MikroTik

My knowledge is very limited. I am setting up an RB450G v6.7. I wanted the following;
port 1 WAN static IP 1.1.1.1
port 2 LAN IP 2.2.2.2/24
port 3 (port 2 master and use this port for access to 2.2.2.2/24
port 4 LAN IP 3.3.3.3/24
port 5 (port 4 master and use the port for access to 3.3.3.3/24

It will only accept one master port, so I can't make port 4 the master of port 5. Port 2 is already the master of port 3. Do I bridge port 4 and 5 and how is that done?
I will be connecting an AP to port 2 and one to port 4. I don't have to use 2 subnets. I just thought it would be more efficient for the AP's. Any comments? The AP's are secure presently feeding 21 CPE's and 10 CPE's with static IP's (no devices like computers or phones).

Thanks
Bob

For create the bridge is just.

Thanks for the reply. I decided to stay with one subnet for both AP's and at a later date maybe move to two subnets. I will be installing the RB450G tomorrow and don't what to make any changes at this time.