Chapter 2 introduction To Cellular Metabolism

Question 1

1. What is the term used to describe the sum total of all chemical reactions in a living organism a) Homeostasis b) Metabolism c) Photosynthesis d) Respiration

Answer 1

Explanation: The excerpt defines metabolism as “the sum total of all the chemical reactions or changes going on in the cells…”

Question 2

2. Which of the following is NOT a characteristic of catabolic reactions a) Breakdown of molecules b) Release of energy c) Synthesis of complex molecules d) Often involves oxidation

Answer 2

Explanation: Catabolic reactions are primarily involved in breaking down complex molecules into simpler ones releasing energy in the process. Anabolic reactions on the other hand are responsible for building complex molecules.

Question 3

3. Anabolic reactions are characterized by a) Release of energy b) Breakdown of molecules c) Requirement of energy d) Formation of simpler molecules

Answer 3

Explanation: Anabolic reactions are energy-requiring processes that synthesize complex biomolecules from simpler precursors.

Question 4

4. Organisms that can use oxygen as an electron acceptor in energy-producing pathways are called a) Anaerobes b) Aerobes c) Heterotrophs d) Autotrophs

Answer 4

Explanation: The excerpt defines aerobes as organisms that can use oxygen for energy production.

Question 5

5. Which of the following is an example of an obligate aerobe a) Escherichia coli b) Clostridium botulinum c) Humans d) Yeast

Answer 5

Explanation: The excerpt specifically mentions humans as an example of obligate aerobes meaning they require oxygen for survival.

Question 6

6. What type of reaction releases energy as heat a) Exothermic b) Endothermic c) Neutral d) Reversible

Answer 6

Explanation: Exothermic reactions are defined as those that release energy often in the form of heat.

Question 7

7. In living organisms exothermic reactions are also known as a) Catabolic reactions b) Anabolic reactions c) Photosynthetic reactions d) Hydrolytic reactions

Answer 7

Explanation: The excerpt states that exothermic reactions in organisms are called catabolic reactions.

Question 8

8. Endothermic reactions in organisms are referred to as a) Catabolic reactions b) Anabolic reactions c) Oxidation reactions d) Reduction reactions

Answer 8

Explanation: The excerpt explicitly links endothermic reactions in organisms with anabolic reactions.

Question 9

9. What is the primary function of metabolic pathways a) To store genetic information b) To transport molecules across cell membranes c) To organize and regulate metabolic reactions d) To synthesize hormones

Answer 9

Explanation: The excerpt highlights that metabolic pathways are the “organizational units of metabolism” ensuring controlled and coherent metabolic activity.

Question 10

10. Which of the following plays a crucial role in controlling the rate and specificity of metabolic reactions a) Hormones b) Enzymes c) Lipids d) Carbohydrates

Answer 10

Explanation: The excerpt points out that enzymes catalyze specific reactions thereby regulating the flow of metabolic processes within the cell.

Question 11

11. Facultative anaerobes are organisms that a) Require oxygen for survival. b) Are poisoned by oxygen. c) Can survive with or without oxygen. d) Only use oxygen for energy production.

Answer 11

Explanation: Facultative anaerobes are described as organisms that can adapt to anaerobic conditions when necessary using alternative electron acceptors instead of oxygen.

Question 12

12. The breakdown of glucose is an example of a) An anabolic reaction b) An exothermic reaction c) A photosynthetic reaction d) An endothermic reaction

Answer 12

Explanation: The excerpt uses the breakdown of glucose as an example of an exothermic reaction as it releases energy needed for cellular processes.

Question 13

13. The joining of amino acids to form a protein is an example of a) A catabolic reaction b) An exothermic reaction c) An endothermic reaction d) A hydrolysis reaction

Answer 13

Explanation: The formation of a protein from amino acids is presented as an example of an endothermic reaction highlighting its energy-requiring nature.

Question 14

14. Define metabolism

Answer 14

Answer:Metabolism is the sum of all chemical reactions and processes that occur within a living organism to sustain life. These reactions are responsible for converting nutrients into energy and building blocks for cellular components.

Question 15

15. Provide an example of a metabolic pathway

Answer 15

Answer: Glycolysis is an example of a metabolic pathway. It is a series of reactions that break down glucose into pyruvate generating ATP (energy currency of the cell) in the process.