1.
The type of bond that forms between amino acids in order to eventually form a protein is called a....
Correct Answer
D. Peptide bond
Explanation
A peptide bond is the correct answer because it is the type of bond that forms between amino acids to create proteins. A peptide bond is a covalent bond that forms when the carboxyl group of one amino acid reacts with the amino group of another amino acid, resulting in the formation of a peptide chain. This bond is essential for the structure and function of proteins as it allows for the formation of long chains of amino acids. Glycosidic linkage, hydrogen bond, ionic bond, and hydrous bond are not involved in the formation of proteins.
2.
The formation of a protein or polypeptide relies on linking amino acids by way of....
Correct Answer
A. Dehydration synthesis
Explanation
Dehydration synthesis is the correct answer because it is the process by which amino acids are linked together to form proteins or polypeptides. During dehydration synthesis, a water molecule is removed, allowing the amino acids to bond together through a covalent bond. This process is essential for the formation of proteins and is the opposite of hydrolysis, which breaks down proteins by adding water molecules. Hydration and polar covalent bonding are not directly involved in the linking of amino acids to form proteins.
3.
In the typical amino acid shown below, "R" represents:
Correct Answer
C. A variable group, different in each of the 20 amino acids
Explanation
The variable group represented by "R" in the typical amino acid is different in each of the 20 amino acids. This means that "R" can be any one of the 20 different side chains that give each amino acid its unique properties. The side chain can be a simple hydrogen atom, a complex organic group, or anything in between. The specific side chain determines the chemical properties and functions of the amino acid.
4.
When amino acids are bonded into a single long chain, the resulting product is considered to be a protein's....
Correct Answer
A. Primary Structure
Explanation
When amino acids are bonded into a single long chain, it forms the primary structure of a protein. The primary structure refers to the specific sequence of amino acids in the chain, which is determined by the genetic code. This sequence is crucial as it determines the protein's overall structure and function. The primary structure is the first level of protein organization and serves as a foundation for the higher levels of protein structure such as the secondary, tertiary, and quaternary structures.
5.
A chain of amino acids, which is then twisted into an Alpha Helix, or 'folded' into a Beta Pleat, is considered a protein's....
Correct Answer
B. Secondary Structure
Explanation
The secondary structure of a protein refers to the local folding patterns of the amino acid chain. It is characterized by the formation of either an alpha helix or a beta pleated sheet. In the case of an alpha helix, the amino acid chain twists into a right-handed spiral, while in a beta pleated sheet, the chain folds into a zigzag pattern. The secondary structure is important for determining the overall shape and stability of the protein.
6.
A chain of amino acids, that has been twisted or folded, sometimes folds or twists upon itself even more, due to attractions between amino acids. This is an example of....
Correct Answer
C. Tertiary Structure
Explanation
The given scenario describes the folding or twisting of a chain of amino acids, which indicates the formation of a higher-order structure. The primary structure refers to the linear sequence of amino acids, while the secondary structure involves the formation of regular patterns like alpha helices or beta sheets. The tertiary structure is the three-dimensional arrangement of the entire protein molecule, including interactions between amino acids that are far apart in the sequence. Therefore, the correct answer is Tertiary Structure.
7.
If a protein consists of several different polypeptides, each with a complex three-dimensional shape, held together by chemical bonds, it is considered to have a fairly complex ____________ structure.
Correct Answer
D. Quaternary
Explanation
A protein with several different polypeptides, each with a complex three-dimensional shape, held together by chemical bonds, is considered to have a fairly complex quaternary structure. The quaternary structure refers to the arrangement and interactions between multiple polypeptide chains in a protein. This structure is responsible for the overall shape and function of the protein, as it determines how the different subunits come together to form a functional protein complex.
8.
Which of the following is NOT true about Proteins?
Correct Answer
C. They are stored as a nutrient, since they yield more energy than lipids or carbs.
Explanation
Proteins are not stored as a nutrient, as they are primarily used for structural components and chemical reactions in cells. While proteins do provide energy, they do not yield more energy than lipids or carbohydrates. Lipids and carbohydrates are the main sources of energy in the body.
9.
Any protein that can act as a catalyst for certain cellular chemical reactions is considered to be a(n)....
Correct Answer
A. Enzyme
Explanation
Enzymes are proteins that act as catalysts for specific chemical reactions within cells. They facilitate and speed up these reactions by lowering the activation energy required for the reaction to occur. Enzymes are highly specific and can only catalyze a particular reaction or a group of closely related reactions. They play a crucial role in various biological processes, including metabolism, digestion, and DNA replication. Therefore, any protein that can act as a catalyst for certain cellular chemical reactions is considered to be an enzyme.
10.
Proteins embedded in the cellular membrane are often used for many functions. Which of these is NOT a function of membrane proteins?
Correct Answer
E. Cell nutrition
Explanation
Proteins embedded in the cellular membrane have various functions, including cell to cell adhesion, acting as receptor sites for hormones, transporting materials in and out of the cell, and cell identity or recognition. However, cell nutrition is not a function of membrane proteins. Nutrients are typically transported into the cell through other mechanisms, such as specific transport proteins or endocytosis.
11.
A protein produced by a white blood cell in response to some foreign element (bacterium, virus) is called a(n)....
Correct Answer
C. Antibody
Explanation
An antibody is a protein produced by a white blood cell in response to a foreign element such as a bacterium or virus. It is part of the immune system's defense mechanism and helps to neutralize or destroy the foreign substance. Antibodies recognize and bind to specific antigens on the surface of the foreign element, marking it for destruction by other immune cells. Therefore, the correct answer is antibody.
12.
Bacteria or viruses have proteins on their surface that our white blood cells recognize as foreign or 'non-self'. These proteins are called....
Correct Answer
B. Antigens
Explanation
Bacteria or viruses have proteins on their surface that our white blood cells recognize as foreign or 'non-self'. These proteins are called antigens.
13.
The Sodium - Potassium pump is an excellent example of a(n)....
Correct Answer
D. Transport Protein
Explanation
The correct answer is Transport Protein. The Sodium-Potassium pump is a type of transport protein found in the cell membrane. It actively transports sodium ions out of the cell and potassium ions into the cell, against their concentration gradients. This process requires energy in the form of ATP and is essential for maintaining the electrochemical balance and proper functioning of cells.
14.
The diagram below is showing a reaction between three amino acids. When the reaction is complete, the resulting bond and molecule will be, respectively:
Correct Answer
B. Peptide, polypeptide
Explanation
The diagram shows a reaction between three amino acids. When the reaction is complete, the resulting bond will be a peptide bond, which is formed between the carboxyl group of one amino acid and the amino group of another amino acid. The resulting molecule will be a polypeptide, which is a chain of amino acids linked by peptide bonds.
15.
The functional group shown below is a(n):
Correct Answer
C. Amino Group
Explanation
The functional group shown in the image is a primary amine, which is a type of amino group. Amino groups consist of a nitrogen atom bonded to two hydrogen atoms and are commonly found in amino acids, the building blocks of proteins. They are characterized by their ability to act as a base and form bonds with other molecules through their lone pair of electrons on the nitrogen atom.
16.
The functional group shown below is a(n)...
Correct Answer
A. Carboxyl Group
Explanation
The functional group shown in the question is a carboxyl group. This is because it consists of a carbonyl group (C=O) and a hydroxyl group (-OH) attached to the same carbon atom. The carboxyl group is commonly found in organic compounds such as carboxylic acids, which are characterized by their acidic properties.
17.
Several amino acids have the functional group below. It is a(n)....
Correct Answer
E. Sulfhydryl Group
Explanation
The correct answer is "Sulfhydryl Group". Amino acids contain various functional groups, and one of them is the sulfhydryl group (-SH). This group consists of a sulfur atom bonded to a hydrogen atom and is commonly found in cysteine, an amino acid that plays a crucial role in protein structure and function. The sulfhydryl group can form disulfide bonds, which contribute to the stability and folding of proteins.