Topic 2 Chemical Basis of Life

Atom- smallest stable unit of matter Elements… Atom- smallest stable unit of matter 2.1.1

Atomic #... Atomic weight…

Isotopes Atoms with same atomic number, but different atomic weights. 2.2.2

Molecule of an element Molecule of a compound Compounds & molecules 2.1.3

Bonding of atoms 2.3(3,4)

Ionic bond 2.4.1

Covalent bond

2.4.6

Hydrogen bonds 2.5.5

Chemical reactions Synthesis Decomposition Exchange 2.8

Acids, bases, & salts Electrolytes pH = [H+] or [OH-]

2.12.2

Chemical constituents of cells 2.9.3

1. Water: Most abundant in living material. Universal solvent & medium Transport for material High heat capacity & vaporization 2.11(1-3)

2. Oxygen (O2): 3. Carbon dioxide (CO2): For cellular respiration C6H12O6 + O2  CO2 + H2O 3. Carbon dioxide (CO2): Waste Forms weak acid in blood Then dissociates Can be a buffer in blood

4. Inorganic salts: Electrolytes dissociate to form ions Importance… Water concentration pH balance blood clotting Bone development Energy transfer Muscle/nerve function

Organic molecules Carbohydrates Lipids Proteins Nucleic acids “Polymers of monomers”

Carbohydrates Purpose: Main energy source Raw material Short-term energy storage Naming… Classification… 2.14.1

Simple sugars 2.14

2.14(3,4)

Complex sugars 2.14.5

Long-term energy storage Membrane structure Characteristics… Elements… Lipids Purpose: Long-term energy storage Membrane structure Characteristics… Elements… Hydrophobic Fatty acids… 2.15(1,3)

2.11.6

Uses: Energy Storage Insulation Protection Fats vs oils Triglycerides 2.15.4

Phospholipids & glycolipids Uses: Cell membranes 2.16.3

Cholesterol & Steroids

Synthesized by the liver Uses: Strengthens cell membranes Starts as cholesterol Synthesized by the liver Uses: Strengthens cell membranes Gets converted to steroids Estrogen Testosterone Aldosterone 2.16.2

Structural building blocks Enzyme/hormones Energy source Proteins Purpose: Structural building blocks Enzyme/hormones Energy source Characteristics: Elements… Amino acids… Shape… 2.17.1

Peptide bonds 2.17.2

2.17.4

Denaturation Conformation change Shape is… Function is … Denaturing agents: Heat Radiation pH extremes chemicals

Stores genetic information Control protein synthesis Nucleic acids Purpose: Stores genetic information Control protein synthesis Regulates cellular activity Characteristics: Elements… Nucleotides… Genetic code… 2.20.1

2.20.2

DNA Sugar

Nitrogen Bases 2.20.1

Hydrogen bonds

Complimentary pairing 2.20.3

RNA

RNA sugar

Works with genetic material to create… 3 kinds: RNA bases Made from… Single strand Works with genetic material to create… 3 kinds: mRNA tRNA rRNA 2.20.4