本题目来源于试卷: Interaction & Interdependence C.1 Enzymes & Metabolism，类别为 IB生物学
[单选题]
Which of the following describes some types of extracellularzg1 h.u77zzazy;;tuj ;v97qq0flo4 z+y rhn6weh zf- enzymes?
A. Enzymes that are located in the mitochondria
B. Enzymes that are involved in various metabolic pathways in the Krebs cycle
C. Enzymes that are used for the chemical breakdown of nutrients in the digestive system
D. Enzymes that are found in lysosomes
参考答案: C
本题详细解析:
Extracellular enzymes a p2h0 en4doj3f+b) qj;6;mv:rfck zakre secreted by cells and function outside of cells, like digestive enzymes, which break down complex molecules into simpler prk4nb pmv a;) 20rez63ohf;dqk :jcj f+oducts that can be absorbed.
Intracellular enzymes are located inside the cell and can be cytosolic or within organelles like the mitochondria (Choice A)
Intracellular enzymes are involved in metabolic pathways, such as the Krebs cycle, and catalyse reactions that contribute to the growth, maintenance and survival of organisms (Choice B).
Lysosomes are membrane-bound vesicles containing digestive enzymes such as glycosidases and peptidases. The enzymes are in membrane-bound sacs, mainly inside animal cells, so therefore are intracellular enzymes. (Choice D).
Examples of extracellular enzymes are digestive enzymes like amylases and lipases, and examples of intracellular enzymes are Krebs cycle enzymes, DNA or RNA polymerases, and hexokinases.
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