Biology

at what height did the column of fluid in the tube stop rising? Immediately mark the level of the solution in the glass tube by wrapping a second piece of wet string twice around the tube. Move the string to mark the starting level of the fluid in the glass tube. At 5 minute intervals, […]

Movement of water into a model cell In Exercise 1, as water moves by osmosis into a dialysis bag (our “model cell”), the pressure in the bag increases. You will quantify this pressure change by measuring the height of the water in a glass tube inserted into the bag (See Figure 1). A taller column

The Osmometer Osmotic pressure is the tendency of water to move into a cell. An osmometer is a device designed to measure osmotic pressure by measuring the amount of internal hydrostatic pressure needed to stop the movement of water into a cell. The osmotic pressure experienced by a cell differs under different environmental conditions. Figure

One of the principal ways molecules get in and out of cells is diffusion. Diffusion is defined as the net movement of molecules from areas of higher concentration to areas of lower concentration. For example, if you place a crystal of a purple dye in a glass of water, the purple color spreads out as

Lab 3 – Cell Membranes and Water Balance 8 PLAN AHEAD! This lab requires working with a partner and writing a lab report. Osmosis is the vitally important process by which water moves in and out of cells. Overall, the cells of living organisms are composed of about 75-85% water. The concentration of water is

What happens to the shape of protein molecules when they are heated? Questions For Further Thought 1. Predict what would happen to a living organism exposed to temperatures that fall outside the optimal range for its enzymes. 2. List some familiar adaptations animals have to reduce the effects of temperature extremes on their many vital,

what might explain the changes you observed in the rate of the enzyme-catalyzed reaction at low and high pH values? Analysis and Discussion 1. At what pH values was the rate of reaction greatest? ____ At what pH values was the rate lowest? ____ Are these observations consistent with the hypothesis about the effects of

Effects of pH on enzyme-catalyzed reactions The pH (acidity) of the environment can affect the molecular bonds that maintain the shape of an enzyme’s “active site,” the site on the enzyme molecule responsible for binding to the substrate or substrates. A pH value of 2 is highly acidic, 7 is neutral, and 11 is highly

Effect of temperature on extent of browning Sample Temp (oC) Absorbance after ( ) minutes Any color changes? (see #11 below)   10. If you experience measuring delays, you will need to control for the fact that the reaction product continues to form while you are waiting to measure it. After measuring the absorbance in

PART II: EFFECTS OF ENVIRONMENTAL FACTORS ON RATE OF ENZYME-CATALYZED REACTIONS In this section you and a partner will design and carry out experiments to test the two hypotheses you made at the end of Part I concerning the effects of temperature and pH on enzymes. The quantitative techniques you will be using will allow