Anabolic and Catabolic Reactions
- Metabolism is the sum of all chemical reactions in an organism, divided into two categories:
- Anabolic reactions: Build larger molecules from smaller ones, requiring energy.
- Catabolic reactions: Break down larger molecules into smaller ones, releasing energy.
Anabolic Reactions: Building Up
Definition
Anabolic Reactions
Anabolic reactions are metabolic processes in which smaller molecules are built into larger, more complex molecules using energy.
- Anabolic reactions create complex molecules from simpler ones, requiring energy input.
- These reactions are often condensation reactions, where water is a byproduct.
- Below are some examples of anabolic reactions;
Protein Synthesis
- Amino acids are linked together by ribosomes to form polypeptides.
- This process occurs through condensation reactions, where a water molecule is released for each peptide bond formed.
- The polypeptides fold into functional proteins, essential for cellular structure and function.
- Insulin, a protein hormone, is synthesized by linking amino acids in a specific sequence.
- This process is critical for regulating blood sugar levels.
Glycogen Formation
- Glycogen is a polysaccharide stored in liver and muscle cells.
- It is formed by linking glucose molecules through condensation reactions.
- Enzymes like glycogen synthase catalyze the formation of α-1,4 and α-1,6 glycosidic bonds, creating a branched structure.
- After a meal, excess glucose is converted into glycogen for storage.
- This process ensures a readily available energy source during fasting or exercise.
Photosynthesis
- Photosynthesis is an anabolic process where plants, algae, and some bacteria convert carbon dioxide and water into glucose and oxygen.
- This process occurs in the chloroplasts and requires light energy, which is captured by chlorophyll.
- The light-dependent reactions produce ATP and NADPH, which are used in the Calvin cycle to synthesize glucose.
Remember, anabolic reactions require energy, often in the form of ATP or light (as in photosynthesis).
