• Methods of Nucleic Acid and Protein Sequencing:
• DNA Sequencing Methods:
• Maxam-Gilbert Method: Chemical cleavage method using dimethyl sulfate and hydrazine.
• Sanger Sequencing: Dideoxy chain termination method.
• Pyrosequencing: Sequencing-by-synthesis based on detection of released pyrophosphate ($PPi$).
• Illumina (Solexa): Next-generation reversible dye-terminator sequencing.
• Edman Degradation: A classic biochemical method for sequencing amino acids in a peptide/protein from the N-terminus, using phenylisothiocyanate (PITC). It is NOT a DNA sequencing method.
• nalysis:
• (Edman degradation): Correct (it sequences proteins, not DNA).

Correct option: (1) Edaman degradation

• Peroxisomal Fatty Acid $\beta$-Oxidation:
• Very long-chain fatty acids (VLCFAs, $\ge C_{22}$) and branched-chain fatty acids cannot be directly oxidized by mitochondrial enzymes; they undergo initial chain-shortening in peroxisomes.
• Acyl-CoA Oxidase (ACOX) is the rate-limiting first enzyme in peroxisomal $\beta$-oxidation.
• It catalyzes the desaturation of fatty acyl-CoA to trans-2-enoyl-CoA, transferring electrons directly to molecular oxygen ($O_2$) to generate hydrogen peroxide ($H_2O_2$), which is subsequently degraded by catalase.
• nalysis:
• (Peroxisome): Correct.
• (Mitochondria): The first enzyme in mitochondrial $\beta$-oxidation is acyl-CoA dehydrogenase, which transfers electrons to FAD/ETC, not oxygen.

Correct option: (4) Peroxisome

• Lipid and Cholesterol Homeostasis:
• SREBPs (Sterol Regulatory Element-Binding Proteins) are membrane-bound basic helix-loop-helix transcription factors that govern cellular lipid, fatty acid, and cholesterol biosynthesis.
• Regulation by Low Cholesterol:
• Under low intracellular cholesterol levels, SCAP (SREBP Cleavage-Activating Protein) escorts SREBP from the endoplasmic reticulum to the Golgi apparatus.
• In the Golgi, site-1 and site-2 proteases (S1P and S2P) cleave SREBP, releasing its active N-terminal domain to the nucleus, where it induces transcription of HMG-CoA reductase and LDL receptor genes.
• nalysis:
• (SREBP): Correct.
• (PPAR): Activated by fatty acids and eicosanoids.
• (LXR): Activated by oxysterols (excess cholesterol metabolites).
• (FXR): Nuclear receptor activated by bile acids.

Correct option: (3) SREBP