Friday, January 26, 2007
Analogy of The Animal Cell
1A) I'm comparing the animal cell to a restaurant.
The administrative office stores important information such as recipes of food and investment plans of the restaurant. It performs daily supervision of the operation of the restaurant so that it can function properly. Other than that, it decides when to expand the restaurant or when to set up a branch (Like the division of a cell). The Administrative office is the place where the manager works. He is in charge of employing and training chefs. The chefs are supposed to cook delicious foods (proteins) for the customers. The waiters put the food on trays, which are then placed on special carts. They will either be served to the customers or be sent them to the packaging department. In the packaging department, the workers pack the foods into containers for easier delivery. In order to deliver the food to the customers, the deliverymen have to pass through the security guards that guard the door and ensure that no troublemakers are allowed into the restaurant. Throughout the day, the cleaners will throw away all the rubbish and unwanted stuff left behind by the customers. The power supply provided all the energy needed in the restaurant, just like the mitochondria in the cell.
Controls all the activities of the cell & essential for cell Division-- administrative office
Produces Ribosomes -- Manager
Produces Proteins that is used inside/outside the cell-- Chefs
Rough endoplasmic Reticulum:
Transports the proteins made by the Ribosomes to the Golgi apparatus-- Waiter
stores and modifies the substances made by the ER & packages them into vesicles for secretion out of the cell-- Packaging Department
Vesicles that contain digestive enzymes &Break down engulfed bacteria/virus and worn out organelles -- Cleaners
a partially permeable membrane that only allows some substances to pass through and not others-- Security Guards
Performs aerobic respiration-- Power Supply
B) What are the advantages and disadvantages of animal cells only having a cell membrane (Compared to a cell wall found in plants)?
Advantages: Without the Cell Walls, we can move our bodies freely without feeling constricted, unlike plants which have to be rooted stiff to one place. The flexibility of the cell makes it easy to contract or expand easily to make very complicated and delicate movements ( such as a simple smile).
Disadvantages: Without a cell wall, the cell is too soft to keep in shape. Animals need special structure, like the skeletal system or exoskeleton , to support their bodies. When the water potential outside a cell is higher than the inside, Osmosis will occur. Unlike the plant cell, the animal cell does not have the cell wall to support and protect them, thus it will swell and even burst. Also, if the water potential outside is lower, the animal cell crenates when it becomes dehydrated and will eventually die, while the plant cell will just be plasmolysed.
Without the protection of the cell wall, animal cells are easier to be destroyed or injured.