1.
Polymers of polysaccharides, fats and proteins are all synthesized from monomers by
Correct Answer
C. The removal of water
Explanation
Polymers of polysaccharides, fats, and proteins are synthesized from monomers by the removal of water. This process is known as dehydration synthesis or condensation reaction. During this reaction, a water molecule is removed for each monomer added, forming a covalent bond between the monomers. This process allows the monomers to join together and form larger molecules, such as polysaccharides, fats, and proteins.
2.
Carbohydrates normally function in animals as
Correct Answer
D. Energy storage moleucules
Explanation
Carbohydrates function as energy storage molecules in animals. They are broken down into glucose, which is then used as a source of energy for various metabolic processes in the body. Carbohydrates can be stored in the form of glycogen in the liver and muscles, providing a readily available source of energy when needed.
3.
Which of the following is true of saturated fatty acids?
Correct Answer
C. They have a higher ratio of hydrogen to carbon than unsaturated fatty acids
Explanation
Saturated fatty acids have a higher ratio of hydrogen to carbon than unsaturated fatty acids. This means that saturated fatty acids have more hydrogen atoms bonded to the carbon atoms in their structure, while unsaturated fatty acids have double bonds between some of the carbon atoms, resulting in fewer hydrogen atoms. This higher ratio of hydrogen to carbon in saturated fatty acids contributes to their solid state at room temperature, unlike unsaturated fatty acids which are usually liquids at room temperature.
4.
Which type of phospholipid is most important in biological membranes?
Correct Answer
C. pHospHolipid
Explanation
Phospholipids are the most important type of lipid in biological membranes. They have a hydrophilic head and hydrophobic tails, which allows them to form a phospholipid bilayer in cell membranes. This bilayer acts as a barrier, regulating the movement of molecules in and out of the cell. Phospholipids also play a role in cell signaling and membrane fluidity. Therefore, phospholipids are essential for maintaining the structure and function of biological membranes.
5.
The 20 different amino acids have different chemical properties because of different
Correct Answer
C. Side chain (R groups)
Explanation
The 20 different amino acids have different chemical properties because of their side chain (R groups). The side chain is a unique component of each amino acid that determines its specific characteristics and interactions with other molecules. By having different side chains, the amino acids can vary in size, charge, polarity, and hydrophobicity, which in turn affects their behavior and function in protein structures. The side chain plays a crucial role in determining the overall structure and function of proteins.
6.
A change in a protein's three dimensional shape due to disruption of hydrogen bonds, disulfide bridges and ionic bonds is called
Correct Answer
E. Denaturation
Explanation
Denaturation refers to the change in a protein's three-dimensional shape, leading to the loss of its biological activity, due to the disruption of hydrogen bonds, disulfide bridges, and ionic bonds. This disruption can be caused by various factors such as heat, pH changes, or exposure to certain chemicals. Denaturation can result in the protein losing its native structure and function, rendering it inactive or non-functional.
7.
The major function of RNA is to
Correct Answer
B. Function in the synthesis of proteins
Explanation
RNA plays a crucial role in the synthesis of proteins. It acts as a messenger between DNA and the ribosomes, which are responsible for protein synthesis. RNA carries the genetic information from DNA to the ribosomes, where it is used as a template to assemble amino acids in the correct order to form proteins. This process, known as translation, is essential for the functioning and development of all living organisms. Therefore, the major function of RNA is to function in the synthesis of proteins.
8.
Which of the following best describes a nucleotide?
Correct Answer
C. A nitrogen base, a pHospHate group and a five carbon sugar
Explanation
A nucleotide is composed of three components: a nitrogen base, a phosphate group, and a five carbon sugar. The nitrogen base provides the genetic information, the phosphate group connects the nucleotides together, and the five carbon sugar forms the backbone of the nucleic acid molecule.
9.
The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA
Correct Answer
A. Contains less oxygen
Explanation
The sugar in DNA contains less oxygen compared to the sugar in RNA. This is because the sugar in DNA, called deoxyribose, has one less oxygen atom in its structure compared to the sugar in RNA, called ribose. Deoxyribose has a total of four oxygen atoms, while ribose has five. This difference in oxygen content contributes to the structural and functional distinctions between DNA and RNA.
10.
In a double helix structure of nucleic acids, cytosine forms a hydrogen bond with
Correct Answer
E. Guanine
Explanation
Cytosine forms a hydrogen bond with guanine in a double helix structure of nucleic acids. This is a fundamental principle of base pairing in DNA. The hydrogen bond between cytosine and guanine helps stabilize the structure of the DNA molecule by holding the two strands together. This base pairing is specific and complementary, as cytosine always pairs with guanine and adenine always pairs with thymine in DNA.