The phrase "alter the portion" is correct and usable in written English.
It can be used when discussing changes to a specific part or segment of something, such as a document, recipe, or project.
Example: "To improve the overall quality of the report, we need to alter the portion that discusses the methodology."
Alternatives: "modify the section" or "change the part".
Property owners often grouse about having to seek approval from the city Landmarks Preservation Commission to alter the portion of their buildings designated as landmarks.
This study suggests a simple dietary strategy, decreasing food-item size without having to alter the portion size offered, may reduce energy intake at snacking occasions.
This is supported by a further study from Bikker et al., who showed that PEEP changes can alter the portion of lung tissue visualised by the EIT [ 22].
A-to-I editing can also result in the creation or elimination of splice sites, potentially altering the portions of the RNA that remain in the final product.
Through binding site competition, changes in the level of one family member can alter the relative portion of time each other family member occupies a specific location in the genome.
This study will help establish whether delivery of prognostic information, encouragement of advance directives, and sensitive discussion of terminal treatment options, can meaningfully alter the last portion of a patient's life.
The surface Lamé constants turns out to alter the ratio between the portion of membrane and bending energies.
Partitioning of the highly amphiphilic NSAID molecules into a membrane has the potential to significantly alter the polarity of some portions of the membrane and hence immiscibility of lipids in the bilayer, and so influence membrane phase behavior and phase separation.
Eliminating the feedback to the statoreceptors by severing its nerve between 31 36 h after landing did not alter the firing rate in proximal portion of the nerve in postflight snails, but it did so in control snails, leading these investigators to conclude that µG exposure might inactivate the efferent innervation of the statoreceptors.
Copy number variants (CNVs) are genomic variants that alter the diploid state of a portion of the genome, either by increasing (duplications, triplications) or decreasing (deletions) the number of alleles.
This might be because noradrenaline alters the portion of blood going to skin and muscle respectively.
