Question

Which of the following statements about metabolism are true?

1) Catabolism is the process in which complex substances are broken down, yielding a net output of energy.
2) Metabolism is an integrated system in which many of the same reactions participate in degradative (catabolic) and biosynthetic (anabolic) pathways.
3) Anabolism involves the synthesis of polymeric biomolecules and complex lipids from monomers such as fatty acids and nucleotides.
4) All organisms require an external source of energy, such as glucose or sunlight, for metabolic energy.

Answer 1

The following statements are true

1. Catabolism is the process in which complex substances are broken down, yielding a net output of energy.

Explanation : Catabolism is the set of biochemical reactions that break down complex molecules into simpler ones. Catabolic processes are thermodynamically favorable and spontaneous, so cells use them to generate energy or to file anabolism. Catabolism is exergonic, meaning it releases heat and works via hydrolysis and oxidation. Cells can store useful raw materials in complex molecules, use catabolism to break them down, and recover the smaller molecules to build new products. For example, catabolism of proteins, lipids, nucleic acids and polysaccharides generates amino acids, fatty acids, nucleotides, and monosaccharides, respectively. Sometimes waste products are generated, including carbon dioxide, urea, ammonia, acetic acid, and lactic acid.

Catabolism Examples ;  

a. Dcellular respiration, glucose and oxygen react to yield carbon dioxide and water.

b. In cells, hydroxide peroxide decomposes into water and oxygenMany hormones act as signals to control catabolism. The catabolic hormones include adrenaline, glucagon, cortisol, melatonin, hypocretin, and cytokinesis. Catabolic exercise is aerobic exercise such as a cardio workout, which burns calories as far (or muscle) is broken down.

3. Anabolism involves the synthesis of polymeric biomolecules and complex lipids from monomers such as fatty acids and nucleotides.

Explanation : Anabolism or biosynthesis is the set of biochemical reactions that construct molecules from smaller components. Anabolic reactions are endergonic, meaning they require an input of energy to progress and are not spontaneous. Typically, anabolic and catabolic reactions are coupled, with providing activation energy for anabolism. The hydrolysis of adenosine triphosphate (ATP) powers many anabolic processes. In general, condensation and reduction are the mechanisms behind anabolism

Anabolism Examples;

Anabolic reactions are those that build complex molecules from simple ones. Cells use these processes to make polymers, grow tissue, and repair damage. For example;

a. Simple sugars combine to form disaccharides and water. b. Carbon dioxide and water react to form glucose and oxygen in photosynthesisAnabolic hormones stimulate anabolic processes. Examples of anabolic hormones include insulin, which promotes glucose absorption, and anabolic steroids which stimulate muscle growth. Anabolic exercise, such as weightlifting, which also builds muscle strength and mass.

4. All organisms require an external source of energy, such as glucose or sunlight, for metabolic energy.

Explanation : All living organisms need energy to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is the set of life- sustainable chemical processes that enables stored in molecules into energy that can be used for cellular processes. Animals consume food to replenish energy; their metabolism breaks down the carbohydrates, lipids, proteins and nucleic acids to provide chemical energy for these processes. Plant convert light energy from the sun into chemical energy stored in molecules during the process of photosynthesis.