The phrase "act as second" is correct and usable in written English.
It can be used in contexts where someone is taking on a supportive or secondary role, often in a competitive or collaborative situation.
Example: "In the debate, I will act as second to my partner, providing additional arguments and support."
Alternatives: "serve as a backup" or "function as a supporter".
Inositol pyrophosphates have been linked to a wide range of cellular functions, and there is growing evidence that they act as second messengers.
The fatty acids produced by hydrolysis of the phospholipids act as second messengers to signal the cell that more lipopolysaccharide is needed.
These data drive us to speculate that GD3 might act as second messenger in the activatory cascade, which leads to CD32 expression and triggers platelet adhesion and spreading to the subendothelial matrix.
Although consumers have been far from enthusiastic about smartwatches that act as second screens for our smartphones, fitness wearables have been adopted enthusiastically and Apple is expected to capitalised on this.
Andy Serkis treated the 6,500 attendees to a couple of foul-mouthed lines from Gollum and spoke passionately about his love for the work and how glad he was when Jackson asked him to act as second unit director.
While for trialkylaluminum and diethylaluminum alkoxide the number of PS chains formed can be related directly to the initial amount of lithium initiator, for diisobutyl aluminum hydride and diisobutylpolystyryl aluminum, the hydride and polystyryl groups act as second chain carrier, thus yielding the formation of up to two polymer chains per 'ate' complex.
As such, ILCs can act as first-line defenders in the context of infection, inflammation and cancer.
The fans, on a consistent basis, act as third commentator so you can allow the game to breathe because of the fans".
Tests act as first clients to the classes' API.
Act as first contact for customer service in the office of recreation.
These techniques may act as first-line therapies in certain pathological entities or as attractive adjuncts to conservative therapy, radiotherapy or surgery in other cases.
