Water in Living Things - Properties, States, and Polarity

Water in Living Things & Properties of Water Water in the cells - All living things are made of one or multiple cells - All cells have cytoplasm - Cytoplasm: the main components are the cytosol (a gel-like substance), organelles (ex. mitochondrion), macromolecules, and ion...

Water in Living Things & Properties of Water Water in the cells - All living things are made of one or multiple cells - All cells have cytoplasm - Cytoplasm: the main components are the cytosol (a gel-like substance), organelles (ex. mitochondrion), macromolecules, and ions! Water in the cells - Cytosol in plant and animal cells Do bacteria have cytosol? Water in the cells - Cytosol: a gel-like substance is about 70 to 80% water and usually colorless - Cellular metabolism occurs inside this watery content - Water is needed for cellular processes such as photosynthesis Water around the cells - Tissue: a group of cells with a similar function - Connective tissue: cellular component + non cellular component - Blood is a connective tissue: 45 % red/white blood cells + 55% blood plasma - Blood plasma is about 92% water Water in a human being - Water compromises approximately 60-70 percent of your body - Water is critical for life ater in Other Living Things - Water compromises approximately 60-95 percent of different living things! - So……….water is critical for life! ter even since the beginning of life! - Actually, life originally evolved in a marine (water) environment - First macromolecules, then organelles, then cells! - Hydrothermal vents on the deep ocean: no light, but lots of water and crazy nutrients! ter even since the beginning of life! 1. Which organ/tissue of the human body has the highest percentage of water? a) brain b) blood c) heart d) bones e) muscles ter even since the beginning of life! 1. Which organ/tissue of the human body has the highest percentage of water? a) brain b) blood c) heart d) bones e) muscles do we already know about the chemical structure of w 1. The water chemical formula is _____________. a) H2O b) H2O2 c) None of the above 2. Hydrogen and oxygen atoms are hold together by _________ bonds. d) covalent e) ionic bonds f) strong bonds g) None of the above do we already know about the chemical structure of w 3) Water molecules are __________. a) polar b) nonpolar c) None of the above 4) In the covalent bond between an oxygen and a hydrogen (H-O), the oxygen atom attracts electrons a bit more strongly than the hydrogen does. d) True e) False Water’s Polarity Hydrogen and oxygen form covalent bonds Slightly positive charge on hydrogen (H+) and a slightly negative charge on oxygen (O-) Water’s Polarity Water’s polarity contributes to water’s properties of attraction Each water molecule attracts other water molecules, forming hydrogen bonds Water’s Polarity Water also attracts or is attracted to other polar molecules (such as water!) and ions Substances that interact or dissolves in water are called hydrophilic hydro=water, - philic=loving dium Chloride + Water = Ions + Water Salt is made up of sodium chloride Chemical formula NaCl The positive portion of water molecules (hydrogen+) attracts the ___________________. a) negative chloride ions (Cl-) b) positive chloride ions (Cl+) c) neutral chloride ions (Cl) d) None of the above dium Chloride + Water = Ions + Water Salt is made up of sodium chloride Chemical formula NaCl The positive portion of water molecules (hydrogen+) attracts the negative chloride ions (Cl-) The negative portion of water molecules (oxygen-) attracts the positive sodium ions (Na+) dissolved in Water: Ions dissolved in the Cytosol What would happen with the sodium chloride (NaCl) when in reacts with the cytosol of a cell? Think Pair Share + dissolved in Water: Ions dissolved in the Cytosol NaCl + cytosol = negative chloride ions + positive sodium ions + cytosol dissolved in Water: Ions dissolved in the Cytosol Importance of ions in cellular processes is highly relevant! For example: A decrease of chloride ions (Cl-) in the egg’s cytosol changes the electronegativity of the cytosol from negative to positive dissolved in Water: Ions dissolved in the Cytosol For example: A decrease of chloride ions (Cl-) in the egg’s cytosol changes the electronegativity of the cytosol from negative to positive This helps to________________ __________________ __________________ _ hat will we continue to learn about water? Properties of water such as: a) Water’s States: Gas, Liquid, and solid b) Water’s High Heat Capacity c) Water’s Heat of Vaporization d) Water’s Solvent Properties e) Water’s Cohesive and Adhesive Properties ater’s States: Gas, Liquid, Solid - Liquid water: hydrogen bonds constantly form and break as the water molecules slide past each other ater’s States: Gas, Liquid, Solid - Gas water: when the heat rises as water boils, the water molecules’ higher energy causes hydrogen bonds to break completely and allows water molecules to scape into the air (steam or water vapor) ater’s States: Gas, Liquid, Solid - Solid water: when water temperature reduces and water freezes, the water molecules form a crystalline structure maintained by hydrogen bonding -Water’s lower density in its solid form is due to the way hydrogen bonds orient as they freeze: the water molecules push farther apart compared to liquid water -This is why, ice floats at the surface of liquid water -Iceberg or ice cubes in water! ater’s States: Gas, Liquid, Solid - What are the correct labels for the following water’s states drawings? 1 2 3 a) 1-Solid, 2-Liquid, 3-Gas b) 1-Liquid, 2-Solid, 3-Gas ater’s States: Gas, Liquid, Solid -Solid: The ice crystals that form upon freezing rupture the delicate cell membrane ater’s States: Gas, Liquid, Solid -Solid: The ice crystals that form upon freezing rupture the delicate cell membrane and proteins that are essential for living cells to function (ex. red blood cells) ater’s States: Gas, Liquid, Solid -Solid: The ice crystals that form upon freezing rupture the delicate membrane and other organelles and proteins that are essential for living cells to function - Solution: Adding a solution (glycerol) that binds with the hydrogen bonds of water so makes difficult to form ice crystals (until -37.8C) Water’s High Heat Capacity - Water’s high heat capacity is because hydrogen bonding among water molecules It takes water a long time to heat and a long time to cool! Water’s High Heat Capacity -Water has the __________ specific heat capacity of any liquid. a) lowest b) highest c) None of the above Water’s High Heat Capacity - It takes water a long time to heat and a long time to cool. -Blood plasma is mostly water: it is a great way to use water to disperse and save heat in the body Water’s High Heat Capacity Water (blood plasma), water’s heat capacity, and fever! Water’s Solvent Properties - Water is a polar molecule: slightly positive and slightly negative charges - Ions and polar molecules can readily dissolve in it - Water is a great solvent! - Ions and polar molecules will form hydrogen bonds with water, surrounding the particle with water water molecules (sphere of hydration) - Example, table salt (NaCl) + water = Na+ + Cl- + water! ter’s Cohesive and Adhesive Properties - Have you ever filled a glass of water to the very top and then slowly added a few more drops? - Before it overflows, the water forms a dome-like shape above the rim of the glass. - This is because of cohesion - In cohesion, water molecules are attracted to each other because ter’s Cohesive and Adhesive Properties - Cohesion allows for surface tension - Surface tension is the capacity of a substance to withstand rupturing when placed under tension or stress - Or, scrap or paper floats on the top of water, even though paper is denser than water! - A water strider can ter’s Cohesive and Adhesive Properties - Attraction is sometimes stronger than water’s cohesive forces, especially when the water is exposed to charged surfaces such as capillary tubes - Water “climbs” up the capillary tube! ter’s Cohesive and Adhesive Properties - Also, water appears to be higher on the tube's sides than in the middle. This is because the water molecules are attracted to the capillary's charged glass walls more than they are to each other and therefore adhere to it. ’s Cohesive and Adhesive Properties in Living Things - Water transport from the roots to the leaves - Adhesive forces create a “pull” on the water column - Pull results from the tendency of water molecules evaporating on the plant’s surface to stay connected with the water molecules below them