1.
When does a protein becomes denatured?
Correct Answer
D. All of the above
Explanation
Proteins become denatured when some of the hydrogen bonds are broken, causing their normal shape to become deformed. Additionally, exposure to an acid can also lead to protein denaturation. Therefore, all of the above conditions can cause a protein to become denatured.
2.
What of the following best defines the process of coagulation?
Correct Answer
A. Proteins forming solid or semi-soft clots
Explanation
The process of coagulation is best defined as proteins forming solid or semi-soft clots. Coagulation is a natural process that occurs in the body to stop bleeding and repair damaged blood vessels. When an injury occurs, proteins in the blood called clotting factors come together to form a clot, which helps to seal the wound and prevent further blood loss. This clotting process involves the conversion of soluble proteins into insoluble fibrin, which forms a mesh-like structure to trap blood cells and platelets, leading to the formation of a solid or semi-soft clot.
3.
Which of the following is the best example of coagulation?
Correct Answer
D. All of the above
Explanation
All of the given examples demonstrate the process of coagulation. When egg white is cooked, it changes from a clear liquid to a solid white mass, which is a result of the coagulation of proteins. Curdling during cheese making is also a result of coagulation, where the proteins in milk clump together to form solid curds. Gelatin, when cooled, undergoes coagulation and transforms from a liquid to a solid state. Therefore, all of the given options are examples of coagulation.
4.
What are the causes of protein denaturation?
Correct Answer
D. All of the above
Explanation
Protein denaturation can be caused by various factors, including organic compounds, heat, and pH changes. Organic compounds, such as certain solvents or detergents, can disrupt the protein's structure and cause denaturation. Heat can also lead to denaturation by breaking the weak bonds that hold the protein's structure together. pH changes can alter the charges on the protein molecules, affecting their folding and stability. Therefore, all of these factors can contribute to protein denaturation.
5.
What is it called when O2 is added and removed from a compound?
Correct Answer
A. Oxidation and reduction
Explanation
Oxidation and reduction refer to the process of adding and removing oxygen from a compound. In oxidation, oxygen is added to a compound, while in reduction, oxygen is removed from a compound. This process is commonly seen in chemical reactions where the oxidation state of an element changes. It is an important concept in chemistry and is used to understand various reactions and transformations of compounds.
6.
What are the types of protein denaturation?
Correct Answer
D. All of the above
Explanation
The correct answer is "All of the above" because protein denaturation can occur through various mechanisms. Denaturation by change in pH refers to the alteration in protein structure due to changes in the acidity or alkalinity of the environment. Chemical denaturation involves the disruption of protein structure by the addition of certain chemicals. Denaturation by heat and radiation occurs when proteins are exposed to high temperatures or ionizing radiation, leading to the unfolding and loss of their biological activity. Therefore, all three types mentioned in the options can cause protein denaturation.
7.
Which protein can be found in milk?
Correct Answer
B. Casein
Explanation
Casein is the correct answer because it is a protein that can be found in milk. It is the primary protein present in milk, accounting for about 80% of the total protein content. Casein is responsible for the white color of milk and plays a crucial role in the formation of curds during the production of cheese. It is also a source of essential amino acids and is commonly used in various food products and supplements.
8.
From where does the odor of "rotten" eggs come?
Correct Answer
C. Due to breakdown of H2S atoms
Explanation
The odor of "rotten" eggs comes from the breakdown of H2S atoms. H2S, also known as hydrogen sulfide, is a gas that is produced when organic matter decomposes. It has a distinct smell that is often described as similar to rotten eggs. When H2S molecules break down, they release sulfur compounds that are responsible for the foul odor.
9.
Which statement is true about Albumin, the protein in egg white?
Correct Answer
A. Dissolves in water
Explanation
Albumin, the protein in egg white, dissolves in water. This is because albumin is a water-soluble protein. When mixed with water, the protein molecules disperse and become evenly distributed throughout the water, forming a homogeneous solution. This property allows albumin to be easily incorporated into various recipes and preparations where it can contribute to the texture and structure of the final product.
10.
What happens to a protein when it undergoes denaturation?
Correct Answer
D. All of the above
Explanation
When a protein undergoes denaturation, all of the above mentioned changes occur. Denaturation refers to the process in which a protein loses its natural shape and structure, usually due to exposure to extreme conditions such as heat, pH changes, or chemicals. This leads to the alteration of secondary structures, such as alpha helices and beta sheets, as well as the alteration of tertiary structures, which involve the overall folding and arrangement of the protein. Despite these changes, the peptide bonds that form the primary structure, connecting the amino acids, remain intact. Therefore, all of the given options are correct.