1. The Chemical Building Blocks of Life
Biomolecules
The Chemical Building Blocks of Life

2. The Chemistry of Carbon
Organic molecules contain carbon
Carbon’s four valence electrons allow it to form up to four covalent bonds
Hydrocarbons consist only of C and H
Propane CH8
It can easily bond to itself and form long chains
Linear - Cyclic - Branched

3. Functional Groups
Chemical properties and reactivity are a result of functional groups
Functional groups maintain chemical properties no matter where they occur
Polar molecules are hydrophilic
Nonpolar molecules are hydrophobic
The degree to which organic molecules interact with water affects their function
Hydroxyl group (-OH) is one of the most common functional groups, it will make a molecule water soluble

4. The Molecular Logic of Life
Small molecules, common to all organisms, are arranged into unique macromolecules (Campbell p. 62)

5. Macromolecules – The Sum of the Parts
Many complex biological activities require large macromolecules
Macromolecules are polymers
poly: “many”
mer: “units”
ex: proteins, nucleic acids, starches

6. Polymers are built by covalently linking together small similar (or in some cases, identical) subunits/building blocks called monomers mono: “one” mer: “unit” ex: amino acids, nucleotides, monosaccharides

7. 4 Classes of Organic Compounds, or “Biomolecules”- necessary for an organism to survive: Proteins are polymers of amino acids Nucleic acids are polymers of nucleotides Starches are polymers of simple sugars called monosaccharides Lipids aren’t REALLY polymers, since they don’t have repeating chains. BUT they are important biomolecules. The building blocks (monomers) of some types of lipids are glycerol and fatty acids

8. Condensation It’s not just for the water cycle anymore
Condensation It’s not just for the water cycle anymore! This is how we link monomers together to create polymers
Macromolecules are constructed by covalently bonding monomers by condensation reactions where water is removed from the functional groups of the monomers
Dehydration synthesis (water is removed)
A hydroxyl (-OH) from one monomer and a hydrogen (-H) from another are removed
Anabolic reaction- requires energy

9. Hydrolysis Hydrolysis is the reverse of condensation
Results in the break down of polymers
Hydration reactions add water and break bonds, releasing energy-- catabolic
animation

10. Macromolecules- why are they so important?
Each macromolecule performs complex tasks with precision
The basic structure and function of each class of macromolecules is similar in all organisms (from the simplest bacteria to complex humans)– indicates an evolutionary link.

11. Classes of Biomolecules
Carbohydrates
Lipids
Proteins
Nucleic Acids

12. Basic Function Carbo’s Lipids N. Acids Proteins Energy Storage
Structure
Strength
Long term storage
Insulation
Protection
Hormones
Inheritance
Blueprint for metabolism
Catalysts
Defense
Sugars (glucose)
Starch/
Glycogen
Cellulose/
Chitin
Fats
Oils/Waxes
Phospholipids
Steroid hormones
DNA
RNA
ATP
Enzymes

13. Carbohydrates How Sweet It Is!
General formula (CH2O)n
Simple sugars or large molecules made of sugar monomers
Monosaccharides (monomer) are covalently linked by condensation reaction to form polysaccharides (polymers)

14. Sugars Monosaccharides Five carbon: Ribose
Six carbon: glucose and fructose
Disaccharides
Sucrose
Lactose
Polysaccharides
Starch
Glycogen
Chitin
Cellulose

15. Polysaccharides Two Types for Storage
1. Glycogen – animal energy storage product that accumulates in the liver/muscles
- Highly branched
GlucoseGlycogenglucosebloodstream
2. Starch – plant energy storage
- Helical
- Easily digested by animals through hydrolysis

16. Two Types for Structure:
Cellulose
Polysaccharide found in plant cell walls
For humans cellulose is indigestible and forms dietary fiber
Made up entirely of β glucoses
Structure is constrained into straight microfibrils
Not an energy source for animals
2. Chitin – insect exoskeletons

17. So what’s the difference between condensation and hydration reactions?
animation

18. Lipids Functions: Long-term energy storage/insulation (fats)
Structural components of cells (phospholipids)
Cellular messengers (hormones)

19. More FAT
Triglycerides are composed of three fatty acids covalently bonded to one glycerol molecule
Fatty acids are composed of CH2 units and are hydrophobic- contain tons of energy in their hydrocarbons!
Fatty acids can be saturated (all single bonds) or unsaturated (one or more double bonds)
A fat (mostly saturated) is solid at room temp., while an oil (mostly unsaturated) is liquid at room temp.

20. video
Glycerol is a molecule with three carbons in a row, each with a hydroxide group
Fatty acid chains are hydrocarbons
that is, they are composed of mostly carbons and hydrogens.
This is a molecule that is VERY hydrophobic.
When glycerol combines with the fatty acid chains it forms a carboxyl group between them
They link by the loss of a water molecule.
Carbon can bond to four different substances, but sometimes it will share more than one pair of electrons.
animation

21. Phospholipids Important structural component of cell membranes
Phosphate group (head) is polar and water soluble (hydrophilic)
Two fatty acid tails are hydrophobic
This allows the phospholipids to
form bilayers and membranes

22. Other Lipids Steroids Cholesterol Hormones Waxes Insoluble in water
Built around a four ringed skeleton
Cholesterol
Component for animal cell membranes
Formation of myelin sheath covering nerves
Hormones
Chemical messengers
Waxes
Many fatty acids linked to a long backbone
Waterproofing in plants, ears, beehives
overview

23. Proteins 50% dry weight of body Mammal cell contains 10,000 proteins
Enzymes (regulate chemical reactions)
Structural elements (cell membrane, muscles, ligaments, hair, fingernails)
Carriers (regulate what goes into/out of cells)
Send and receive messages (hormones)
Movement

24. Building Blocks of Proteins Amino Acids
Amino acids (monomers) are linked together to form proteins (polymers)
Each unique sequence of amino acids forms a different protein
All living things (even viruses) use the same 20 amino acids
20 different Amino Acids
Amino end (NH2)
Carboxyl end (COOH)
Hydrogen
R group – variable component

25. Amino Acids Positively charged side chain
Amino Acids are grouped by whether R- group is polar or non-polar
Positively charged side chain
Negatively charged side chains
Polar but uncharged side chains
Hydrophobic side chains
Special cases

26. Protein Assembly
AA’s are linked together by joining the amino end of one molecule to the carboxyl end of another
Peptide bond forms a chain called a polypeptide

27. Protein Structure Primary structure
Specific linear sequence of AA’s in a polypeptide
Determined from code in inherited genetic material
Changes in primary structure can alter proper functioning of the protein

28. Hormone: Insulin
Frederick Sanger (1940s, 50s), discovered the amino acid sequence of Insulin
Causes cells to take up more glucose, and liver and muscle cells to create glycogen
Diabetes is a deficiency of insulin

29. Carrier: Hemoglobin -Protein that carries oxygen to your cells
-Iron an important co-factor, iron deficiency =anemia

30. Sickle Cell Disease

31. Spider silk: a structural protein
Spider Silk Video

32. Enzyme: Salivary Amylase
Hydrolyzes starch while chewing

33. Enzyme: Rubisco
Catalyzes first step of carbon fixation in photosynthesis

34. Movement: Actin and Myosin

35. Secondary structure
the tendency of the polypeptide to coil or pleat due to H-bonding between R- groups
-helix, -pleated sheet, or random coil

36. Tertiary structure shape of entire chain; folded, twisted, or globular
shape related to function and properties

37. Quaternary structure
more than one polypeptide chain

38. Nucleic Acids Polymers composed of monomer units known as nucleotides
Information storage
DNA (deoxyribonucleic acid)
Protein synthesis
RNA (ribonucleic acid)
Energy transfers
ATP (adenosine tri-phosphate) and NAD (nicotinamide adenine dinucleotide)

39. Nucleotides Structure Phosphate Nitrogenous base
Purines (double-rings)
Adenine and Guanine
Pyrimidines (single-rings)
Cytosine, Thymine, and Uracil
Sugar – either ribose or deoxyribose
pentoses in ring form
Deoxyribose lacks one oxygen

40. Functions of Nucleic Acids
DNA – Physical carrier of genetic information
Restricted to nucleus
RNA – key component of protein synthesis
Messenger RNA (mRNA) – blueprint for construction of a protein
Ribosomal RNA (rRNA) – construction site where the protein is made
Transfer RNA (tRNA) – truck delivering the proper AA to the site of construction

41. The End