[Tkinter] Control the application using the keyboard

[Christina]

Hello,
I have a problem with key control in my tkinter app. After pressing the key ("Enter", →, ←, +, Ctrl+S) I want to do my function. How do I set this control after pressing these keys? For example here is the scheme of the program (not my app):

from tkinter import*
app = Tk()

def MyFunction(x):   #I want to do this after pressing "Enter"
    print(x)

def MyFunction2(y):   #I want to do this after pressing "→"
    y = y + 1
    return y

def MyFunction3(z):   #I want to do this after pressing "Ctrl+S"
    return z**2

def MyFunction4(a):   #I want to do this after pressing "+"
    print(z*2)

app.mainloop()