1. The Chemistry of Life
Biology, Chapter 2

2. Elements Building blocks of matter
Pure substances that contain only one type of atom
examples
Hydrogen (H), Carbon (C), and Sodium (Na)
93% of the human body is made up of 3 elements: Oxygen, Hydrogen, and Carbon

3. Orbitals around the nucleus
The Nature of Matter
Atoms The basic unit of matter
Made up of subatomic particles
Protons
Neutrons
Electrons
Subatomic particle
Charge
Location
Protons +
positive
Nucleus
Neutrons
neutral
Electrons -
negative
Orbitals around the nucleus

5. Isotope  atoms of the same element with different numbers of neutrons
Radioactive isotopes  break down in predictable ways
Can be used to date fossils
Can be used for medical purposes

7. Compounds
Compound  a substance formed by the chemical combination of two or more elements in definite proportions.
Examples:
One example would be NaCl (sodium chloride or table salt).
Water, H2O is another example
There are 2 types of compounds
1) covalent
2) ionic

8. Chemical Bonds Atoms can bond in two ways:
Covalent bonds form when electrons are shared between atoms
These bonded atoms are called molecules
Ex: H20 (water), CO2
Covalently bonded atoms are called molecules

9. Ionic bonds form when one or more electrons are transferred from one atom to another
Ex: NaCl (table salt), FeO, (Iron oxide)

10. Characteristics of Water
Water is Polar.
Polar means that there is an uneven distribution of charge
Electrons are shared unevenly
Hydrogen bonds when polar molecules attract each other.
Weak bonds that give molecules special properties.

11. Ouch!

12. Cohesion  an attraction between molecules of the same substance
Adhesion  an
attraction between
molecules of
different substances
Capillary action  The movement of water against gravity, results form cohesion and adhesion

13. Why is water so important to life?
Ice floats
environment for aquatic organisms, thermal insulation
Resists changes in temperature
Ex. helps keep us cool, sweating
Capillarity
Trees
Solvent

14. Mixture  a material made up of two or more elements or compounds that are mixed together but not chemically combined.
Examples: Salt and pepper, Sugar and Sand

15. Solutions
In a solution all the components are evenly distributed throughout
Example: Saltwater
Solute – the substance that is dissolved (salt)
Solvent – the substance in which the solute is dissolved (water)
Concentration is the mass of solute in a given volume of solution (the amount of salt in the water)

16. Saturated solution  a solution that cannot accept any more solute
Aqueous solution  a solution where water is the solvent

17. Dissociation of Water H2O H+ + OH- OH- is called the hydroxide ion
H+ is called the hydrogen ion

18. Acids and Bases Acid  a solution that has more H+ ions than OH- ions
Tend to have a sour taste
Examples: Lemon juice, tomato juice, stomach acid
Can be corrosive

19. Bases have higher levels of OH- ions than H+ ions
Tend to feel slippery
Tend to have a bitter taste
Examples: Sea Water, Soap, Bleach

20. We measure Acidity and Basic levels using a pH scale.
Ranges from 0 to 14
7 is neutral, Acids are below 7, Bases are above 7
Buffers  weak acids or bases that can react with strong ones to prevent sharp sudden changes in pH

22. C arbon is Cool! Carbon is the element essential for life Why?
1) Can bond with a variety of other elements (including itself)
2) Can bond with up to 4 other atoms
3) Can store a lot of energy in bonds with other atoms
4) Is versatile (can form a lot of different types of molecules), can form multiple bonds (double and triple bonds)

23. Macromolecules Are: giant molecules
Made of: monomers smallest units of a macromolecule
Polymers many monomers joined together
4 types
1) carbohydrates 3) proteins
2) lipids 4) Nucleic acids
Macromolecule Video

24. Carbohydrates Examples:
Made up of  carbon, hydrogen, and oxygen atoms.
Function Used as the main source of energy for living things
Food examples: bread, potatoes, pasta, rice, cereal, sugar
Monomers: Monosaccharides, single sugar molecules.
Examples:
Glucose used for energy
Galactose  in milk
Fructose  in fruits
Disaccharides  2 monosaccharides hooked together
Sucrose  table sugar

26. Polysaccharides  made up of many monosaccharides
Examples
Glycogen energy stored in the muscles of animals
Starch  provides energy to plants
Cellulose  gives structure to plants

27. Draw a polysaccharide

28. Lipids Include: Fats, oils, waxes
Function energy storage, insulation, biological membranes, and waterproof coverings
Monomers: glycerol and fatty acids
Examples of lipids are olive oil, steroids, peanut oil
Saturated lipids: joined by a single bond and contain the maximum number of hydrogen atoms.
Unsaturated lipids: contain at least one carbon-carbon double bond.

29. Triglyceride

30. Nucleic Acids
Contain: hydrogen, oxygen, nitrogen, carbon, and phosphorus.
Monomers: nucleotides
3parts to the nucleotide
1) sugar 2) phosphate 3) Nitrogenous base
Function: store and transmit hereditary (genetic) information
There are two types:
-RNA (ribonucleic acid)
-DNA (deoxyribonucleic acid)

31. Proteins Examples: Fish, eggs, meat Functions: Monomers: amino acids
control the rate of reactions and regulate cell processes
Structured and support, form bones and muscles
Transport
Lots of others!
Monomers: amino acids
Represented by…
Polypeptide: many amino acids linked together
Another names for a protein

32. Specific examples of proteins
Hemoglobin carries oxygen in the blood
Insulin regulates blood sugar
Enzymes  biological catalysts
Draw a poly peptide:

33. Chemical Reactions and Enzymes
Chemical reaction  a process where one set of chemicals changes into another set
Reactants  the elements or compounds that enter into a chemical reaction.
Products  the elements or compounds produced by a chemical reaction.
CO2 + H20  H2CO3

34. Chemical reactions can be …
Endergonic
Absorb energy and store it for later
Exergonic
Release energy from food or stored sources
Endergonic reactions have a net __________________ of energy.
Exergonic reactions have a net __________________ of energy.

35. Activation energy  the energy needed to get a reaction started.
Most chemical reactions require the input of some energy to get started
Activation energy  the energy needed to get a reaction started.
A catalyst  a substance that speeds up the rate of a chemical reaction
Enzymes are used as biological catalysts

37. Enzymes 1) Speed up chemical reactions
2) Decrease the activation energy needed to get chemical reactions started
3) provide a site where reactants can be brought together to react
4) work by the lock and key method
5) are substrate specific
6) Can be turned on or off

40. Enzymes can be affected by
Temperature pH
Chemicals
 Significant changes in any of the above can cause the enzyme to become ineffective