Which process is anabolic?

Question

Which process is anabolic??  
A. Glycolysis  
B. Lipid synthesis  
C. Protein degradation  
D. Oxidative phosphorylation

Accepted Answer

Correct Answer: (B)Lipid synthesis. 
Rationale: Lipid synthesis is a biosynthetic process that builds complex molecules from simpler ones, which defines anabolism.Anabolism encompasses the set of metabolic pathways that construct larger, more complex molecules from smaller precursors. These processes are endergonic, meaning they require an input of energy, typically in the form of ATP. Anabolic pathways are essential for growth, repair, differentiation, and the storage of energy reserves, building the proteins, nucleic acids, carbohydrates, and lipids that constitute cellular structures.A) GlycolysisGlycolysis is a universal catabolic pathway. It involves the breakdown of one molecule of glucose into two molecules of pyruvate. This process occurs in the cytoplasm and yields a small net gain of ATP and NADH through substrate-level phosphorylation. Its overarching purpose is to extract chemical energy by dismantling a larger, energy-rich molecule into smaller components, which is the defining characteristic of a catabolic process.B) Lipid synthesisLipid synthesis, such as the formation of triglycerides or phospholipids, assembles glycerol and fatty acid chains through dehydration synthesis reactions that form ester bonds. Building these long-chain hydrocarbons from acetyl-CoA precursors consumes substantial amounts of ATP and reducing equivalents like NADPH. The creation of these dense energy-storage molecules and membrane components from smaller subunits exemplifies constructive, anabolic metabolism.C) Protein degradationProtein degradation, whether via the ubiquitin-proteasome system or lysosomal autophagy, breaks down polypeptides into their constituent amino acids through hydrolysis of peptide bonds. This serves to remove damaged proteins, regulate cellular processes, and provide amino acids during nutrient scarcity. Degradation involves the dismantling of complex structures, which is the opposite of biosynthesis and is therefore a catabolic process.D) Oxidative phosphorylationOxidative phosphorylation is the final stage of aerobic cellular respiration and is fundamentally catabolic in its overall context. While it involves building a proton gradient, its primary function is to harvest the energy stored in electron carriers (NADH and FADH₂) that were generated from the catabolic breakdown of fuels like sugars and fats. The energy released is used to drive ATP synthesis, making it the energy-yielding phase of catabolism.Conclusion:Anabolic pathways build complex molecules and require energy input. Lipid synthesis clearly fits this definition, assembling large molecules from simpler precursors. In contrast, glycolysis, protein degradation, and oxidative phosphorylation are processes centered on breaking down molecules to release energy or recycle components, placing them firmly in the catabolic domain.

Which process is anabolic?

A
Glycolysis

B
Lipid synthesis

C
Protein degradation

D
Oxidative phosphorylation

Lipid synthesis is a biosynthetic process that builds complex molecules from simpler ones, which defines anabolism.

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Related Questions

Which process is anabolic?

A Glycolysis B Lipid synthesis C Protein degradation D Oxidative phosphorylation

Lipid synthesis is a biosynthetic process that builds complex molecules from simpler ones, which defines anabolism.

Topic Flashcards

Mini Quiz

Related Questions

A
Glycolysis

B
Lipid synthesis

C
Protein degradation

D
Oxidative phosphorylation