1. The Structure and Function of Macromolecules

2. I. Polymers What is a polymer?
Poly = many; mer = part. A polymer is a large molecule consisting of many smaller sub-units bonded together.
What is a monomer?
A monomer is a sub-unit of a polymer.

3. A. Making and Breaking Polymers
How are covalent linkages between monomers formed in the creation of organic polymers?
Condensation or dehydration synthesis reactions.
Monomers are covalently linked to one another through the removal of water.

4. Condensation Synthesis

5. Hydrolysis What is a hydrolysis reaction?
Polymers are broken down into monomers.
Hydro = water; lysis = loosening/
Water is added and the lysis of the polymer occurs.

6. Hydrolysis

7. II. Classes of Organic Molecules:
What are the four classes of organic molecules?
Carbohydrates
Lipids
Proteins
Nucleic Acids

8. A. Carbohydrates Sugars
Carbo = carbon, hydrate = water; carbohydrates have the molecular formula (CH2O)n
Functions:
Store energy in chemical bonds
Glucose is the most common monosaccharide
Glucose is produced by photosynthetic autotrophs

9. 1. Structure of Monosaccharides
An OH group is attached to each carbon except one, which is double bonded to an oxygen (carbonyl).

10. Classified according to the size of their carbon chains, varies from 3 to 7 carbons.
Triose = 3 carbons
Pentose = 5 carbons
Hexose = 6 carbons

11. In aqueous solutions many monosaccharides form rings:

12. 2. Structure of Disaccharides
Double sugar that consists of 2 monosaccharides, joined by a glycosidic linkage.
What reaction forms the glycosidic linkage?
Condensation synthesis

13. Examples of Disaccharides:
Lactose = glucose + galactose
Sucrose = glucose + fructose

14. 3. Polysaccharides
Structure: Polymers of a few hundred or a few thousand monosaccharides.
Functions: energy storage molecules or for structural support:

15. Starch is a plant storage from of energy, easily hydrolyzed to glucose units
Cellulose is a fiber-like structureal material - tough and insoluble - used in plant cell walls
Glycogen is a highly branched chain used by animals to store energy in muscles and the liver.
Chitin is a polysaccharide used as a structural material in arthropod exoskeleton and fungal cell walls.

16. B. Lipids Structure: Greasy or oily nonpolar compounds Functions:
Energy storage
membrane structure
Protecting against desiccation (drying out).
Insulating against cold.
Absorbing shocks.
Regulating cell activities by hormone actions.

17. 1. Structure of Fatty Acids
Long chains of mostly carbon and hydrogen atoms with a -COOH group at one end.
When they are part of lipids, the fatty acids resemble long flexible tails.

18. Saturated and Unsaturated Fats
liquid at room temp
one or more double bonds between carbons in the fatty acids allows for “kinks” in the tails
most plant fats
Saturated fats:
have only single C-C bonds in fatty acid tails
solid at room temp
most animal fats

20. Saturated fatty acid

21. Unsaturated fatty acid

22. 2. Structure of Triglycerides
Glycerol + 3 fatty acids
3 ester linkages are formed between a hydroxyl group of the glycerol and a carboxyl group of the fatty acid.

23. 3. Phospholipids
Structure: Glycerol + 2 fatty acids + phosphate group.
Function: Main structural component of membranes, where they arrange in bilayers.

24. Phospholipids in Water

25. 4. Waxes
Function:
Lipids that serve as coatings for plant parts and as animal coverings.

26. 5. Steroids Structure: Four carbon rings with no fatty acid tails
Functions:
Component of animal cell membranes
Modified to form sex hormones

27. C. Proteins Structure: Polypeptide chains
Consist of peptide bonds between 20 possible amino acid monomers
Have a 3 dimensional globular shape

28. 1. Functions of Proteins
Enzymes which accelerate specific chemical reactions up to 10 billion times faster than they would spontaneously occur.
Structural materials, including keratin (the protein found in hair and nails) and collagen (the protein found in connective tissue).

29. Specific binding, such as antibodies that bind specifically to foreign substances to identify them to the body's immune system.
Specific carriers, including membrane transport proteins that move substances across cell membranes, and blood proteins, such as hemoglobin, that carry oxygen, iron, and other substances through the body.

30. Contraction, such as actin and myosin fibers that interact in muscle tissue.
Signaling, including hormones such as insulin that regulate sugar levels in blood.

31. 2. Structure of Amino Acid Monomers
Consist of an asymmetric carbon covalently bonded to:
Hydrogen
Amino group
Carboxyl (acid) group
Variable R group specific to each amino acid

32. Properties of Amino Acids
Grouped by polarity
Variable R groups (side chains) confer different properties to each amino acid:
polar, water soluble.
non-polar, water insoluble
positively charged
negatively charged.

33. 4 levels of protein structure:
primary
secondary
tertiary
quaternary

34. 3. Primary Structure Unique sequence of amino acids in a protein
Slight change in primary structure can alter function
Determined by genes
Condensation synthesis reactions form the peptide bonds between amino acids

36. 4. Secondary Structure
Repeated folding of protein’s polypeptide backbone
stabilized by H bonds between peptide linkages in the protein’s backbone
2 types, alpha helix, beta pleated sheets

38. 5. Tertiary Structure
Irregular contortions of a protein due to bonding between R groups
Weak bonds:
H bonding between polar side chains
ionic bonding between charged side chains
hydrophobic and van der Waals interactions
Strong bonds:
disulfide bridges form strong covalent linkages

40. 5. Quaternary Structure
Results from interactions among 2 or more polypeptides

42. Factors That Determine Protein Conformation
Occurs during protein synthesis within cell
Depends on physical conditions of environment
pH, temperature, salinity, etc.
Change in environment may lead to denaturation of protein
Denatured protein is biologically inactive
Can renature if primary structure is not lost

43. D. Nucleic Acids Two kinds: DNA: RNA: double stranded
can self replicate
makes up genes which code for proteins
is passed from one generation to another
RNA:
single stranded
functions in actual synthesis of proteins coded for by DNA
is made from the DNA template molecule

45. 1. Nucleotide Monomer Structure
Both DNA and RNA are composed of nucleotide monomers.
Nucleotide = 5 carbon sugar, phosphate, and nitrogenous base
Deoxyribose in DNA
Ribose in RNA

47. 2. Building the Polymer
Phosphate group of one nucleotide forms strong covalent bond with the #3 carbon of the sugar of the other nucleotide.

48. 3. Functions of Nucleotides
Monomers for Nucleic Acids
Transfer chemical energy from one molecule to another (e.g. ATP)

49. DNA:
Double helix
2 polynucleotide chains wound into the double helix
Base pairing between chains with H bonds
A - T
C - G

50. Summary of the Organic Molecules: