Bed Room Temperature Lab

The dependent variable in the experiment was the temperature and energy absorbed by the water.

One gram of liver was sliced into pieces, then 10ml of homogenization buffer was added to it. The mixture of the liver and homogenization buffer was then placed into a homogenizer to make the liquid slurry. Once the slurry was made it was placed into a 50ml falcon tube to then be placed in the centrifuge. The slurry was centrifuged for 2 minutes at 2000rpm. Once the spin in the centrifuge was complete, the slurry had separated, the most dense particles to the bottom of the tube forming sediment and the lighter (liver succinate dehydrogenase enzyme) also known as the supernatant. The supernatant was extracted from the falcon tube and placed into a test tube. The tube was then kept at a low temperature, (in an ice bath) until it was required for use.

The materials that were used/needed in this experiment were a penny, water, soap, rubbing alcohol, a pipet, and a beaker.

• Fourthly, we kept the temperature at a constant 25°C using a water bath. At low temperatures, an increase in temperature causes an exponential increase in enzyme activity. This is because an increase in temperature provides more kinetic energy for the collisions of enzymes and substrates, so

-VariablesoIndependent:The temperature of the milkoDependent:The time taken for the milk to solidifyoControlled:The same amount and type of milk usedThe same amount and concentration of enzyme mixture usedThe same test tube sizeResults:-TableAmount of enzyme mixture (mL)Amount of milk (mL)Temperature (oC)Time for milk to clot (min)Ex: 1 Ex: 2 Average2.551060+60+60+2.552034.2036.0035.12.55303.554.203.882.55402.102.252.182.55505.004.454.73Discussion:The experiment showed that changing the temperature did affect the rate at which the milk solidified. At low temperatures of 10oC and 20oC the milk took the longest to solidify and at 10oC did not even go lumpy after an hour. As the temperature increased the speed at which it reacted got faster until it reached around 40oC where the speed began to drop.

As the temperature increases, so will the rate of enzyme reaction. However, as the temperature exceeds the optimum the rate of reaction will decrease.

Three factors that can affect the rate of reaction are temperature, pH and the salinity.

7 Corvettes These are used instead of test tubes as corvettes are required if a colorimeter is to be used. One corvette is needed for each pH and one for the control. These can then be reused for the repeats. Syringe calibrated at 0.1 cm³ intervals

Enzymes are proteins which can catalyse chemical reactions without changing themselves. The enzyme lipase breaks down the fat in dairy products such as full-cream milk for people who are lactose intolerant. Lipase acts on its specific substrate, lipids produces fatty acids. If enzyme concentration increases, random collisions between the substrates and active sites of enzyme increase due to the increasing amount of active sites which allow more collisions to happen, so the rate of breakdown of lipids to simpler substances will increase. During the experiment, sodium carbonate solution and pH indicator phenolphthalein will be added ahead of

The aim of the experiment will be to investigate how varying water temperatures influence the time of a chemical reaction, in this case being, a combination of Sodium Thiosulfate and Hydrochloric Acid.

This is a sensible task to do after each round, but upon starting the next round it is only clean for a short time before the lack of hand washing contaminates the items on the trolley once more.

The first thermometer used had the same basics as today using a glass test tube and mercury or coloured alcohol.

Once again, after the reaction, we need to clean the products, to remove namely the other reagents used during the reaction. The protocol for this reaction is described in annex n°5

Smilow Center for Translational Research, Philadelphia. 9th floor. Tissue Culture Room. My arms in pink lab coat stretched out into the hood, and my hands in blue sterilized gloves suspended in the air. In my left hand, I had a lidless 50 mL tube filled with red culture media between my index finger and my middle finger, and an empty 15 mL tube with lid on between my middle finger and ring finger. In my right hand, I held up a pipette gun, and in the 10 mL glass pipette beneath there were hepatic cells that I had been cultured for half a month. I never felt so desperate when I accidentally knocked over the only tube rack 10 seconds ago. And I was stuck. I tried to unscrew the empty tube with my little fingers but almost spilled the media. I wanted to put the pipette down somewhere but my baby cells would not appreciate to live with strange fungus or other contaminants for the rest of their life.

Temperature, pH and the concentration of substances all affect the rate at which enzymes function. The optimum temperature in which the reactions take place is about 37 degrees Celsius and any deviances from this affect the reaction rate as shown in Figure 1. As the temperature decreases from the optimum,