1. Biological Macromolecules
Year 11 Biology Unit 1

2. Four Major Types of Biological Macromolecules
Type of Polymer
Monomers making up Polymer
Example
I. Carbohydrates (Polysaccharides)
Monosaccharides
Sugars, Starch, Cellulose
II. Lipids
Fatty acids and glycerol
Fats, steroids, cholesterol
III. Proteins
Amino acids
Enzymes, structural components
IV. Nucleic Acids
Nucleotides
DNA, RNA

3. I. Carbohydrates Short term energy
Made from monomers called monosaccharides (simple sugars)
Short term energy
Glucose: most common, used directly in cellular respiration to make ATP (energy)

4. Figure 5.3 The structure and classification of some monosaccharides

5. Disaccharides

6. Polysaccharides: Complex Carbohydrates
3 major types made from monomers of glucose:
Starch: energy storage in plants
Glycogen: energy storage in animals
Cellulose: structural molecules in plants

7. Figure 5.6 Storage polysaccharides

8. Figure 5.7a Starch and cellulose structures

9. Figure 5.7b,c Starch and cellulose structures

10. Figure 5.8 The arrangement of cellulose in plant cell walls

11. II. Lipids Not true polymers
Composed of mostly glycerol and fatty acids
Includes
Fats: energy storage
Phospholipids: membranes
Steroids: hormones, cholesterol

12. Fats are made of one glycerol and three fatty acids

13. Double bonds, fewer H atoms No Double bonds, maximum H atoms
Double bonds between carbons cause
kinks in hydrocarbons.
H2C
CH2
H2C
CH2
H2C CH
Kink CH
H2C
Figure: 4.8b
Caption:
(b) The double bond(s) found in an unsaturated hydrocarbon produce a “kink” (shown exaggerated) in an otherwise straight chain. The icon on the right indicates that one of the hydrocarbon tails in a phospholipid is unsaturated. Exercise Draw figures analogous to those in part (b) for a hydrocarbon chain containing two double bonds. (Hydrocarbon chains like these are called polyunsaturates because poly means “many.”)
CH2
H2C
Unsaturated
fatty acid
Saturated
fatty acid
CH2
H2C
Double bonds, fewer H atoms
No Double bonds, maximum H atoms

14. Figure 5.11 Examples of saturated and unsaturated fats and fatty acids

15. Phospholipids are made of one phosphate group and 2 fatty acids
Phospholipids are amphipathic

16. Figure 5.13 Two structures formed by self-assembly of phospholipids in aqueous environments   

17. Figure 5.14 Cholesterol, a steroid
Steroids consist of a complex carbon ring structure
Figure Cholesterol, a steroid    

18. Figure 4.8 A comparison of functional groups of female (estradiol) and male (testosterone) sex hormones

19. III. Proteins H2N C R H O OH Made from monomers called amino acids
Very different structures, very different functions
H2N
Amino
group C
Side chain R H O OH
Carboxyl

20. The R groups of an amino acid may be hydrophobic or hydrophilic

21. Amino acids are joined together by a dehydration reaction
H2N H C O OH
Carboxyl
group N
CH3
Peptide
bond
Amino
H2O +

22. Many amino acids joined together = Polypeptide chain
N-terminus
C-terminus H H O H H O H H O H H O H H O H H O H H O H H O H N C C N C C N C C N C C N C C N C C N C C N C C OH H
CH3
CH2
CH2
CH2 CH
CH2
CH2 OH C OH
H3C
CH3 SH O
Figure: 3.9b
Caption:
(b) Amino acids can be linked into long chains by peptide bonds.  OH

23. The sequence of amino acids in the polypeptide chain = the primary structure of a protein

24. Hydrogen bonds between amino acids leads to the secondary structure of a protein
Two common secondary structures are the -helix and -pleated sheet

25. Further folding of the polypeptide chain contributes to the tertiary structure of a protein

26. The joining of more than one polypeptide chain leads to the quaternary structure of proteins

27. Heat (energy) can break up the structure of a protein

28. Table 5.1 An Overview of Protein Functions

29. IV. Nucleic Acids
Nucleic acids (DNA and RNA) are made of monomers called nucleotides
Nitrogenous base
Nitrogenous base
Phosphate group
Phosphate group
Sugar
Sugar

30. Figure 5.29 The components of nucleic acids

31. Space-filling model of
Figure 3.17b 5´ 3´ 5´ 3´ 5´ 3´ T A T
DNA is a
double
helix. A G C G C C G C G T A A T T A A T C G C G G C G A T A T T A T A C G C G
Figure: 3.17b
Caption:
(b) Complementary base pairing twists DNA into a double helix. T A T A G C T A A T G C C G T A A T 5´ 3´ 5´ 3´ 5´ 3´
Cartoon of
base pairing
Cartoon of
double helix
Space-filling model of
double helix

32. Nucleic acids store the information to make proteins

33. Figure 5.30 The DNA double helix and its replication