1.
Which of the following is a function of some proteins?
Correct Answer
D. D. Speed up chemical reactions.
Explanation
Proteins are known to act as catalysts, which means they speed up chemical reactions in the body. They do this by lowering the activation energy required for a reaction to occur, making it easier and faster for the reaction to take place. Therefore, option D is the correct answer as it accurately describes one of the functions of proteins.
2.
A glucose molecule contains:
Correct Answer
A. A. six carbon atoms.
Explanation
A glucose molecule contains six carbon atoms.
3.
The building blocks or monomers that make up carbohydrates are:
Correct Answer
C. Monosaccharides.
Explanation
Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen atoms. Monosaccharides are the building blocks or monomers that make up carbohydrates. They are simple sugars, such as glucose and fructose, which can be linked together through chemical reactions to form complex carbohydrates like starch and cellulose. Nucleotides are the building blocks of nucleic acids, amino acids are the building blocks of proteins, and fatty acids and glycerol are the building blocks of lipids. Therefore, monosaccharides are the correct answer as they specifically refer to the building blocks of carbohydrates.
4.
Which of the following molecules is a carbohydrate?
Correct Answer
B. C6H12O6
Explanation
C6H12O6 is a carbohydrate because it follows the general formula of a carbohydrate, which is (CH2O)n. In this case, n is equal to 6, indicating that there are 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms in the molecule. This composition of elements is characteristic of carbohydrates, which are organic compounds that serve as a primary source of energy in living organisms.
5.
Carbohydrates are composed of:
Correct Answer
C. Monosaccharides.
Explanation
Carbohydrates are organic compounds that serve as a major source of energy in the body. They are composed of monosaccharides, which are single sugar molecules. Amino acids are the building blocks of proteins, while nucleic acids are the building blocks of DNA and RNA. Glycerol and fatty acids are components of lipids, not carbohydrates. Therefore, the correct answer is monosaccharides.
6.
The unit molecule of a protein is:
Correct Answer
D. An amino acid.
Explanation
The unit molecule of a protein is an amino acid. Proteins are made up of long chains of amino acids that are linked together by peptide bonds. Each amino acid consists of an amino group, a carboxyl group, and a unique side chain. These amino acids are the building blocks of proteins and are responsible for their structure and function. Glucose, glycerol, and fatty acids are not the unit molecules of proteins; they are molecules that are involved in other biological processes such as energy production and lipid metabolism.
7.
Glucose in cells is used primarily:
Correct Answer
A. As an energy source.
Explanation
Glucose is primarily used as an energy source in cells. It is broken down through a process called cellular respiration to produce ATP, which is the main energy currency of the cell. While glucose can also be used to produce other molecules such as membranes and genetic material, its main role is to provide energy for various cellular processes. Additionally, glucose can be converted into glycogen and stored in the liver and muscles for later use when energy is needed.
8.
The breakdown of a disaccharide may produce:
Correct Answer
A. Glucose
Explanation
When a disaccharide is broken down, it produces glucose. Disaccharides are made up of two monosaccharide units joined together by a glycosidic bond. Hydrolysis of this bond breaks the disaccharide into its constituent monosaccharides. In the case of glucose, it is a monosaccharide and the simplest form of sugar that can be readily used by the body for energy. Therefore, the breakdown of a disaccharide will yield glucose as one of the products.
9.
The bending and folding of a protein molecule would produce a:
Correct Answer
A. tertiary structure
Explanation
The bending and folding of a protein molecule refers to the complex three-dimensional arrangement of its secondary structures, such as alpha helices and beta sheets. This arrangement is known as the protein's tertiary structure. The primary structure of a protein refers to the linear sequence of amino acids that make up the protein chain. Therefore, the correct answer is tertiary structure, as it describes the result of the bending and folding of a protein molecule.
10.
Which of the following is made up of a long chain of glucose molecules?
Correct Answer
B. Starch
Explanation
Starch is made up of a long chain of glucose molecules. It is a complex carbohydrate that serves as a storage form of energy in plants. The glucose molecules in starch are bonded together through glycosidic linkages, forming a linear or branched structure. This arrangement allows starch to be easily broken down into glucose when needed for energy.