Rather than type out the explanation read the
Wikipedia entry hereWikipedia entry here
You should be aware that shutter speed is proportional to the aperture...ie. the greater the aperture (light admitted) the greater the shutter speed.
What the Wikipedia entry elucidates is that the f-stop in the light vs shitter speed vs aperture is a function of the ratio between the focal length and the physical aperture size. Therefore, for a given focal length if the aperture diameter increases then the f/stop reduces and you can use a faster shutter. i.e. going from 58mm to 77mm increases the aperture, reduces the f/stop and increases maximum possible shutter speed that you can use (assuming constant ISO and focal length).
Once you are comfortable with that concept considering finding out:
1/ How varying the aperture diameter changes the depth of field (including the impact of crop factor on the calculations).
2/ How varying the aperture of the lens affects sharpness - lens aberations at the wide open position and diffraction when it is stopped down.
If you search the forum there is plenty of discussion on both subjects (ad nauseum to many people who have been here before and probably ranks up there with how many angels can you get to dance on the head of a pixel before the noise of the disco drowns them out?).
There is plenty of discussion on the forum