1. Section 6.3 – Life Substancesp

2. Role of Carbon in Organisms
Carbon (C) has 4 electrons available for bonding
C bonds to form single, double, or triple bonds with other atoms

3. Role of Carbon in Organisms
When C-C atoms, can form straight or branched chains, or rings

4. Role of Carbon in Organisms
Isomer
Compounds that have the chemical formula but different 3-D structures
Examples:
C6H12O6
Glucose, Fructose, Galactose

5. Role of Carbon in Organisms
Biomolecules
Large organic compounds
May consist of 100s or 1000s of C atoms
Example:
Protein

6. Role of Carbon in Organisms
Polymer
Large molecule formed when many smaller molecules bond together
Condensation Reaction
monomer + monomer = polymer + H2O
Hydrolysis
polymer + H2O = monomer + monomer

7. Condensation
Hydrolysis

8. Carbohydrates Used to provide cells with energy
Biomolecule composed of Carbon, Hydrogen, + Oxygen
Found in ratios of 2 H: 1O; the # of C atoms varies

9. Carbohydrates Monosaccharides A building block of a carbohydrate
A simple sugar
Most common types:
Glucose – used in cells
Fructose – found in fruits
Galactose – found in milk

10. Carbohydrates Disaccharide “double sugar”
Combination of 2 monosaccharides from a condensation reaction
Example:
Sucrose

11. Carbohydrates Polysaccharides Composed of many monosaccharides
Examples:
Starch
Stored as branched chain of glucose
Used as energy storage for plant cells
Glycogen
Stored as highly branched chain of glucose
Used as energy storage for animal cells
Cellulose
Stored as chain-linked branches of glucose
Makes up plant cell walls

12. Polysaccharides Examples

13. Lipids Biomolecule composed of C, H, + few O Examples: Fats Oils Waxes
Steroids

14. Lipids Lipids are insoluble in water because molecules are nonpolar
Not attracted by water

15. Lipids Fatty Acid Long chain of carbon + hydrogen
Building block of lipids
Saturated
C-C (single bonds)
Unsaturated
C-C (double bond)
Polyunsaturated
C-C (many double bonds)

16. Lipids Functions of lipids: Energy storage Insulation
Protective coverings
Cell membrane

17. Proteins
Functions:
Provide structure for tissues + organs
Carries out cell metabolism
Large, complex polymer composed of C, H, O, Nitrogen (N), + Sulfur (S)

18. Proteins Amino Acid (AAs) A building block of proteins 20 common AAs
Linked by condensation reaction – forms a peptide bond

20. Proteins Proteins come in a large variety of shapes + sizes
The number + sequence of AAs determines its shape

21. Proteins Enzyme Protein that changes the rate of the chemical reaction
May increase or decrease activity
Activity of enzyme depends upon:
Temperature
Ionic conditions pH
Works like a “lock + key”
Example (p. 162)

22. Nucleic Acids Are necessary for life
Complex biomolecule that stores cellular information in the form of a code

23. Nucleic Acids Nucleotide A building block of nucleic acids
Composed of C, H, O, N, + Phosphorus (P)
Arranged in 3 groups:
Nitrogenous base
Simple sugar
Phosphate group

24. Nucleic Acids Types of Nucleic Acids DNA RNA Deoxyribonucleic acid
Master copy of organism’s information (appearance + behavior)
Contains the instructions to be used by cell
Passed down as cell divides
RNA
Ribonucleic acid
Formed from DNA to make proteins