Why is it important for organisms to regulate internal temperatures or metabolic processes at different temperatures? -Certain vital enzymes will become inactive if the temperature is too cold, and denatured if the temperature is too hot. The organism cannot function without these vital enzymes. 8. Explain how the process of blanching is used in the food industry and why a specific temperature is required.
Part 1: Scemario 4 Carmen conducted an experiment to determine whether salt added to a cup of water affects its freezing point (the temperature at which it freezes). After some research, she hypothesized that the greater the amount of salt dissolved in the water, the lower the temperature at which the water freezes. Water samples were prepared containing equal quantities of water at the same starting temperature. Each sample received a different amount of salt and was placed into a freezer. The length of time it took for each sample to freeze was recorded as shown below.
Thermoregulation is controlled by the hypothalamus, using two sets of thermo receptors one set in the hypothalamus, these measure the temperature of the blood passing the brain (core temperature) and the other based in the skin to measure the external temperature both are needed for the body to make adjustments accordingly to maintain the body temperature. When the body temperature has decreased due to cold environments of the organism the change in
_______in homeostasis, negative feedback is used in the same way, by increasing the stimulus until it is excessive and then decreasing or stopping___________________________________________________ _______________________________________________ Gizmo Warm-up To survive, an organism must be able to maintain stable internal conditions in a changing environment. This process is called homeostasis. The Human Homeostasis Gizmo™ allows you to explore how the human body stays at a nearly constant temperature in different conditions. Notice the Air temp. and Body temp.
Conditions that must remain constant in this experiment include the temperature of the water baths and the volume of peas and beads in the respirometers. The general gas law states that if temperature and volume remain constant, then the pressure of the gas will change in proportion to the number of molecules of gas present. 2. Water moves into the respirometer pipettes because as oxygen is consumed by the peas, the pressure within the pipettes will decrease and thus the negative pressure will draw the water into the pipette. It is important to correct the readings from the peas because the glass beads are used as a control in which no changes should occur in CO2 and oxygen levels due to their abiotic nature.
The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies. There is an equation to determine how much of this heat energy is lost or gained when a reaction is performed. Q = c m (T1-T2) Where: q is the energy in Joules C is the heat capacity, measured in joules per gram per degree Celsius M is the mass of the solution, measured in grams J is the joules G is the grams of water T is the temperature ΔH=ΔE + PΔV = (q p +w) – w = q p Procedure: 1. Follow instructions 1-9 in Appendix A-1 to initialize the MeasureNet workstation. a.
Lab: I Scream, We All Scream for …Colligative Properties!? Introduction: When a solute is added to water the physical properties of freezing point and boiling point change. Water normally freezes at 0oC and boils at 100oC. As more solute is added, the freezing point drops (“freezing point depression”) and the boiling point increases (“boiling point elevation”). This property is useful in our lives.
affect the enzyme activity, to get enzymes working there should be proper ph. to avoid denaturing of enzymes, changes in pH alters ionization of charged amino acids. In an experiment to determine the pH range over which the enzyme catechol oxidase is able to catalyze its substrate, this will also help determine the optimum pH in which enzymes work best. Materials • 7 test tubes • Test tube rack • Metric ruler • China marker • Wash bottle containing 1%
Heats of Solution and Reaction Name: Cindy Hernandez Purpose: The purpose of this experiment is to decided if the chemical reactions are exothermic and endothermic. By finding the differences between each temperature. Overview: For this lab, we had three different chemicals involved NH4Cl, H2SO4, and NaOH. What we did with these chemicals was that we added water, except NaOH we added HCl, was that we combined both mixtures to determine if there was a temperature change. The reason why we're determining if their was a chemical reaction is to identify if it is exothermic or endothermic.
Caffeine & Alcohol Effect on the Water Flea Heart Rate Abstract In this study, water fleas (Daphnia magna), a semi-transparent freshwater crustacean, are used to study the effects of caffeine and alcohol on heart rate. There was a control group used along with the alcohol and caffeine to ensure the results were more accurate. The prediction was the introduction of alcohol and each increased concentration of alcohol, would decrease heart rate and the introduction and subsequent increased concentrations of caffeine would increase heart rate. The results of this experiment proved the prediction to be correct with the alcohol, but the results from the caffeine were hardly noticeable. Methods & Materials