The Chemistry of Life

1
The Chemistry of Life Matter and Energy

• Chapter 2

2
The Nature of Matter

• Atoms
• Basic unit of matter
• Incredibly small (you could line up 100 million
  acros the width of your little finger)
• Made of three particles
• Protons positive charge, located in nucleus
• Neutrons no charge, located in nucleus
• Electrons negative charge, located around
  nucleus
• Usually electrically neutral (protonselectrons)

3
The Nature of Matter

• Elements and Isotopes
• Element pure substance, only one type of atom
• Atomic number number of protons in nucleus
• Isotope atoms of the same element that have
  different numbers of neutrons
• Mass number number of protons and neutrons in
  nucleus
• All isotopes of an element have the same chemical
  properties
• Radioactive isotopes nuclei are unstable and
  breakdown
• Used for geologic dating, cancer treatment,
  protection from bacterial outbreak in food etc

4
The Nature of Matter

• Chemical Compounds
• A substance formed by chemical combination of two
  or more elements
• Physical and chemical properties are different
  from the elements it is made of

5
The Nature of Matter

• Chemical bonds
• Created by interaction between electrons
• Two major types
• Ionic occur when electrons are transferred,
  causes an electrically charged atom (ion)
• Covalent occurs when electrons are shared
• Creates a molecule

6
Properties of Water

• The Water Molecule
• Found in an liquid state all over the planet
• Polarity unequal attraction between the shared
  electrons
• Hydrogen bonding attraction between molecules
  because of polarity
• cohesion
• Adhesion
• Heat capacity

7
Properties of Water

• Solutions and Suspensions
• Mixture physically mixed but NOT chemically
  combined
• Solution mixture where things are evenly
  distributed
• Solute substance that is dissolved
• Solvent substance in which solute dissolves
• Suspensions mixture of water and nondissolved
  material

8
Properties of Water

• Acids, Bases and pH
• pH scale measures concentration of H (hydrogen
  ion) in solution
• Ranges from 0 to 14
• 7 neutral
• Lower values acidic
• High values basic
• Buffers weak acids or bases that prevent sharp,
  sudden changes

9
Carbon Compounds

• The Chemistry of Carbon
• Carbon atoms have 4 valence electrons (outermost
  needed for reactions)
• Allows them to bond with many different elements
• Allows it to bond to itself to create long chains

10
Carbon Compounds

• Macromolecules
• Large molecules
• Created when monomers (single units) form
  polymers (multi-units)
• Four major types

11
Carbon Compounds

• Carbohydrates
• Made of carbon, hydrogen and oxygen
• Main source of energy for living things
• Can be used for structural purposes
• Simple sugars monosaccharides (glucose)
• Complex polysaccharides (glycogen and cellulose

12
Carbon Compounds

• Lipids
• Mostly carbon and hydrogen
• Used to store energy
• Important in membranes and waterproof coverings
• Referred to as saturated (solid) and unsaturated
  (liquid)

13
Carbon Compounds

• Nucleic acids
• Made of hydrogen, oxygen, nitrogen, carbon and
  phosphorus
• Store and transmit hereditary or genetic
  information
• Nucleotides monomers
• Two kinds RNA and DNA

14
Carbon Compounds

• Proteins
• Made of nitrogen, carbon, hydrogen, and oxygen
• Control the rates of reactions and regulates cell
  process
• Also used for structure and transport
• Amino acids monomer

15
Chemical Reactions and Enzymes

• Chemical Reactions
• A process that changes or transforms, one set of
  chemicals into another
• Changes in chemical bonds
• Reactants what is put into the reaction
• Products what is gotten out of the reaction

16
Chemical Reactions and Enzymes

• Energy in Reactions
• Either released or absorbed when bonds are formed
  or broken
• Energy sources examples
• Plants sunlight
• Animals consumption (eating) and digesting
• Activation energy energy needed to get a
  reaction started

17
Chemical Reactions and Enzymes

• Enzymes
• Specialized proteins
• Biological catalyst speeds up the rate of a
  chemical reaction
• Lower activation energy
• Very specific one enzyme one chemical reaction
• Substrates the reactants of an enzyme catalyzed
  reaction
• Bind at active site (lock and key)
• Affected by things such as temperature or pH