Biochemistry Name: Practice Questions

Transcription

1 Name: Practice Questions 1. Carbohydrate molecules A and B come in contact with the cell membrane of the same cell. Molecule A passes through the membrane readily, but molecule B does not. It is most likely that molecule A is A) a protein, and B is a lipid B) a polysaccharide, and B is a monosaccharide C) an amino acid, and B is a monosaccharide D) a monosaccharide, and B is a polysaccharide 2. If a specific carbohydrate molecule contains ten hydrogen atoms, that same molecule would most probably contain A) one nitrogen atom B) ten nitrogen atoms C) five oxygen atoms D) twenty oxygen atoms 3. An inorganic molecule required by green plants for the process of photosynthesis is A) oxygen B) starch C) carbon dioxide D) glucose 4. In which type of molecule is the ratio of hydrogen to oxygen usually 2 to 1? A) lipid B) protein C) carbohydrate D) glycerol 5. Which chemical formula represents a carbohydrate? A) CH4 B) C3H7O2N C) Cl2H22O11 D) CO2 6. Which substances dissolved in the cytoplasm of an ameba enable it to carry on life-sustaining activities? A) inorganic compounds, only B) organic compounds, only C) both inorganic and organic compounds D) neither inorganic nor organic compounds 7. Base your answer to the following question on the types of molecules in the list below and on your knowledge of biology. Types of Molecules (A) Amino acid (B) Fatty acid (C) Monosaccharide (D) Glycerol Which types of molecules are used for the synthesis of a lipid? A) A and B B) B and D C) A and C D) C and D 8. Base your answer to the following question on the chemical reaction represented below and on your knowledge of biology. The molecule represented by structural formula A is classified as an organic molecule because it contains A) hydrogen and carbon atoms B) a double covalent bond C) nitrogen and hydrogen atoms D) a variable functional group

2 Base your answers to questions 9 through 11 on the diagram below and on your knowledge of biology. The diagram represents molecules involved in protein synthesis. 14. Some structural formulas of organic molecules are shown below. 9. The building blocks of molecule 3 are known as A) amino acids B) DNA molecules C) fatty acids D) RNA molecules 10. Where do the chemical reactions that are coded for by molecule 2 take place? A) in the vacuole B) on the plasma membrane C) in the lysosome D) at ribosomes 11. Molecule 3 is formed as a result of A) deamination B) dehydration synthesis C) enzymatic hydrolysis D) oxidation Which structural formulas represent carbohydrate molecules? A) 1 and 5 B) 2 and 4 C) 3 and 2 D) 4 and Which elements are present in all organic compounds? A) hydrogen and oxygen B) nitrogen and oxygen C) nitrogen and carbon D) hydrogen and carbon 13. Enzymes are produced as a direct result of which process? A) protein synthesis B) photosynthesis C) respiration D) enzymatic hydrolysis

3 15. Base your answer to the following question on the diagram below. For each of the following phrases, select the molecule, chosen from those shown below, which is best described by that phrase. An example of a carbohydrate A) 1 B) 2 C) 3 D) 4 E) Base your answer to the following question on The diagram below represents the building block of a large molecule known as a 19. Compound X increases the rate of the reaction shown below. A) protein B) fatty acid C) carbohydrate D) nucleic acid 17. The process by which glucose is converted to starch is known as A) protein hydrolysis B) dehydration synthesis C) chemical digestion D) cellular respiration 18. Which chemical reaction is represented by the diagram below? Compound X is most likely A) an enzyme B) a lipid molecule C) an indicator D) an ADP molecule 20. Photosynthesis transforms molecules of water and carbon dioxide into molecules of A) carbohydrate and oxygen B) carbohydrate and nitrogen C) polypeptide and oxygen D) polypeptide and nitrogen 21. The diagram below represents some steps in a chemical reaction involving a carbohydrate. A) dehydration synthesis of a dipeptide B) hydrolysis of a polypeptide C) dehydration synthesis of a lipid D) hydrolysis of a disaccharide Which substance must be added at Y to complete this reaction? A) water B) protease C) DNA D) RNA

4 22. In a living cell, which compound serves primarily as a substance in which most molecules and ions are dissolved? A) glycerol B) glucose C) water D) cellulose 23. Luciferin is a molecule that, when broken down in fireflies, produces heat and light. The rate at which luciferin is broken down in cells is controlled by A) a carbohydrate B) a simple sugar C) an enzyme D) a complex fat 24. Base your answer to the following question on the chemical reactions below and on your knowledge of biology. 26. The diagram below illustrates a biochemical process that occurs in organisms. The substance labeled "catalyst" is also known as A) a hormone B) an enzyme C) an antibody D) an inorganic compound 27. In the enzyme-controlled reaction represented by the word equation below, which molecules are considered the substrate? The enzymes needed for these chemical reactions are indicated by letters? A) W and X B) A and C C) B and D D) B and C 25. Lipase, maltase, and protease are members of a group of catalysts known as A) enzymes B) hormones C) carbohydrates D) fats monosaccharide + monosaccharide disaccharide + water A) monosaccharide and monosaccharide B) disaccharide and water C) monosaccharide and water D) monosaccharide and disaccharide 28. Which substance plays a major role in most of the chemical reactions that occur in a living cell? A) water B) glycogen C) glycerol D) maltose 29. Which activity completes an enzyme-controlled reaction? A) synthesis of coenzymes by enzymes B) initial formation of an enzyme-substrate complex C) separation of the enzyme and the products of the reaction D) destruction of the enzyme 30. The enzyme salivary amylase will act on starch, but not on protein. This action illustrates that salivary amylase A) contains starch B) is not reusable C) is chemically specific D) lacks protein

5 Base your answers to questions 31 and 32 on the diagram below which represents an enzyme controlled reaction and on your knowledge of biology. 31. This reaction best represents A) dehydration synthesis B) aerobic respiration C) hydrolysis D) fermentation 32. Which number indicates the enzyme-substrate complex? A) 1 B) 2 C) 3 D) 4