1. Chapter 5
The Molecules of Life

2. Water Water – makes up 70% of a cell’s weight
Most intracellular reactions occur in the aqueous environment

3. Water
Properties:
Inorganic Molecule – nonliving and does not contain C
Ex. H2O
Polar compound – one that has a more positive charge on one side, and a more negative charge on the other
Makes a great solvent; dissolves ions and other polar molecules easily
Dissolve

4. Hydrogen Bonds – weak attraction between a molecule with a negative charge (ex oxygen) and a hydrogen atom
Cohesion – tendency of the molecules of a substance to stick together
Adhesion – attractive force between unlike substances
Capillary action – ability to spread through narrow pores or tubes against gravity
Water is less dense at lower temperatures

5. Draw on your papers

6. Carbon Compounds Organic Compounds – contain C and living
Exceptions: graphite, diamonds, CO2
Carbon exhibits bonding power of 4 C
Most often bonds with hydrogen, oxygen, nitrogen, or to itself and forms chains
Hydrocarbon – long chains composed of hydrogen and carbon

7. Draw the example in your notes

8. Functional group – group of atoms within a molecule that interact with other molecules in a predictable way
Ex. See table

9. Ex: a sugar molecule in starch
Monomer - A single, repeated molecule unit
Ex: a sugar molecule in starch
Polymer – complex molecules consisting of repeated monomers
Macromolecules – large polymers (starch)
Condensation Reaction (dehydration synthesis) – process of bonding two monomers together by the removal of a H2O
Hydrolysis – process of breaking apart a complex molecule by the addition of a water molecule

11. The Four Biological Molecules
1. Carbohydrates – organic compound made up of sugar molecules
The most abundant of all biological molecules
Contain C, H, and O

12. Carbohydrates Monosaccharide (simple sugars) – one monomer of sugar
Cannot be hydrolyzed into a smaller unit, C6H12O6
Ex: Glucose, Fructose, Galactose
Isomers – Compounds that have the same exact molecular formula but differ in structure and function

13. Monosaccharide ISOMERS

14. Carbohydrates
Disaccharide – two monosaccharides joined together by a condensation reaction forming a double sugar, C12H22O11
Ex: Sucrose, Maltose, Lactose
Polysaccharides – complex carbohydrates made up of many joined monosaccharides
Ex: Cellulose – plants structure
Starch – plants store food
Glycogen – animals store food

15. Lipids 2. Lipids - Fatty hydrocarbon compounds also composed of C,H,O
Fats – lipid molecule that have 3 fatty acid tails attached to a glycerol molecule
Saturated – all single bonds therefore carbon is bonded to the maximum number of atoms
Unsaturated – double bonds appear therefore carbon is attached to fewer atoms

16. Fats Triglyceride

17. Saturated vs. Unsaturated

18. Lipids
Steroids – lipid molecule in which the carbon skeleton forms four fused rings
Ex: hormones, cholesterol, plant poisons

19. Draw a Phospholipid (makes up the cell membrane)

20. Proteins
3. Proteins – a polymer constructed from a set of just 20 kind monomers called amino acids
Most diverse group of the large biological molecules
Ex. Hair, fur, nails

21. Proteins Amino Acids – building blocks of proteins, 20
Structure of an amino acid
Carbon atom
Hydrogen atom
Carboxyl group
Amino group
R group

22. Proteins Peptide bonds – bond that links two amino acids together
Ex: Dipeptide – 2 amino acids joined together
Polypeptide – proteins of three or more amino acids
Proteins bend and fold to achieve the correct shape so that they can function
Denaturation – loss of normal shape of protein
Heat, pH, other environmental factors

24. Proteins
Enzymes – Class of proteins which act as catalysts by speeding up specific metabolic reactions by lowering the activation energy
Activation Energy – energy needed for a reaction to occur
Substrate – substance acted upon by enzyme
Active Site – particular region on an enzyme where a substrate binds

26. Nucleic Acids
4. Nucleic Acids – complex organic molecules made up of monomers of nucleotides
Ex: DNA – Deoxyribonucleic Acid
RNA – Ribonucleic Acid

27. Nucleic Acids Nucleotides – Small organic compound comprised of:
1. Phosphate group
2. 5-C sugar (pentose) – ribose
or deoxyribose
3. nitrogen base – adenine, guanine, cytosine, thymine

28. Organic Molecules Flipchart

29. Organic Compounds Video
Watch the video and answer the questions.