Equilibrium and Equilibrium and Negative FeedbackNegative Feedback

EquilibriumEquilibrium If something is in equilibrium it is If something is in equilibrium it is

balancedbalanced

HomeostasisHomeostasis The body’s way of staying stable on The body’s way of staying stable on

the inside despite what happens the inside despite what happens outsideoutside

Sweating to cool offSweating to cool off Shivering to warm-upShivering to warm-up

Negative FeedbackNegative Feedback Process that turns itself off when Process that turns itself off when

condition is metcondition is met ThermostatThermostat

-too hot AC turns on-too hot AC turns on-Cools off AC turns off-Cools off AC turns off-Warms up AC turns on….-Warms up AC turns on….

Negative Feedback Ex. #1Negative Feedback Ex. #1 Maintaining TemperatureMaintaining Temperature

Body must stay at constant temperatureBody must stay at constant temperature

Too hotToo hot Body Body SweatsSweats Too coldToo cold Body Body ShiversShivers

Negative Feedback Ex. #2Negative Feedback Ex. #2

Maintain Glucose levelsMaintain Glucose levels Glucose-sugarGlucose-sugar

too much or too little sugar can kill youtoo much or too little sugar can kill you Hormone: chemical that tells body what Hormone: chemical that tells body what

to doto do Insulin: hormone that tells cells to take in Insulin: hormone that tells cells to take in

sugarsugar1.1. Eat sugarEat sugar2.2. Pancreas produces insulinPancreas produces insulin3.3. Tells cells to take in sugarTells cells to take in sugar4.4. Cells take in sugarCells take in sugar5.5. Pancreas stops producing insulinPancreas stops producing insulin

DiabetesDiabetes Pancreas does not produce enough Pancreas does not produce enough

insulininsulin Pancreas produces too much insulinPancreas produces too much insulin

Must manually regulate sugar and Must manually regulate sugar and insulin insulin

Negative Feedback Ex. #3Negative Feedback Ex. #3 Water Equilibrium in plantsWater Equilibrium in plants

DiffusionDiffusion: Movement of water through : Movement of water through a membranea membrane

Moves from full to emptyMoves from full to empty Moves from fresh to saltyMoves from fresh to salty High to lowHigh to low

Water Equilibrium in PlantsWater Equilibrium in Plants

Turgor PressureTurgor Pressure: the pressure of : the pressure of water on a cell wall in a plantwater on a cell wall in a plant

Turgor pressure high: no water comes inTurgor pressure high: no water comes in Turgor pressure low: water moves into plantTurgor pressure low: water moves into plant*More Turgor pressure the happier a plant *More Turgor pressure the happier a plant

lookslooks

Turgor PressureTurgor Pressure

Negative Feedback #4Negative Feedback #4 Water equilibrium in animalsWater equilibrium in animals

Thirsty-drink waterThirsty-drink water Kidney’s functionKidney’s function regulate water regulate water

remove wasteremove waste Too much water: urine is more clear (little Too much water: urine is more clear (little

urea), urinate more frequentlyurea), urinate more frequently Not enough water: urine is dark (more Not enough water: urine is dark (more

urea), smells bad, urinate lessurea), smells bad, urinate less