Cells Fundamentals Properties of Water Biomolecules Properties of Water *The Importance of Water to Organisms High Water Content in living things Abiotic Factor Biodiversity Solvent Properties Next few slidesfor discussion of these topics ALL Based on the Properties of Water: The Water Lab *Know these topics IN GENERAL, you DO NOT have to memorize specific numbers/% given Humans Up to 60% of the human body is water, (The brain is composed of 70% water, and the lungs are nearly 90% water. Lean muscle tissue contains about 75% water by weight, as is the brain; body fat contains 10% water and bone has 22% water. About 83% of our blood is water, which helps digest our food, transport waste, and control body temperature.) Each day humans must replace 2.4 liters of water, some through drinking and the rest taken by the body from the foods eaten. Water as an Abiotic Factor: its everywhere! Water is the key to our survival on Earth, it is our source of life Water is everywhere! It makes up about 70% percent of the Earths surface Of that water, about 97% is ocean, and only 3% is fresh water Water and Biodiversity The Universal Solvent Water is capable of dissolving a variety of different substances, which is why it is such a good solvent. In fact, water is called the "universal solvent" because it dissolves more substances than any other liquid. This is important to every living thing on earth. It means that wherever water goes, either through the air, the ground, or through our bodies, it takes along valuable chemicals, minerals, and nutrients. *Properties of Water Cohesion Adhesion Surface Tension Capillarity Discuss each/relate to Water Lab Definitions Cohesion: Molecules have a strong tendency to stick to one another. -Attraction between like substances -Water is attracted to Water: spherical shape of the mid air droplet/dome shape on the penny/in the petri dish Adhesion: Molecules have the ability to stick (adhere) to one another. -Attraction between like substances -Water sticks to other substances: teardrop shape at the tip of the pipette/penny/sides of the petri dish/sides of the capillary tubes Adhesion and Cohesion AdhesionCohesion .and gravity Surface Tension The property of the surface of a liquid (water) that allows it to resist an external force, (adhesion) due to the cohesive nature of the (water) molecules. *Stronger cohesive forces between surface water molecules (and pull downward from those below) than adhesive forces of attraction to the air, creating a supportive skin. *Needle is MORE DENSE than the water- should NOT float Capillary Action The movement of water (in a tube) due to the forces of adhesion, cohesion, and surface tension. *When the adhesion to the walls is stronger than the cohesive forces between the liquid molecules; limited by surface tension and gravity. Importance in Biology ? Plants take advantage of capillary action to pull water from the into themselves. From the roots water is drawn through the plant by another force, transpiration. Which is greaterA or C? ? Surface Tension and Capillary Action Hydrogen Bonding explains the way water responds to changes in temperature Hydrogen bonds are formed or broken as water changes from one state to another To increase the temperature, molecules must be moving faster- much of the energy added to a system is used to break the H-bonds, only a portion is available to speed up movement of the water molecules (Temp = av. KE) *High Specific Heat (Heat Capacity) Amount of energy required to raise the temperature of water 1 cal/gH 2 O/1 C Importance in Biology? BECAUSE WATER REQUIRES SO MUCH HEAT INPUT/LOSS TO CHANGE ITS TEMP: Oceans and large bodies of water have relatively constant temperatures High water content of organisms help them maintain relatively constant internal temperatures. Biological reactions occur in a relatively narrow temp. range. *High Heat of Vaporization Amount of Heat Energy needed to change 1g of a substance from a liquid to a gas = phase change Water: A calorie is the amount of heat energy required to raise the temp. of 1g of water 1 C Waters Heat of Vaporization- very high compared to other substances due to H-bonds Importance in Biology?? Exothermic Reaction: Sweating: Evaporative cooling- dissipate xs heat as sweat. Nature- leaves stay cool as transpiration occurs *Polar Molecule (Solvent Properties) Water: The Universal Solvent that allows molecules (usually ionic or polar molecules) to dissociate (separate) into individual ions. Example: NaCl salt:dissolved substance is the solute Cushioning: water protects vital organs from jarring *Wherever water goes, either through the air, the ground, or through our bodies, it takes along valuable chemicals, minerals, & nutrients. Biomolecules Ch 3: Biomolecules Organic compounds? contain Carbon Based Very Diverse Group? 4 major H,O,N,C.leads to millions of types of molecules Carbon has 4 Valence electrons So can covalently bond to? Up to 4 elements, including itself When with H P/S: 4 main macromolecules, and their monomers? Proteins Amino Acids (20) Nucleic Acids Nucleotides DNA/RNA Carbohydrates Monosaccharides (Glucose) Sugars Lipids Fatty Acids Carbohydrates C,H,O 2:1 Energy! Monomer: glucose simple = Monosaccharides Disaccharides (sucrose) Polysaccharides Storage: Starch, glycogen, Structure: cellulose chitin- exoskeleton Carbohydrates Formation of a disaccharide Dehydration Synthesis Dehydration synthesis vs. hydrolysis Lipids Composition? Functional Group? C,H,O *No Ratio H:O Carboxyl -COOH Long term storage of energy Component of cell membrane structure Protective surface coating (plant cuticle) Insulation; nerve function (Animals) Basis for many hormones Waxes Phospholipids Steroids Fats and Oils (triglycerides) Naturalfyi Anabolic..fyi Steroids 4 interconnected rings *MAJOR component of all cell membranes phospholipid bilayer Hydrophobic Hydrophilic Amphipathic = "both - dual nature - polar/non- polarPHOSPHOLIPIDS Triglycerides Most complex Primary elements? C, H, O, ****N Monomer? Amino Acid 20 different ones *Functions* *Forms* Proteins Globular and Fibrous Proteins Fibrous Proteins Little or no tertiary structure. Long parallel polypeptide chains. Cross linkages at intervals forming long fibres or sheets. Usually insoluble. Many have structural roles. E.x- keratin in hair and the outer layer of skin, collagen (a connective tissue). -Actin/Myosin- movement -Structure -cytoskeleton Globular Proteins Have complex tertiary and sometimes quaternary structures. Folded into spherical (globular) shapes. Roles in metabolic reactions. E.g.- enzymes, transport hemoglobin, insulin. -antibodies/defense Denatured Protein Nucleic Acids