Chemistry of Life Concept 2 Notes PDF

 Organization of Life matter= anything that has mass and occupies space – Composed of ____ The smallest part of an element (think PT) that still has the properties of that element 6 elements necessary for life = C, H, O, N, P, S cell...

 Organization of Life matter= anything that has mass and occupies space – Composed of ____ The smallest part of an element (think PT) that still has the properties of that element 6 elements necessary for life = C, H, O, N, P, S cell = most basic unit of life  Water water (H2O) = molecule made of 2 atoms of hydrogen covalently bonded to 1 atom of oxygen – Critical for all of life’s processes!! – Has special properties, mostly due to the fact that water is a polar molecule  Polar and Nonpolar Molecules polar molecule: nonpolar Molecule: Unequal distribution no separation of of charges charge, so no – One side is more positive or negative positive poles are formed. – One side is more – Does not dissolve in negative water – Dissolves in water – Ex: CO2, O2, lipids – Ex: Water  Properties of Water cohesion Adhesion High specific heat less dense as a solid Water is a terrific solvent  Cohesion (“co-” means “together”) The attraction between molecules of the same substance – Water sticking to water Tendency of molecules of the SAME “kind” to stick together Causes HIGH surface tension – Measure of how difficult it is to stretch or break the surface of a liquid/resist an external force  Adhesion adheasion = The type of attraction that happens between two different molecules – Glass, soil, plant tissue, cotton, etc. Forms stronger bonds than cohesion Example: – Meniscus forming on graduated cylinder – Capillary action, seen in plants, trees and with straws too!  High specific heat The temp of water does not change easily. – Water has to absorb more heat energy to increase overall temperature compared to other compounds This helps to regulate cell temperatures in organisms. – Its temperature does NOT fluctuate very much 🡪 allows life to live in Water – Buffers large fluctuations in temperature which keeps Earth’s climate moderate.  Less dense as a solid solid water (ice) is less dense than liquid water 🡪 it floats in liquid water – Since ice floats in water 🡪 Life can exist under frozen surfaces of lakes/polar seas  Water is a terrific solvent solution – uniform mixture of two or more substances (Lemonade) solute – what gets dissolved (Lemonade powder) solvent – does the dissolving (Water) Water’s polarity makes it really good at dissolving things, and thus it is considered the universal solvent – it dissolves more substances than any other liquid!  Hydrophilic and Hydrophobic Substances A hydrophilic substance – Has an affinity for water – Water “loving” – Usually dissolves easily in water – Example: salt and sugar A hydrophobic substance – Does not have an affinity for water – Water “fearing” – Does NOT dissolve in water – Example: oil