1. Building Complex Molecules That Comprise Living Things
Macromolecules
Building Complex Molecules That Comprise Living Things

2. Four types of organic macromolecules are important in living systems.
Comparison of Terms
Molecule
Two or more atoms joined by chemical bonds
Macromolecule
Large polymer made of repeating monomer units
Four types of organic macromolecules are important in living systems.

3. Macromolecules: Polymers Made of Repeating Monomers
Monomer Unit
Carbohydrates
Sugars
Lipids
Fatty acids
Proteins
Amino acids
Nucleic Acids
Nucleotides

4. Organic Macromolecules Contain Carbon
Question: How many electrons does carbon need to fill its outer energy level?
Answer: Four
Each carbon atom can make four
covalent bonds with other types of
atoms or additional carbons.

5. Carbon atoms can be joined by single, double or triple bonds.
double bond
Carbon atoms can be joined by single, double or triple bonds.

6. Synthesis and Breakdown of Macromolecules
Dehydration Synthesis
Removal of water to add monomer units
Hydrolysis
Addition of OH and H groups of water to break a bond between monomers

7. Dehydration Synthesis / Hydrolysis

8. Carbohydrates: Structure
Simple
Monosaccharides= one sugar unit
Glucose = blood sugar
All cells use glucose for energy

9. Chemical Formula for a Six-Carbon Sugar

10. Carbohydrates: Structure
Simple
Disaccharides = two sugar units
Oligosaccharides (“oligo-” means few or scant).
Several monosaccharides joined together.
Sucrose (table sugar) is disaccharide of one glucose and one fructose (Fig 3-1, p39).
Often combined with other molecules.
Many larger molecules have oligosaccharides attached for various purposes.
Sometimes used for cell ID.
The cell membrane has many proteins in it, some of which have attached oligosaccharides projecting away from the cell. Sometimes these are used as chemical labels for cell type.
CH2OH H HO OH O
Glucose
CH2OH H HO OH O
HOCH2 O
HOCH2 H
CH2OH HO
Fructose + HO H
Sucrose & Water

11. Carbohydrates: Structure
Simple
Disaccharides = two sugar units
Sucrose = glucose + fructose table sugar
Lactose = glucose + galactose milk sugar
Maltose = glucose + glucose seed sugar

12. Carbohydrates: Structure
Complex
Polysaccharides= many sugar units
Starch -- storage in plants
Glycogen -- storage in animals
Cellulose -- plant cell walls, indigestible (fiber)

13. Carbohydrates: Functions
Energy source
Structural component
Cell-cell communication

14. Mac ‘n Cheese Nutrition Label
Nutrition Facts
Serving Size 1 cup (228g)
Servings Per Container 2
Start here
Amount Per Serving
Calories 250
Calories from Fat 110
% Daily Value
Total Fat 12g
18%
Saturated Fat 3g
15%
Limit these
nutrients
Trans Fat 1.5g
Cholesterol 30mg
10%
Sodium 470mg
20%
Total Carbohydrate 31g
10%
Dietary Fiber 0g 0%
Sugars 5g
Get enough
of these
nutrients
Protein 5g
Vitamin A 4%
Vitamin C 2%
Calcium
20%
Iron 4%

15. Applying Your Knowledge
Monosaccharide
Polysaccharide
Disaccharide
Which molecule consists of two sugar units?
Which choice best describes glycogen?
Which type of molecule provides the basic energy for your cells?
Which type of molecule is found in milk?

16. Lipids: Structure Triglyceride—predominant form in diet
One molecule of glycerol
Three fatty acids

17. Lipids: Structure Types of Fatty Acids
Saturated – 2H per internal carbon
Unsaturated -- <2H per internal carbon one or more double bonds
Monounsaturated – one double bond
Polyunsaturated – more than one double bond

18. Triglyceride FormationH C OH O C H
Glycerol
Remove These Waters C O H
This shows how water is removed from three fatty acids and glycerol to make a fat and water. C OH O H C OH O H C OH O H C O H
Add 3 Fatty Acids
HOH
3 Waters

19. Physical dispersion of lipids
Emulsification
Physical dispersion of lipids
Mixing with a molecule having a polar and non-polar end
Bile from gall bladder emulsifies fats prior to digestion

20. Lipids: Structure Phospholipid—component of cell membranes Hydrophilic
Polar Head
Glycerol
Fatty Acid Tails
Hydrophilic
Hydrophobic

21. Lipids: Structure Steroids Linked carbon rings Natural body components
Hormones
Cholesterol
Complex ring forms
Some hormones, especially those produced by the adrenal gland and sex hormones.
Cholesterol
Natural substance; not necessarily bad for you.
Found in membranes in between the fatty acid tails of phospholipids.
Athletes beware of androgenics!
Dangerous chemicals.
Please reconsider your value system if you use these.
If you use them, you WILL regret it!

22. Steroids
Cholesterol
Estradiol
Testosterone

23. Lipids: Functions Concentrated energy source
Structural components of cell membranes
Phospholipids
Cholesterol
Communication
Steroid Hormones
Protection from water
Waxes
Cholesterol
Phospholipids

24. Mac ‘n Cheese Nutrition Label
Nutrition Facts
Serving Size 1 cup (228g)
Servings Per Container 2
Start here
Amount Per Serving
Calories 250
Calories from Fat 110
% Daily Value
Total Fat 12g
18%
Saturated Fat 3g
15%
Limit these
nutrients
Trans Fat 1.5g
Cholesterol 30mg
10%
Sodium 470mg
20%
Total Carbohydrate 31g
10%
Dietary Fiber 0g 0%
Sugars 5g
Get enough
of these
nutrients
Protein 5g
Vitamin A 4%
Vitamin C 2%
Calcium
20%
Iron 4%

25. Applying Your Knowledge
Polyunsaturated fatty acid
Cholesterol
Monounsaturated fatty acid
Saturated fatty acid
Which molecule is made of a series of carbon rings?
Which molecule has more than one double bond?
Which molecule has 2H for each internal carbon?
Which molecule has one double bond?

26. The “R” Group Differs for Each Amino Acid
Proteins: Structure
Primary structure = chain of amino acids
Amino acids have common features
Carboxylic Acid Group
Amino Group    
See p 34 R
Central Carbon
The “R” Group Differs for Each Amino Acid

27. Proteins: Structure Forming the Protein Chain
Phenylalanine
Leucine
Here we position two amino acids close together so that the amine group of one is close to the carboxyl group of the other.
Note that a -H is hanging out from one, and a -OH from the other.
These will be broken off (by an enzyme) to form water.
The remaining bonds of the two amino acids will be connected to form a dipeptide (two amino acids joined by a peptide linkage).
Dehydration Synthesis between COOH & NH2

28. Proteins: Structure Forming the Protein Chain
The Peptide Bond
Water
Phenylalanine-Leucine Dipeptide

29. Four Levels of Protein Structure
Primary (Sequence)
Tertiary (Folding by R-group interactions)
Depending on the sequence of amino acids, the polypeptide chain can either form a spiral like the tube on the left, or a pleated sheet like on the right.
Some proteins have a spiral section followed by a sheet section, etc.
Fig 2.26, p35.
Quaternary (Two or more chains associating)
Secondary (Coiling by Hydrogen Bonding)

30. Four Levels of Protein Structure
Primary Structure = sequence of amino acids in chain

31. Four Levels of Protein Structure
Secondary Structure
Folded structure due to hydrogen bonds between the amino and acid groups of amino acids N C N C H O H or O O H O H C N C N

32. Found in most proteins
Found in silk

33. Four Levels of Protein Structure
Tertiary Structure:
Three dimensional folded structure due to attractions and repulsions between R groups
Can involve
covalent bonding hydrogen bonding ionic interactions hydrophilic and hydrophobic interactions

35. Hair Curling Straight Hair Naturally Curly Hair | S | S | | S | S |

36. Four Levels of Protein Structure
Quaternary Structure:
Association of two or more protein chains
eg. Hemoglobin is composed of 4 protein chains
2 are called alpha hemoglobin
2 are called beta hemoglobin

37. Denaturation of Proteins
Disruption of secondary, tertiary or quaternary protein structure
Caused by heat or changes in pH
Irreversible, causes loss of protein function
protein unfolds

38. Proteins: Functions Structural Component of Cells
Control of Metabolic Reactions: enzymes
Maintain homeostasis
Transport substances in blood
Antibodies protect against invaders
Growth and Repair
Support and Motion
Communication
Protein Hormones
Cell Receptors
Energy source
Protein
Protein

39. Applying Your Knowledge
Primary
Secondary
Tertiary
Quaternary
Which structure results from hydrogen bonding?
Which structure involves an association of two or more protein chains?
Which structure describes the linear sequence of amino acids?
Which structure depends upon interactions between the R groups of the amino acids?