In castle you need some sort of passage way leading to your entrance. This passage way is mostly smooth. Like smooth ER they both have to have passage way to direct the person.
Rough ER to Outside of a wall
These rough walls in the castle will guide you and help you get out of trouble. They will do this by telling you when you need to stop walking.
Link to the picture : http://www.nomadickevin.com/wp-content/uploads/2014/11/Neuschwanstein011.jpg
Vacuoles to Castle Treasury
This is a place where both plant cell and castle have to store something important. In a castle money would definitely be stored in the castles treasury. This treasure in the long run would be very help for keeping the castle wealthy.
Link to the picture : http://previews.123rf.com/images/backyardproduction/backyardproduction1303/backyardproduction130300155/18662715-Stacks-of-gold-eagle-one-troy-ounce-golden-coins-from-US-Treasury-mint-in-old-carved-pirate-treasure-Stock-Photo.jpg
Cytoskeleton to The Mortar
Mortar something that holds stone or bricks together. This is very similar cytoskeleton because they both hold together or try to maintain its shape/from. Without mortar the whole castle would be losing its shape.
Link to the picture : https://upload.wikimedia.org/wikipedia/commons/8/88/Mortar_mixed_inside_bucket.jpg
Cell wall to the wall surrounding the castle
The cell wall is very similar to the castle wall. They both defend there area. The castle has a very tall wall made of stone surrounding the castle. If the castle is under attack by enemies the wall will defend the castle. For example a catapult will defend the castle by throwing boulders at the enemies.
Link to the picture : http://i0.wp.com/twosmallpotatoes.com/wp-content/uploads/2015/07/2015-07-11-102-Neuschwanstein-Castle-Germany.jpg
Cell Membrane to Entrance
The castle has a very large entrance. This is the main entrance that is made of very thick wood. This entrance has a very big role in protecting the people inside from the enemies outside. This also controls who came come in or who goes out. The entrance is very similar to the cell membrane.
Link to the picture : https://s-media-cache-ak0.pinimg.com/236x/5f/cb/0e/5fcb0e5623e3497fd32be59a7cb48578.jpg
