Presentation on theme: "Chemistry of Life. I. Nature of Matter A. Atoms B. Chemical Bonding II. Water and Solutions A. Cohesion & Adhesion B. Polarity C. Acid & Bases."— Presentation transcript:
Chemistry of Life
I. Nature of Matter A. Atoms B. Chemical Bonding II. Water and Solutions A. Cohesion & Adhesion B. Polarity C. Acid & Bases
More Chemistry…. III. Chemistry of Cells A. Carbohydrates B. Lipids C. Proteins D. Nucleic Acids IV. Energy and Chemical Reactions A. Energy B. Enzymes
Atoms Smallest unit of matter that cannot be broken down by chemical means. Protons – (+) Neutrons – (0) Electrons – (-)
Element v. Compound Element – one kind of atom Compound – two or more different elements
Bonding…. Covalent: share electrons Shells….
More bonding… Hydrogen: occurs between polar molecules Water is a polar molecule: opposite ends of the molecule have opposite charges
Even more bonding… Ionic: gaining or losing electrons; become charged and…we know…opposites attract!
Cohesion, Adhesion, and Surface Tension Cohesion: molecules attracted to each other – causes surface tension Adhesion: molecules attracted to others – end up with capillary action. Cohesion and adhesion responsible for Giant Redwoods
Aqueous Solutions Solution: mixture where one or more substances are evenly distributed in another substance. Ex. Salt dissolves in water Polarity: polar easily dissolves in water; nonpolar does not dissolve well in water (oil and water)
Acids and Bases When a hydrogen is stripped away from a covalent bond it leaves as an ion H + (called a hydrogen ion), if it is stripped from a water molecule it leaves OH - a hydroxide ion Covalent bonds of water often break spontaneously-ionization – H 2 O H + + OH -
pH Scale Changes in acidity (or basicity) due to an increase or decrease in hydrogen ions are measured with the pH scale pH scale is used to determine the acidic or basic nature of a solution compared to pure water Pure water has an equal concentration of hydrogen and hydroxide ions pH = 7
Chemistry of Cells Organic compounds are found in living things – contain carbon and are covalently bonded. Four types: carbohydrates, lipids, protein, and nucleic acids.
Organics… Carbohydrates: C, H, O 1:2:1 (ex. Glucose – source of energy) Lipids: aka fats – nonpolar (remember the oil and water)… stores energy Proteins: chains of amino acids Nucleic acids: store and transmit heredity information – DNA, RNA ATP is the main source of energy in a cell.
Enzymes Starting a chemical reaction requires activation energy (energy to start activate). Enzymes speed up reactions by lowering activation energy.
More enzymes… Enzymes bind only certain substrates (in other words…they are picky!) pH and temperature affect enzyme activity… HOW?