Sure gets worried and in a flap when one gets angry (6,2)
I believe the answer is:
flares up
'one gets angry' is the definition.
(I've seen this in another clue)
'sure gets worried and in a flap' is the wordplay.
I cannot really see how this works, but
an anagram of 'sure' is 'resu' which is present in the answer.
'a' is present in the answer.
This explanation may well be incorrect...
'when' acts as a link.
Can you help me to learn more?
(Other definitions for flares up that I've seen before include "when signs of distress are seen?" , "gets angry" .)