2/19 Unit 7 Test

we had a test on unit 7
swaggie

Cell Respiration Lab: How Honey Effects Yeast

Abstract: In this lab, we will observe the effect of honey on the process of cellular respiration performed by yeast. Sugar influences cell respiration greatly. Yeast can convert sucrose into glucose and use it during respiration. The most sugar in the test tube will create the greatest concentration of CO2 gas from respiration.

Introduction/Background

In this lab, we experiment with yeast. Yeast is a type of fungus that relies on sugar to provide it with energy so it can grow. Like bacteria, yeast can grow in or on their food source. Once they absorb the sugar, they can break down the molecules into monosaccarides and create ATP (energy). This process is called cellular respiration. Yeast can convert sucrose and fructose into glucose and use it during respiration. The first step of respiration is Glycolysis which occurs in the cytosol. Glucose (6 carbon sugar) is broken down into pyruvate (3 carbon molecule.) The second step is the Krebs cycle that takes place in the mitochondria.This is where the cell generates chemical energy (ATP) from oxidation of pyruvate. The last step is Oxidative phosphorylation which occurs in the inner mitochondrial membrane. This is when large amounts of ATP are released. In cases where there is no oxygen to perform glycolysis, yeast goes through the process of fermentation which makes it possible for ATP to be produced without oxygen. Fermentation regenerates NAD that is needed to take part in glycolysis, allowing it to create more ATP. These processes are necessary for life. Yeast produces carbon dioxide from the break down of glucose. In the lab, we add honey to the yeast. There are 3 monosaccharides that make up honey: fructose, glucose, and sucrose.

Hypothesis: Since honey has sugar in it, if it is added to the yeast, the yeast will convert the sucrose and fructose into glucose during respiration. The most honey in the test tube will create the greatest amount of CO2 gas from respiration.

Materials:

4 tubes

4 CO2 measuring pumps

Yeast

Sucrose

Warm water

Salt

Honey

Timer

Procedure:

1. Set out 4 tubes and each tube add 1g yeast, 1g sucrose, and .1g salt

2. Add warm water to all of the tubes and honey to 3 of the tubes

Tube #1- 35 mL water

Tube #2- 34 mL water, 1 mL honey

Tube #3- 32 mL water, 3 mL honey

Tube #4- 30 mL water, 5 mL honey

3. Cap the tubes and shake them all at the same time

4. After it is dissolved, uncap the tubes and let the tubes sit for 5 minutes.

5. Plug each tube with a CO2 measuring pump. Make sure the pump is set at 2 mL.

6. Every minute, mark where the base of the pump is at.

Results: CO2 Measuring Pump- Recording of each tubes CO2 every minute

Conclusion: Yeast needs glucose to perform cellular respiration. The more glucose there is, the higher energy supply there is for respiration, and the more carbon dioxide produced. So, since honey is mostly made of sugar, the tube that had the most honey (#4 had 5 mL of honey) skyrocketed up the measuring scale. Our control (#1) only had the 1g of sucrose which allowed it to get up to 3.7 mL of CO2. Test tube #2 had 1 mL of honey and went up to 4.2 mL of CO2. Test tube #3 had 3 mL of honey and went up to 5.8 mL of CO2. As you can see, sugar majorly influences the rate of cell respiration in yeast. Our control was tube #1 and the variable was the honey. A potential source of error would be not uncapping the tubes which would not let the yeast get any oxygen to perform glycolysis. 

2/5 Jello Lab!!!!!!!!!!

Jello is made of collagen (protein) which comes from cow and pig bones, hooves and connective tissue. Collagen is all over our body. Manufacturers grind up the parts and treat them with a strong acid/base to break down the cellular structures and release proteins (like collagen) Then it is boiled, and the collagen is partially broke down and the result is gelatin. Collagen gives jello the ability to gel.

Pineapple can be added to the jello desert. Real pineapple contains an enzyme called bromelain.

On the directions for jello, it says not to use fresh pineapple, and instead use canned. We designed an experiment to explain why certain types of pineapple work and why some do not.

Experiment- Canned or fresh pineapple- How the enzyme bromelain effects collagen in jello.

We had three trays of jello.
#1: Regular Jello
#2: Jello with canned pineapple- Does gel
#3: Jello with fresh pineapple- Does not gel


Fresh pineapple contains the enzyme bromelian which can separate amino acids. So, since collagen is a protein, when fresh pineapple is used, the bromelian breaks up the collagen in the jello and does not allow it to set and gel.

Canned pineapple has been heated by manufacturers during the canning process. Once the enzyme, bromelain is heated, it is neutralized (denaturalized) and completely changes it shape forever. It will not be able to fit back into the operon system, and will not work. Bromelain then cannot break up the collagen in Jello and the jello will be able to set and gel.

Forensics Quiz

A twenty-year old man was found supine on Thompson Creak Trail with a bullet would. The entrance of the wound was on the left lateral side 1 cm above the third rib. The exit wound was 5 cm above the belly button in the umbilical region. While tracing the bullet path you notice at the entrance the bullet travels in the frontal plane with a 45-degree downward angle. On inspection of the right side of the rib cage by x-ray you observe the 8th rib fractured. Fragments of the bullets are then traced to the final exit wound. What is the leading differential diagnosis (and why) and what are three plausible alternatives and how would you rule them out.

Leading cause of death: Blood loss
-Went to the 3rd rib on left lateral side where the heart is
Most likely severed arteries causing internal bleeding

Alternatives
1) Shock
Would of happened after the heart was hit

2) Lung puncture
Would of happened after the heart was hit, since it was going at an angle

3) Punctured fluid organs which lead to poisoning
Once again, would have happened after the heart was hit