1. Chapter 6
The Chemistry of Life

2. 6.1: Atoms and Their Interactions
You are responsible for this material! It is a review of material from Physical Science.
Use the 6.1 study guide questions worksheet to review this material.

3. 6.2: Water and Diffusion
Polar- molecule with an unequal distribution of charge, has a positive and negative end due to unequal sharing of electrons
Attracts ions
Attracts other polar molecules
Attracts other water molecules

5. Hydrogen bond- attraction of opposite charges between hydrogen and oxygen in water molecules
Gives water the ability to creep up thin tubes- capillary action
Gives water surface tension properties

6. Capillary action

7. Water resists temperature change
Specific heat- the amount of energy required to change one gram of material one degree Celsius
Water has a high specific heat
Helps maintain steady environment when situations fluctuate
Helps maintain homeostasis

8. Molecular Motion
Solids, liquids, and gases all have kinetic energy whether they are in motion or not
The molecules that make them up are in constant motion- Brownian motion
Temperature is a measure of this motion

9. Diffusion
Diffusion- the movement of particles from an area of higher to lower concentration
No energy required
Result of Brownian motion

10. Factors that affect the rate of diffusion:
1. Concentration gradient- difference in concentration of a substance across space
greater concentration gradient, faster diffusion
2. temperature- higher temperature means molecules move faster and bump into each other more often

11. 3. pressure- increasing pressure increases particle motion

12. How long does diffusion continue?
Until all areas are equal in concentration
Particles continue to move, but there is no overall concentration change
This is called dynamic equilibrium

13. Dynamic Equilibrium

14. 6.3: Life Substances
How many electrons does carbon have available for bonding in its outer energy level?
Because it can form 4 bonds, it makes a good backbone or skeleton on which to build larger molecules
Bonds easily with hydrogen,
oxygen, & nitrogen

15. Types of covalent bonds:
Carbon can bond with other carbon atoms & other elements to form:
Single- one pair of shared electrons
Double- two pairs of shared electrons
Triple- three pairs of shared electrons

16. When carbon atoms bond with each other, they can form:
Straight chains
Branched chains
Rings

17. Isomers- compounds with the same chemical formula but with different 3-dimensional structures
Organic compounds- contain at least one carbon chain

18. Macromolecules Monomers- fundamental molecular unit
Polymer- macromolecules formed by linking the same kind of functional unit

19. Carbohydrates Carbo- carbon Hydrate- water
Macromolecule composed of carbon, hydrogen & oxygen
General formula= (CH2O)n

20. Monosaccharide Monomer of carbohydrates Simple sugar
“ose” indicates that a substance is a sugar
Examples- glucose, fructose
Cells link monosaccharides
to form-

21. Disaccharides Sugar composed of 2 monosaccharides
Example- sucrose, lactose

22. Polysaccharides Polymers composed of many monosaccharides Examples:
Starch- long term energy storage
in plants, animals can break
down starch to obtain glucose

23. Glycogen- long term energy storage in animals, animals can break down glycogen to obtain glucose

24. Cellulose- AKA fiber, structural molecule in cell walls of plants and algae, animals cannot break it down

25. Lipids Functions- Energy storage Insulation Protective covering
Major component of cell membranes

26. Fats Energy storage molecules Mostly carbon and hydrogen
General formula= (CH2)n
Hydrophobic-
Hydro- water, Phobic- fearing
Triglyceride- glycerol
molecule & 3 fatty acids,
monomer of fats

27. Types of fats:
1. Saturated fats- no double bonds between carbon atoms in carbon
chains
Solid at room temperature-
butter, lard

28. 2. Unsaturated fats- double bonds between carbons in chain
Liquid at room temperature- oil

29. Phospholipids, waxes, and steroids
Phospholipids- major components of cell membranes
Waxes- hydrophobic coatings composed of fatty acid & alcohol
Steroids- cholesterol based,
important in digestion &
synthesis of male & female
hormones

30. Proteins
Composed of carbon, hydrogen, oxygen, nitrogen, (sometimes sulfur)
Functions:
Structural-hair, nails, horns, hooves
Contractile- produce movement, muscle
Storage- egg white
Defense- antibodies, membrane proteins
Transport- hemoglobin
Signaling- hormones, membrane proteins
Catalysts- enzymes

31. Amino Acids (AA) Monomer of proteins
Peptide bond- covalent bond between AA in protein chain (sometimes called polypeptides)
20 kinds of AA

33. Structure Determines Function
A protein is a chain of AA folded, twisted, & sometimes joined with other AA chains to form complex structures
A protein needs a particular shape to do its job

35. Enzymes
Proteins that act as catalysts and change the rate of a chemical reaction
Speed reactions in nearly all metabolic processes
Affected by:
Temperature
Ionic conditions- salt pH
Hint- if it ends in “ase”, it’s probably an enzyme!

36. Nucleic Acids- more in coming chapters
Macromolecules that contain information for the construction of proteins

37. Nucleotides Monomer of nucleic acids Structure- Phosphate group
5-carbon sugar
Nitrogenous base

38. DNA- deoxyribonucleic acid
Two chains of nucleotides
formed into a double helix
Genetic code found in
every cell

39. RNA- ribonucleic acid
Single chain of nucleotides wrapped around itself
Made from DNA and used in making proteins