1. Macromolecules Goal
Know the structure and function of all 4 macromolecules

2. Macromolecules : The Molecules of Life
Within cells, small organic molecules called monomers are joined together to form larger molecules, known as Macromolecules.
Each cell has thousands of different kinds of macromolecules.
Macromolecules vary among cells of an organism, vary more within a species, and vary even more between species.

4. Function: What do macromolecules do?
Carbohydrates - short term energy storage; structure of some organisms
Lipids - (also known as fats) - long term energy storage
Nucleic Acids (DNA and RNA) - the instructions the cell uses to build proteins
Proteins (Polypeptides): The highly variable macromolecules that make each organism unique

5. Carbohydrates Sugars & Starches
Used for energy in all organisms and for structure in plants.

7. Sugars
Function: Monosaccharides serve as a major fuel for cells and as raw material for building molecules
Monosaccharides have molecular formulas that are usually multiples of CH2O – 1:2:1 ratio
Glucose is the most common monosaccharide
Structure: though often drawn as a linear skeleton, in aqueous solutions they form rings

8. LE 5-4
Linear and
ring forms
Abbreviated ring
structure

9. Monosaccharides (simple sugars)= monomer of carbohydrates
Mono- = one
• Glucose (C6H12O6) = sugar used as an energy source in all cells.
• Other Examples: Fructose (Fruit sugar) & Galactose (Milk sugar)

10. Disaccharides (sugars) = 2 monosaccharides linked together.
Di- = two
Examples: Lactose (milk sugar) & Sucrose
(table sugar)

11. Storage and Structure Polysaccharides 3 or more monosaccharides linked.
Poly- = Many
Glycogen = Used as energy storage in animals.
• Cellulose = Used to form the cell wall of plants.
Chitin- is found in the exoskeleton of arthropods and the cell walls of many fungi

12. Storage Polysaccharides
Starch, a storage polysaccharide of plants, consists entirely of glucose monomers
Plants store surplus starch as granules within chloroplasts and other plastids

13. Starch: a plant polysaccharide
LE 5-6a
Chloroplast
Starch
1 µm
Amylose
Amylopectin
Starch: a plant polysaccharide

14. Cellulose microfibrils in a plant cell wall
LE 5-8
Cellulose microfibrils
in a plant cell wall
Cell walls
Microfibril
0.5 µm
Plant cells
Cellulose
molecules
b Glucose
monomer

15. Enzymes that digest starch by hydrolyzing alpha linkages can’t hydrolyze beta linkages in cellulose
Cellulose in human food passes through the digestive tract as insoluble fiber
Some microbes use enzymes to digest cellulose
Many herbivores, from cows to termites, have symbiotic relationships with these microbes

18. Used for long-term energy storage.
Lipids (fats)
Steriods
Used for long-term energy storage.

19. Lipids are a diverse group of hydrophobic molecules
Lipids are the one class of large biological molecules that do not form polymers
The unifying feature of lipids is having little or no affinity for water
Lipids are hydrophobic becausethey consist mostly of hydrocarbons, which form nonpolar covalent bonds
The most biologically important lipids are fats, sterols and phospholipids.

24. When phospholipids are added to water, they self-assemble into a bilayer, with the hydrophobic tails pointing toward the interior
The structure of phospholipids results in a bilayer arrangement found in cell membranes
Phospholipids are the major component of all cell membranes

26. LE 5-14
WATER
Hydrophilic
head
Hydrophobic
tails
WATER

27. Steroids Considered lipids because they are hydrophobic!!
Consist of 4 fused rings
Cholesterol is a steroid

29. DNA – your genetic code RNA – used to make proteins
Nucleic Acids
DNA – your genetic code
RNA – used to make proteins

30. Nucleotide = monomer of nucleic acids.
Nucleotide has 3 parts:
- phosphate
- 5-carbon sugar
- nitrogen base.

31. DNA & RNA = Polymers of nucleic acids
DNA – di=2 (α-helix) carries the information on how to make proteins. Mostly 2 strands ( 1 found in viruses)
RNA is directly involved in making proteins.( mostly 1 , two found in viruses )

33. Proteins
The major building block in living things. Muscles, enzymes, antibodies, cell structure

34. Proteins have many structures, resulting in a wide range of functions
Proteins account for more than 50% of the dry mass of most cells
Protein functions include enzymes*,structural support, storage, transport, cellular communications, movement, and defense against foreign substances
Different functions=different shapes

36. Structure of Proteins
Protein = Polypeptide (polymer) comprised of monomers (amino acids). There are 20 different amino acids.
Amine Group (NH2)-Basic
Carboxylic Acid Group (COOH) – Acidic
The center asymmetrical carbon is called the alpha carbon.
The R group (think random) is variable for each amino acid! Also called the side chain.

37. Four Levels of Protein Structure
Primary structure of a protein is its unique sequence of amino acids.
Secondary structure, found in most proteins, consists of coils and folds in the polypeptide chain. The sequence of amino acids converts into 1 of 2 forms
α-helix
β-pleated sheets

38. 1’ and 2’ Levels Protein Structure

39. Tertiary structure is determined by interactions among various side chains (R groups)
Quaternary structure results when a protein consists of multiple polypeptide chains
Not found in all proteins
Same bonds/interactions as tertiary level

40. Tertiary & Quaternary Levels

42. Protein Denaturation

43. Protein Denaturation Denaturation Structure & Function
Protein unravels and loses its native conformation
Structure & Function
Change in the protein’s structure = loss of function
Denaturation occurs:
Organic solvent
Any chemical that disrupts the tertiary structure
Heat (excessive)

45. R E V I W

46. Macromolecules Macromolecule Function Structure Carbohydrate Lipid
Nucleic Acids
Proteins

47. Sample MC Which molecule stores the largest amount of energy? A. Fat
B. Starch
C. Protein
D. Glycogen

48. Sample Question
A molecule with the chemical formula C16H32O16 is probably a
A) carbohydrate.
B) lipid.
C) protein.
D) nucleic acid.
E) hydrocarbon.

49. Sample MC Amino acids are the building blocks of Proteins Lipids
Carbohydrates
Nucleic Acids

50. Sample MC Which polymer carries genetic information? Protein Lipid
Carbohydrate
Nucleic Acid

51. Sample MC Unlike carbohydrates and fats, proteins contain _____.
A) nitrogen
B) carbon
C) hydrogen
D) oxygen

52. Sample MC
. Which of these elements is NOT part of a carbohydrate molecule?
A) hydrogen
B) oxygen
C) carbon
D) magnesium