2. Macromolecules: Superstructures of Life
Biochemistry- study of the compounds of life
Biochemicals- organic compounds produced by (or components of) living things
Four main families- carbohydrates, lipids, proteins, and nucleic acids
Often very large, called macromolecules
All macromolecules except for lipids are formed by polymerization
Repeating subunits (monomers) are bound in to chains of various lengths (polymers)

3. Carbohydrates Carbohydrates: Sugars and Polysaccharides
Most can be represented by the general formula (CH2O)n, where n = the number of units of this combination of atoms

4. Carbohydrates Exist in a variety of configurations
Sugar (saccharide)- a simple carbohydrate with a sweet taste
Monosaccharide contains 3-7 carbons
Disaccharide contains two monosaccharides
Polysaccharide contains five or more monosaccharides
Monosaccharides and disaccharides are specified by combining a prefix that describes a characteristic of the sugar with the suffix –ose
Hexoses- six carbons
Pentoses- five carbons
Fructose- for fruit

5. Figure 2.14

6. The Nature of Carbohydrate Bonds
Figure 2.15

7. The Functions of Polysacharides
Structural support and protection
Serve as nutrient and energy stores
Cell walls in plants and many microscopic algae from cellulose
Figure 2.16a

8. Other Important Polysaccharides
Include agar, peptidoglycan, chitin, lipopolysaccharide, glycocalyx, and glycogen
Figure 2.16b

9. Lipids: Fats, Phospholipids, and Waxes
Lipids- a variety of substances that are not soluble in polar substances
Will dissolve in nonpolar solvents
Main groups of lipids
Triglycerides-a single molecule of glycerol bound to three fatty acids
Includes fats and oils

10. Figure 2.17

11. Phospholipids
Phospholipids- Contain two fatty acids attached to the glycerol with a phosphate group on the third glycerol binding site
Important membrane molecules
Figure 2.18

12. Miscellaneous Lipids
Steroids- complex ringed compounds commonly found in cell membranes and animal hormones
Best known- cholesterol
Waxes- esters formed between a long-chain alcohol and a saturated fatty acid

13. Figure 2.19

14. Proteins: Shapers of Life
Predominant organic molecules
Building blocks- amino acids
20 different naturally occurring forms
Basic skeleton- a carbon (the α carbon) linked to an amino group (NH2), a carboxyl group (COOH), a hydrogen atom (H), and a variable R group
Peptide bond forms between the amino group on one amino acid and the carboxyl group on another.

16. Figure 2.20

17. Protein Structure and Diversity
Primary (1°) structure- the type, number, and order of amino acids in the chain
Secondary (2°) structure- when various functional groups exposed on the outer surface of the molecule interact by forming hydrogen bonds
Coiled configuration- α helix
Accordion pattern- β-pleated sheet
Tertiary (3°) structure- created by additional bonds between functional groups
Quarternary (4°) structure- more than one polypeptide forms a large, multiunit protein

18. Figure 2.21

19. Protein Shape
Each different type of protein develops a unique shape, so it can only react with molecules that fit its particular surface features
Ex. enzymes and antibodies
Native state- the functional three-dimensional form of a protein
Denatured- when the protein’s native state has been disrupted

20. The Nucleic Acids: A Cell Computer and Its Programs
DNA- specially coded genetic program
DNA transfers its program to RNA
Both are polymers of repeating units called nucleotides
Nucleotides- composed of three smaller units: a nitrogen base, a pentose sugar, and a phosphate.
The nitrogen base can be one of two forms- a purine (two rings) or a pyrimidine (one ring)
Two types of purines: adenine (A) and guanine (G)
Three types of pyrimidines: thymine (T), cytosine (C), and uracil (U)
DNA contains all of the nitrogen bases except uracil
RNA contains all of the nitrogen bases except thymine
The nitrogen base is covalently bonded to ribose in RNA and deoxyribose in DNA
Phosphate (PO43-) covalently bonds the sugars in series

21. Figure 2.22

22. Figure 2.23

23. The Double Helix of DNA Formed by two long polynucleotide strands
Linked along their length by hydrogen bonds between complimentary pairs of nitrogen bases
Adenine pairs with thymine
Cytosine pairs with guanine

24. RNA: Organizers of Protein Synthesis
Also consists of a long chain of nucleotides
It is single stranded and contains ribose instead of deoxyribose anduracil instead of thymine
Several functional types of RNA formed using the DNA template
Messenger RNA (mRNA)- a copy of a gene that provides the order and type of amino acids in a protein
Transfer RNA (tRNA)- a carrier that delivers the correct amino acids for protein assembly
Ribosomal RNA (rRNA)- a major component of ribosomes

25. The Energy Molecule of Cells
Adenosine triphosphate (ATP)- a nucleotide containing adenine, ribose, and three phosphates
High-energy compound that gives off energy when the bond is broken between the outermost phosphates
Releases and stores energy for cellular chemical reactions
When the terminal phosphate bond is broken to release energy, adenosine diphosphate (ADP) is formed
ADP can be converted back to ATP when the third phosphate is restored.

26. Figure 2.25