September 9, 2016 Objective: Students will be able to analyzed the unique properties of water Warm Up Name the 4 macromolecules and their building blocks Agenda: Warm-up Take out review packet Quiz Unit project Letter ppt

September 9, 2016 biologyortizoldmill@gmail.com Unit project Objective: Students will be able to analyzed the unique properties of water Unit project Letter – let to client ppt Slide 1/P 1 = Client info Slide 2/P 2 – Day 1 and 2 Slide 3 -5/ P3-5 suggestions for a meal plan biologyortizoldmill@gmail.com

Why Does a belly flop hurt? The Unique Properties of Water

The Chemical Makeup of H20 Water is made from covalent bonds Each hydrogen binds to one oxygen The electrons stay closer to the oxygen, making it have a charge. Ask who remember what covalent bonding is.

Water is a polar molecule. Water has a positive pole and a negative pole.

Hydrogen Bonding: The (+) pole of one water molecule is attracted to the (-) side of another water molecule.

Surface tension is the top layer of water molecules cohering to each other to act like a film

Surface Tension Water molecules want to cling to each other. At the surface, there are fewer water molecules to cling to since there is air above. This results in a stronger bond between those molecules that actually do come in contact with one another, and a layer of strongly bonded water (see diagram). This surface layer creates a barrier between the atmosphere and the water.

So a “net” of water molecules forms So a “net” of water molecules forms. When water sticks to itself it is called cohesion.

Capillary action: water can defy gravity when flowing through small tubes. How does blood “feed” every cell, even at the extreme tips of your body?

When water sticks to something else it is called adhesion.

Check for Understanding With your partner, review and summarize what cohesion and adhesion are Come up with a clever way to not get the two confused TIME: 2 minutes Trick to remember: cohesion has “co” in it, which means together (water molecules coming together) adhesion has “ad” in…think adding something different to water

But once it is heated, water holds heat. Specific heat capacity: It takes a great amount of energy to heat up water. But once it is heated, water holds heat.

So, your body is a like a car’s radiator. When blood flows heat is evenly distributed from from the inside out.

Density: Water floats when frozen (it is less dense than liquid). What would happen to life in a winter pond if water sank when frozen?

Universal Solvent: Water dissolves most polar substances. Why is your blood mostly made of water?

List the properties of water. Let’s Review. List the properties of water.

1. Polar 2. Cohesion 3. Adhesion 4. Specific heat capacity 5 1. Polar 2. Cohesion 3. Adhesion 4. Specific heat capacity 5. Floats when frozen – less dense. 6. Surface tension 7. Capillary action 8. Universal solvent

Most biochemical reactions involve solutes dissolved in water. There are two important quantitative proprieties of aqueous solutions. 1. Concentration 2. pH

Acids and Bases An acid is a substance that increases the hydrogen ion concentration in a solution. Any substance that reduces the hydrogen ion concentration in a solution is a base. Some bases reduce H+ directly by accepting hydrogen ions. Strong acids and bases completely dissociate in water. Weak acids and bases dissociate only partially and reversibly. There is only 1 molecule out of 554,000,000 water molecules that is dissociated.

pH Scale Measures the degree of acidity (0 – 14) Most biologic fluids are in the pH range from 6 – 8 Each pH unit represents a tenfold difference (scale is logarithmic) A small change in pH actually indicates a substantial change in H+ and OH- concentrations.

Warm Up: 1. When the cells of most organisms freeze, they burst. Which property of water causes this to occur? a. Water is a universal solvent. b. Water changes temperature rapidly. c. Water is less dense as a solid than as a liquid. d. Water is a nonpolar molecule. 2. Water dissolves many substances. This occurs because water has a. surface tension b. polarity c. specific heat d. cohesion

September 7, 2016 Objective: Students will be able to analyzed the unique properties of water Turn-in Bin Finish lab – observation and water properties Agenda: Warm-up Notes – water Lab Homework: Review Packet