What does it mean when a bank is "fully loaned up"? Please briefly explain the situation when a bank is "fully loaned up".
The reserve requirement on deposits ensures that (for a given $reserve\ requirement(\%)$ and $deposits(\$)$): $$loans(\$) \leq deposits(\$)  \cdot (1 - reserve\ requirement(\%))$$
Fully loaned up means that this holds with equality: 
$$ loans(\$) =  deposits(\$)  \cdot (1 - reserve\ requirement(\%)) $$