Keyword based literature search
I think the statement above is slightly misleading. There are many many types of cell signalling, anything from RTK (at the cell surface or when its endocytosed), to steroid receptors, which operate on different time scales and produce different results depending on the type of signalling. Also it depends on what you are measuring/defining as a signal/response in lets say "cell signalling" because you could define cell signalling response as protein phosphorylation at any point in a signalling cascade or it could be the transcriptional activation itself (consider the MAPK pathway in Drosophila, at which point do you consider a response is produced? when Raf is activated? or when transcription factors such as pointed bind to their ETS binding site and start to transcribe as measured by luciferase? as you can tell the time difference between the two is quite large, well as far as I know after RTK activation in Drosophila it takes ERK 20 minutes just to translocate to the nucleus). A cell signalling response could also constitute changes in the rate of cell migration, cell shape etc, which can either be slow or fast depending on the signal in question. so I think the above question needs major rethinking and redefining.

Now getting back to your questions about key search terms, in my experience, over time you just end up developing a knack for what you consider to be key words after you carefully define the question and think bout its different aspects. A rule of thumb that I use is typing at name of proteins (e.g. JNK or RAS etc) or processes (transcription, phosphorylation etc) and use a word like rate, time-scale, half-life, turn-over or something like that if its measuring changes in time you are interested in. Just play around with words.

Also as a general advice you don't have to reference every snippet of every fact like "water is liquid at RT in standard atmospheric pressure" etc. References are meant to be there to acknowledge the work of others like "how DNA was discovered" so that people can't just lift paragraphs or pages out os someones research without acknowledging them and passing it as their own work.

Hope this helps.