electrons determines how the atoms bond together. IMPORTANT: *all atoms (except H and He) have outer energy levels (shells) that can hold up to 8 electrons. *an atom becomes stable (happy!) when its outer energy shell has 8 electrons. *if outer shell is not full, the atom will react with other atoms that can provide electrons to fill its outer shell. *the outer shell reaches a stable state (happy!) by losing, gaining, or sharing electrons with other atoms.
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Ionic Bonding Ionic Bonds: when atoms gain or lose electrons to form ions (charged particles).
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Covalent Bonding Covalent Bond: when two or more atoms share electrons to form a molecule. In a water molecule, each hydrogen atom forms a covalent bond with the oxygen atom.
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Properties of Water
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Water and Polarity Each water molecule is held together by covalent bonds between 2 hydrogen atoms and 1 oxygen atom. The shared electrons are attracted more strongly by the oxygen nucleus than by the hydrogen. Therefore, water has positive and negative ends. Polar molecules: have unequal distribution of electrical charge. Hydrogen bond: weak chemical attraction between molecules.
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Hydrogen Bonds in Water Hydrogen bonds form between water molecules.
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Properties of Water 1.Polarity 2.Surface Tension (cohesion: attraction between molecules of the same substance) Creeps up thin tubes (adhesion: attraction between molecules of different substances)
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Acids, Bases, and pH Water can break apart into 2 charged ions: H 2 OH + +OH - WaterHydrogen ionHydroxide ion Acid: a compound that forms H+ in solution. Base: a compound that forms OH- in solution. Solution: a mixture in which one or more substances are evenly distributed in another substance.
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pH scale Base: 8 -14 Neutral: 7 Acid: 0 - 6
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Chemistry
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Structure of an Atom The nucleus of a helium atom contains 2 neutrons, shown in purple and 2 protons, shown in green. 2 electrons move around the nucleus at very extreme speeds.
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Chemistry Basics Matter: anything that occupies space and has mass. Mass: how much matter something has. Atom: basic unit of matter. Nucleus: center, contains protons (+) and neutrons (0). electrons (-) move around the nucleus at tremendous speed.
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Chemistry Basics Element: a substance made of only one kind of atom. Pure matter. Compound: atoms of two or more elements chemically combined.
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Chemical Bonding
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The arrangement of electrons determines how the atoms bond together. IMPORTANT: *all atoms (except H and He) have outer energy levels (shells) that can hold up to 8 electrons. *an atom becomes stable (happy!) when its outer energy shell has 8 electrons. *if outer shell is not full, the atom will react with other atoms that can provide electrons to fill its outer shell. *the outer shell reaches a stable state (happy!) by losing, gaining, or sharing electrons with other atoms.
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Ionic Bonding Ionic Bonds: when atoms gain or lose electrons to form ions (charged particles).
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Covalent Bonding Covalent Bond: when two or more atoms share electrons to form a molecule. In a water molecule, each hydrogen atom forms a covalent bond with the oxygen atom.
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Properties of Water
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Water and Polarity Each water molecule is held together by covalent bonds between 2 hydrogen atoms and 1 oxygen atom. The shared electrons are attracted more strongly by the oxygen nucleus than by the hydrogen. Therefore, water has positive and negative ends. Polar molecules: have unequal distribution of electrical charge. Hydrogen bond: weak chemical attraction between molecules.
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Hydrogen Bonds in Water Hydrogen bonds form between water molecules.
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Properties of Water 1.Polarity 2.Surface Tension (cohesion: attraction between molecules of the same substance) Creeps up thin tubes (adhesion: attraction between molecules of different substances)
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Acids, Bases, and pH Water can break apart into 2 charged ions: H 2 OH + +OH - WaterHydrogen ionHydroxide ion Acid: a compound that forms H+ in solution. Base: a compound that forms OH- in solution. Solution: a mixture in which one or more substances are evenly distributed in another substance.
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pH scale Base: 8 -14 Neutral: 7 Acid: 0 - 6
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