Simplistically, molecules diffuse through the cytoplasm because of their random motion. The rate of diffusion is affected by the viscosity of the cytoplasm and by the size and shape of the molecule. Since the dimensions of most cells are quite small, it does not take long for freely diffusing molecules to encounter their binding partners. Specialized transport systems exist to transport molecules over long distances, such as in the axons of neurons.

You should look for literature on the diffusion coefficients of biological molecules in cells. Here are a few articles:

http://book.bionumbers.org/what-are-the-time-scales-for-diffusion-in-cells/

Article Determination of diffusion coefficients in live cells using ...

Article In vivo single-RNA tracking shows that most tRNA diffuses fr...

https://www.nature.com/articles/s41589-018-0063-y

try searching with some key words: tRNA, localization, tracking, translation

don't discount the interactome studies, usually there is a scaffold of proteins that allow different molecules to come into closer contact so molecules don't have to travel far to get to where they need to what they need

Simplistically, molecules diffuse through the cytoplasm because of their random motion. The rate of diffusion is affected by the viscosity of the cytoplasm and by the size and shape of the molecule. Since the dimensions of most cells are quite small, it does not take long for freely diffusing molecules to encounter their binding partners. Specialized transport systems exist to transport molecules over long distances, such as in the axons of neurons.

You should look for literature on the diffusion coefficients of biological molecules in cells. Here are a few articles:

http://book.bionumbers.org/what-are-the-time-scales-for-diffusion-in-cells/

Article Determination of diffusion coefficients in live cells using ...

Following

thanks for response, let me read them and if i still got questions i would be thankful if you response again.

Actually, a t-RNA randomly bumping into an amino acid does not result in the loading the amino acid onto the t-RNA, you also need a family of enzymes called t-RNA synthases which catalyze the ATP-dependent formation of a covalent bond between the t-RNA and the amino acid.

t-RNA synthases catalyze the formation of a covalent bond between the amino acid and bound ATP, releasing pyrophosphate. In a next step, the t-RNA is bound to the synthase, the amino acid is transferred from the nucleotide to the t-RNA and the reaction products AMP and AA-t-RNA are released.(

Article Aminoacyl-tRNA synthetases: Structure, function, and drug discovery

). The t-RNA synthases are responsible for the correct pairing of amino acids with the corresponding t-RNAs, therefore the genetic code is a function of t-RNA synthase specificity.

In eukaryotic cells, t-RNA is produced in the nucleus, and its transport through the nuclear pore is dependent on specific transport proteins (Article Coordination of tRNA nuclear export with processing of tRNA

Article Review: Transport of tRNA out of the Nucleus—Direct Channeli...

yes, of course there are more enzymes, proteins, also metabolites etc. just wanted to simplify my question.

and after all my research and readings, i just figured out that an electrostatic field that named solvation shell helps molecules find their way to destinations. it is wonderful mechanism, more distant from molecule less pull force, so some of proteins had to approach to the active sites in a certain positions.

i suggest you search about it. I think is interesting issue.

Best regards to all who responded. love this community.