Bio Lecture ppt The Chemistry of Life: Biological Macromolecules

1. The Chemistry
of Life

2. Organic Molecules Generate Life’s
Form and Function
• Organic molecules
– Contain carbon and hydrogen
• 4 most abundant types
– Carbohydrates, lipids, proteins, and nucleic
acids
• Monomers link together to form polymers
– Link by dehydration synthesis
– Broken apart by hydrolysis

3. Functional Groups of Organic
Molecules

4. Group Example
Hydroxyl
Methanol
Carbonyl
Butanone
Carboxyl
Acetic acid
Functional Groups of Organic
Molecules
Group Example
Amino
Methylamine
Phosphate
Glyceraldehyde 3-phosphate

5. Type of Molecule Chemical Structure Functions
Carbohydrates
Simple Sugars Monosaccharides
Disaccharides
quick fuel for metabolism, being used both as
an energy source (glucose being the most
important in nature) and in biosynthesis
Complex Carbohydrates
(starch, cellulose, chitin)
Polysaccharides cellulose and chitin are structural
polysaccharides; others are used for energy
Lipids
Triglycerides (fats, oils) glycerol and three fatty
acids
enable the bidirectional transference of
adipose fat and blood glucose from the liver
Phospholipids glycerol, a diglyceride, a
phosphate group, and a
simple organic molecule
major component of all cell membranes as
they can form lipid bilayers
Sterols fused four-ring core
structure
important component of membrane lipids;
hormones
Waxes long chain fatty acids and
primary alcohols
provide waterproofing (are insoluble in water)
Proteins one or more long chains of
amino acid residues
assist in cell function
Nucleic Acids (DNA,
RNA)
polynucleotides—strands
composed of nucleotides
store and use genetic information
Macromolecules of Life

6. Carbohydrates
• Monosaccharides – simple sugars
– 5, 6 carbon atoms
– Glucose, fructose

7. Carbohydrates
• Disaccharides – 2 monosaccharides
joined by dehydration synthesis
– Lactose, maltose (sugar cane, sugar beets)
Fructose Sucrose

8. Oligosaccharides
• Intermediate length carbohydrates
– 3 – 100 monomers together
– Glycoproteins – used for immunity
• Blood types – protein on the surface of blood cell
for A, B, AB, O

9. Oligosaccharides
• Intermediate length carbohydrates
– 3 – 100 monomers together
– Glycoproteins – used for immunity
• Blood types – protein on the surface of blood cell
for A, B, AB, O

10. Complex Carbohydrates -
Polysaccharides
• Complex carbohydrates
– Polysaharides
– Cellulose, chitin, starch, glycogen

11. Lipids
• Lipids are hydrophobic and Energy-Rich
– Do not dissolve in water
– Not polymers – extremely diverse
– Triglycerides
• 3 fatty acids plus glycerol
– Saturated versus unsaturated

12. Function of Fats
• Fats protect , insulate and store energy
• When energy resources low, body will pull from
fat stores (i.e. fat pad behind the eye)

15. Lipids
• Lipids are hydrophobic and Energy-Rich
– Sterols
• 4 interconnected carbon rings
• Vitamin D, cortisone, cholesterol, testosterone,
estrogen
Cholesterol Testosterone

16. Lipids
• Lipids are
hydrophobic and
Energy-Rich
– Waxes
• Fatty acids combined
with alcohols
• Stiff, water-repellant
material
Honey encased in beeswax

17. Phospholipids
• Amphipathic molecules
– Polar head
– Nonpolar tails

18. Proteins
• Proteins – Carbohydrates with N atom
– Need them to carry out most chemical reactions
in the body
– Made of amino acids
• C atom + COOH, NH2, R-group (distinguishing
character)
• 20 types
• Combined into proteins by peptide bonds
– Polypeptide = chain of amino acids
– Protein = polypeptide shaped into protein shape
– Denaturation – Modifying the structure of a
protein changing/destroying its function
• pH, heat, salt

19. Proteins

20. Proteins
• Proteins Are Complex and Highly Versatile
– Protein folding
• Primary (1º) structure
• Secondary (2º) structure
• Tertiary (3º) structure
• Quaternary (4º) structure
– Genetic code specifies amino acid sequence

22. Proteins
• Denaturation: loss of function
– Function depends on overall shape
– Vulnerable to conditions that alter shape
• Heat, salt, pH

23. Nucleic Acids
• Nucleic Acids Store and Transmit Genetic
Information
– Nucleic acid (polymer)
• DNA – stores genetic information
• RNA – enables cells to use DNA
– Nucleotide (monomer)
• Nitrogenous base – A, G, T, C, or U

25. DNA