Condensed Bio 12 Notes - Biological Molecules

Bio 12 notes
Subject Biological Molecules




#1: Water
●​ Polarity

○​ Oxygen end is slightly negative

○​ Hydrogen end is slightly positive

↳ makes water a great solvent + act like a tiny magnet

○​ Water molecule -> shaped like a V

●​ Cohesion

○​ Water molecules stick to each other

●​ Adhesion

○​ Water molecules stick to other surfaces

↳ drives transport in living things

, ●​ Universal solvent

○​ Dissolves ions and polar molecules, enabling chemical reactions inside cells

●​ High specific heat

○​ absorbs/releases a lot of heat before changing temperature

↳ helps stabilize body temperature

●​ Charge attraction

○​ Negative side of water -> attract positively charged particle

■​ Sodium in salt

○​ Positive side of water -> attract negatively charged particle

■​ Chloride

↳ attraction pulls apart molecule -> dissolves it

●​ Hydrogen bonding

○​ Water molecules form temporary bonds easily -> help disperse + stabilize
dissolved particles through solution




#2: Acids + Bases + pH Scale
●​ Acid

○​ A substance that donates H+ ions in water (lower pH in scale)

●​ Base

○​ A substance that accepts H+ ions/donates OH- (higher pH in scale)



stomach black baking
acid coffee water soda ammonia
1 2 3 4 5 6 7 8 9 10 11 12 13 14


●​ Enzymes, proteins, and cell processes work within certain pH range