BIOL 1001 Chapter : Chapter 2 Atoms Molecules And Life Part 2 Of 2
Document Summary
Water makes up 60-90% body weight of most organisms. 2. 8: cohesion of water molecules along a surface produces surface. Tension: spiders and water striders rely on surface tension to move across the surface of ponds (l- below) Water molecules stick to polar or charged surfaces according to the property called adhesion: adhesion helps water climb up the thin tubes of plants to the leaves. Water-soluble molecules are hydrophilic: ex. - sugars and amino acids. Sugars and amino acids: water-based solutions can be acidic, basic , or neutral. A small fraction of water molecules break apart into ions (fig. Solutions where h+ > oh are acidic: for example, hydrochloric acid ionizes in water: Hcl h+ + cl : lemon juice and vinegar are naturally occurring acids. Solutions where oh > h+ are basic: for example, sodium hydroxide ionizes in water: A base is a substance that combines with hydrogen ions (reducing.
