Respuesta :
Protein Denaturation
NAME OF MAIN PROTEIN: TEMPERATURE: OBSERVATION:
EGGS: - 144°F - Then four eggs were cracked into a bowl and separate the yolk from the egg whites. Then was poured the raw egg whites into a saucepan and turn the stove on low heat, then placed the thermometer. The temperature of the egg whites began to increase 80°F. The texture began to become tough and rubber like. The temperature began to increase again to 160°F.
MILK: - 180°F - Two cups of milk was then poured the into a clean saucepan, then was turned it on low heat and inserted the thermometer into the saucepan. The temperature of the milk began to increase to 80°F. The color stayed the same and the texture began to thicken.
HAIR: - 225°F - The oven was then preheated to 200°F, then put aluminum foil over your baking sheet. Hair was revieved from a hair brush and placed was on the baking sheet, then put the baking sheet in the oven. The hair heated for 5 minutes then increased the oven to 225°F, then it heated for another 5 minutes. The texture of the the hair became stiffer and dry.
Questions:
1. What is the most abundant type of protein in egg white? What do you think its purpose is?
2. What is the most abundant type of protein in milk? What do you think its purpose is?
3. What is the most abundant type of protein in human hair? What do you think its purpose is?
4. What happens when a protein denatures?
5. What conditions might cause a protein to denature (list at least two)?
Answers:
1. The most abundant type of protein in egg white is ovalbumin is the most abundant protein in albumen.
2. The most abundant type of protein in milk is caseins.
3. The most abundant type of protein in human hair is biomaterial primarily composed of protein, especially alpha-keratin.
4. Denaturation of proteins involves the destruction of the tertiary and secondary structure.
5. Conditions that might cause a protein to denature is the heat increases the knortic energy which causes the molecules to vibrate so rapidly and violently that the bonds are disrupted, and the heat can disrupt hydrogen bonds and non-polar hydrophobic interaction.
Question:
1. About at which temperature did the protein in eggs denature? How could you tell?
2. About at which temperature did the protein in milk denature? How could you tell?
3. About at which temperature did the protein in hair denature? How could you tell?
4. Why do you think different proteins denature at different temperatures?
5. Why might it be useful to protein?
Answer:
1. After a few minutes, the temperature of the eggs increased to 80°F, then five minutes later it increased agin to 160°F. The eggs then began to become tough and rubbery.
2. After a few minutes, the temperature of the boiling milk increased to 80°F. It then became a thick consitantsy.
3. After the hair was in the oven set at 200°F, the hair became stiff like, then was bumped up to 225°F. It then became stiffer and dry.
4. Yes, different proteins denature at different temperatures can melt above 106°F.
5. Denature a proteins change their structure in the presence of certain chemicals, acids or bases.
In this assignment, data was collected throughout the experiments. During the egg white experiment, the temperature rose of the egg whites began to increase 80°F, then increase again to 160°F, texture began to become tough and rubber like. During the milk experiment, temperature of the milk began to increase to 80°F, the color stayed the same and the texture began to thicken. During the hair experiment, the hair heated for 5 minutes in the 200, the oven was increased to 225°F. Then heated for another 5 minutes, then the texture of the the hair became stiffer and dry.
Material:
⦁ 4 eggs
⦁ Two cups of milk
⦁ Your own hair from a hairbrush
⦁ Small saucepan
⦁ Mixing bowl
⦁ Baking tray
⦁ Aluminum foil
⦁ Candy Thermometer
⦁ Stove and Oven