Cell City Project

Animal Cell Compared To a Car

Cole Brownsberger

Luke Patterson

1. Cell Membrane and Exterior of the Car Page 1

The structure of a cell membrane has a phospholipid bilayer with proteins,

carbohydrates, and other lipids embedded. The phospholipid bilayer consists of two layers that

face each. Each layer has an outside polar, hydrophilic, glycerol head, that can come into

contact with water, whereas the inside of the layer has a fatty acid tail that cannot come into

contact with water because it is hydrophobic and non-polar. Cholesterol is found in between

closely related phospholipids. Integral proteins are embedded into the membrane and they

stick out both sides and Peripheral proteins are only embedded into one side of the cell

membrane. Glycoproteins are carbohydrates attached to membrane proteins or lipids and can

be found on the extracellular surface only. The extracellular matrix is referred to as the “face”

of the cell or the extracellular surface. It is composed of all the cell membrane parts and is also

different for each type of cell.

The structure of a cell membrane is composed of a lot of organelles, but what is the

function of these parts? Well, the phospholipid bilayer provides the overall support, shape, and

protection for the cell. The cholesterol found in between the phospholipids helps increase

stability by preventing the phospholipids from being too fluid. The integral proteins act as

regulatory channels for membrane transport, and the peripheral proteins provide support

because they attach to the cytoskeleton of the cell. The peripheral proteins can also act as

enzymes and also receptor sites for channels. The glycolipids are part of the cell to cell adhesion

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(tissue integrity), and cell to cell recognition and communication. The extracellular matrix helps

identify the cell and it also interacts with neighboring cells to communicate.

The cell membrane is an important part of the cell because it provides the shape and

protection for the cell, as well as give it support. That is why the exterior of a car is just like the

cell membrane of a cell. The exterior of a car gives a car its shape and support, and it also

protects everything inside it. The integral proteins of the exterior of a car would be the doors,

windows, and grille. Each car has a different type of exterior and the outside frame of a car

helps identify what kind it is just like the extracellular matrix does a cell. The peripheral proteins

attach to the axis of a car just like they attach to the cytoskeleton of a cell. The phospholipid

bilayer of a car is the actual exterior itself. The outside layer is hydrophilic and can come into

contact with water like the outside layer of a phospholipid in a cell. The cell membrane is one of

the most important parts of a cell, and the exterior of a car is very important to the car itself.

2. Nucleus and Driver Page 3

The Nucleus is generally the large, central part of the cell. There is only one nucleus in a

cell. The nucleus is surrounded by a nuclear envelope and membrane. It is also composed of

nuclear sap found in the nucleoplasm, and has a nuclear matrix that provides the support to the

nucleus. Chromatin is found inside the nucleus and the chromatin contains DNA. The nucleolus

is also found inside the nucleus and so is RNA.

The Nucleus is the central control room that protects the genetic material. The DNA

found in chromatin is too large to leave the nucleus, so the nucleus has to protect it. The

nucleus uses the DNA as a blueprint on how to build and operate all the cell parts. Without it,

the cell membrane would not be able to function properly.

The importance of the nucleus of the cell is just like the driver of a car. The driver’s brain

is just like a cell’s DNA because the driver contains all of the knowledge of how to control and

operate the car, and without him, the car would not be able to function properly. The driver is

the central control room of a car, and there can only be one driver just like there can only be

one nucleus in a cell.

3. Nucleolus and the Driver’s Head Page 4

The nucleolus is the area containing RNA and proteins. It is not membrane bound so it

is really just a more dense part of the nucleus. It does not take up the whole part of a nucleus

but it does take up about a fourth of space.

The nucleolus function is to produce ribosomes. The ribosomes function is to produce

proteins so that whole process starts in the nucleolus. Using rRNA, the nucleolus builds these

ribosomes and then ships them out of the nucleus.

The nucleolus of a car would be the head of the driver. The driver sees and hears his

surroundings and has to make decisions based on his senses. He has to create thoughts and

send them down to his muscles so they can make reactions. An important part of the car is the

driver because he operates and controls it. The nucleolus is important in a nucleus, just like the

driver’s head is important to the driver and the car.

4. Chromatin and a Driver’s Brain Page 5

The chromatin of cell is found within the nucleus. Chromatin contains DNA that is bound

around histones and wrapped around protein. It is too big to leave the nucleus, and it is the

nucleus’s job to protect it. If all the DNA, found in the nucleus, was put together into one

strand, that strand would be almost six feet long. As you can tell, there is a lot of DNA in

chromatin.

Chromatin’s function in a cell is to provide genetic information on how to build and

operate all cell parts. One strand of DNA in chromatin has 46 unique parts that hold the

information on how operate the cell parts. Without chromatin in the nucleus, the cell would not

be able to function.

The brain of a driver is very similar to chromatin. The brain of a driver processes and

reacts to what the five senses of our body tell us. The brain can tell our body how to operate all

of our parts, just like the DNA in chromatin. The brain is also too big to leave the body, and

chromatin is too big to leave the nucleus.

5. Cytoplasm and the Interior of the Car Page 6

The cytoplasm is the region within the cell between the cell membrane and nuclear

membrane. The endoplasm is anything within the cytoplasm and the ectoplasm is anything

outside if the cytoplasm. The cytoplasm contains the organelles and parts within the cell.

Within the cytoplasm is cytosol, a clear liquid gel made up of water, ions, salts, organic

compounds, and pigments.

The function of the cytoplasm is to keep fluidity in the cell. Without the cytoplasm, the

organelles and parts would have a tough time staying in place because they would be

suspended in air. The cytoplasm is an area where the organelles and parts can move around or

stay in place.

The interior of a car and the cytoplasm of a cell are alike in many ways. The interior of a

car contains the parts within a car. The cytosol of a car would just be air. Air is a clear substance

that contains oxygen, minerals, and ions.

6. Mitochondria and Pistons of an Engine Page 7

The Mitochondria may have been its own cell at one point because of its structure. It

has an outer membrane that surrounds the organelle. An inner membrane called the cristae is

found inside the out membrane. The space between the outer membrane and the inner

membrane is known as the inter-membrane space. The mitochondria matrix is found within the

inner membrane, and also inside the inner membrane is DNA. The mitochondria’s DNA actually

came from the mother’s ovum, making the mitochondria have its own DNA.

The function of the mitochondria is cellular respiration, which produces ATP. ATP is the

energy for the cell. The mitochondria are also part of regulating a cell’s metabolism. Through

the process of producing ATP, they can speed up metabolism or if production is low, slow it

down. For the cell to have any energy, mitochondria will have to produce it.

The pistons of an engine in a car are very similar to the mitochondria in a cell. The

pistons produces energy for the car just like the mitochondria produces energy for the cell. An

engine uses gasoline in the combustion chamber to move the pistons up and down which in

return turns the axel of the car. When the pistons move up and down, the friction produces a

lot of heat and energy that the car parts can also use. Without the pistons of an engine, a car

would not be functional, like a cell without its mitochondria.

7. Golgi Complex and the Carburetor Page 8

The Golgi complex, also known as the Golgi apparatus, is a very complicated organelle. It

is a series of folded membranes found on the inside of a cell, and it looks like a stack of

pancakes. The actual folded parts of the membrane are called the cisternae. The Golgi complex

has three faces. The receiving part is called the “cis”, the enzymatic work area is called the

“medial”, and the shipping dock is called the “trans”. Proteins first go to the cis, then they go

through the cisternae until they enter the medial, and then they go out of the Golgi complex

through the trans.

The function of the Golgi complex is to modify, sort, store, and ship proteins and lipids.

The Golgi apparatus can receive proteins from the Rough ER, modify it, and then ship them to

other places in the cell like the vacuoles. The Golgi apparatus can also receive food outside the

cell, process it, and then send it to the smooth ER.

The carburetor in a car is a device that blends air and fuel so the internal combustion

engine can use it. The carburetor receives fuel from the fuel vapor hose, and it also receives air

from outside the car through the grille. The carburetor has to measure the airflow of the

engine, deliver the correct amount of fuel to keep the fuel/air mixture in the proper range so

the combustion chamber can safely use it (adjusting for factors such as temperature), and

finally it has to mix the air and fuel evenly. The carburetor has to do all of this very fast because

the combustion chamber uses up this mix quickly. The throttle valve is directly related to the

amount of airflow and fuel mix there is. If the driver increases the throttle, more air/fuel mix

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will be needed to supply the engine with. The Golgi apparatus does this in a cell by packaging,

and distributing the materials the cell needs.

8. Centriole and the Fuel Vapor Hose Page 10

A centriole is a cylinder-like cell structure that has a hollow middle. The walls of the

centriole are composed of nine triplets of microtubules. This means that there are nine sets

groups on the outside of the centriole with each group having three microtubules.

Microtubules are proteins of the cytoskeleton.

The function of the centriole is to help organize mitotic spindle to move chromosomes.

During mitosis, chromosomes are separated into two cells. Mitotic spindle occurs when

chromosomes are divided and placed into the two new cells. To help with this separation,

centrioles are used. Using the centrioles for support, chromosomes are able to be distributed.

The fuel vapor hose in a car is like the centriole in a variety of ways. They are both

hollow, allow things to pass through them fairly easily. The walls of both the fuel vapor hose

and the walls of a centriole, are made to be strong and sturdy. The fuel vapor hose distributes

fuel into the carburetor. Just like the centriole distributes chromosomes into the cells, the fuel

vapor hose distributes fuel into the carburetor.

9. Microtubules and Bumpers/ Fenders Page 11

Microtubules are the biggest protein filament out of the three types. They are part of

the cytoskeleton in the cell. Microtubules are thick, hollow tubes. The outside of these tubes

wrap around each other, but they still leave a hollow opening.

The function of the microtubules is to help with cell shape and support, cell mobility,

organelle movement and chromosome movement. As part of the cytoskeleton, microtubules

have a big part of cell shape and support. The wrapped around walls of the microtubules give

the part strong walls. As part of the chromosome movement, microtubules can be found in

centrioles. When they are in the centrioles, the microtubules are in sets of three and there are

nine of those sets. In all, there are 27 microtubules in a centriole and they help support and

shape that part.

Fenders and bumpers of a car are very much alike to the microtubules of a cell. The

bumpers of a car are the front and rear end parts that are supposed to absorb the impact of

head on or rear end collisions. The fenders of a car are the side parts that curve over the wheel.

These parts are like the microtubules of a cell because they help the “cell mobility” of car by

being aerodynamic. They also help the car with structure and support by absorbing impact in

collisions. By protecting the other parts of a car, these parts also help out with the “organelle

movement”. If the engine is not damaged in a wreck, the car can still be used, and its parts can

still work fine.

10. Vacuole and Fuel Tank Page 12

In an animal cell, vacuoles are smaller, more numerous, than the typical one large

vacuole in the plant cell. In aquatic organisms, some vacuoles can be contractile and they pump

out excess fluid from the cell. The vacuoles can have lysosome attached. The purpose of this

would be to easily transfer goods from one part to the other.

The function of a vacuole is to store things like water, salts, enzymes, food, and wastes;

to protect the cell by isolating chemicals and wastes; and to support the growth. Lysosomes can

give wastes to the vacuoles. The wastes that are harmful to the cell can also be temporarily

stored in the vacuoles as sort of a safe haven. With numerous vacuoles in a cell, food and

energy is readily available for the cell to use especially when it is growing and going through the

process of mitosis.

The fuel tank in a car is very similar to the vacuole of a cell. The fuel tank, more

commonly referred to as the “gas” tank, provides fuel for the engine. Fuel pumps pump fuel

into the gas tank where the fuel can be stored for use. Special valves and protection are needed

for the fuel tanks because the fuel going into them is highly flammable. When the engine is in

need of fuel, fuel from the gas tank is distributed between a hose that is connected from the

tank to the engine. Most fuel tanks are stored in front of the rear axle to keep them from being

damaged. If there is no fuel in the fuel tank, then the engine would not run. In a cell, if the

vacuoles have no stored energy, then the cell is going to have some problems. This could go the

same way though if the gas tank and the vacuole also have too many things stored in them.

11. Lysosome and Exhaust Page 13

Lysosomes are microbodies produced by the Golgi complex. The membrane of a

lysosome is filled with catabolic enzymes. They can be found in white blood cells. Lysosomes

can be referred to as your auto-immune disease. The interior of a lysosome is acidic, which

helps break down wastes and materials harmful to a cell.

The functions of a lysosome are one, to digest organic macromolecules, two, to destroy

invading bacteria and viruses, and three, recycle the wastes of the cell. Basically the lysosomes

are the clean-up crew of a cell. Through apoptosis, a cell will be programmed to die if

lysosomes cannot work fast enough to get rid of the excess materials in a cell.

One of the most important functions of the lysosome is to recycle the wastes of the cell.

The exhaust does exactly that but in a car. The exhaust of a car takes burnt gasses away from

the combustion chamber and the engine, and projects it away from the car using the exhaust

pipe. The burnt gasses are cooled down before they leave the engine system. This is why we

can see the gasses coming out of the tail pipe of the exhaust of a car. The gas coming out can

be lethal, and if left in the engine, can cause some serious damage. The lysosomes of a cell are

very important for sending away harmful materials, and so is the exhaust pipe of a cell.

12. Peroxisome and Catalytic Converter Page 14

Peroxisomes in a cell are single membrane bound and have enzymes inside of them. The

Peroxisome membrane contains metabolic enzymes that go through a lot of chemical reactions.

Peroxisome microbodies can be found abundant in the liver of an organism.

Peroxisome microbodies deal with catabolism, metabolism, and detoxification. The

catabolism of fatty acids is for energy for the cell. The metabolism of lipids also provides some

energy. The detoxification is found in liver cells. Catabolase and hydrogen peroxide are used for

the detox in liver cells to get rid of harmful wastes in the body.

The catabolic converter in a car works like the peroxisome microbodies in a cell. A

catabolic converter is an exhaust emission control device that converts toxic chemicals in the

exhaust of an internal combustion engine into substances that are less harmful for the

environment. Inside a catalytic converter, a catalyst stimulates a chemical reaction in which the

most harmful byproducts of the combustion in the engine are converted into less toxic

substances by means of catalyzed chemical reactions. Although materials harmful to the

environment still come out of this, the catabolic converter greatly reduces the amount of

harmful substances. Peroxisomes do just that in cells.

13. Microfilament and Transmission Page 15

Microfilaments, also known as actin filaments, are the smallest of the protein-filament

types. Microfilaments are part of the cytoskeleton organelle. They are composed of the protein

“actin”. The shape of the microfilaments is actually composed of two thin, solid, intertwined

filaments. This gives the structure more support, and makes the sides denser.

The function of microfilaments is to help with cell shape and support, cell division, cell

mobility, and muscle contraction. As part of the cytoskeleton of a cell, microfilaments main

function is the cell shape and support. During cell division, microfilaments help separate two

cells from the existing one. In muscle contraction, microfilaments are either relaxed, or flexed.

The “muscle” of a car is its transmission. The transmission gears of a car control the

amount of power used in an engine. The transmission of a car controls the direction, and the

flow of fuel in the combustion chamber. The gears represent how much torque is added to the

engine. Microfilaments do the same thing in a cell. Tissue in the muscle is full of microfilaments

and they help with the power of the muscle just like the transmission of a car helps with the

power of the engine.

14. Ribosome and Grille Page 16

Ribosomes are numerous, small, cellular structures that are not organelles. They are

also not membrane bound. They are built in the nucleolus and are made of rRNA and proteins.

Ribosomes are composed of two subunits, either large or small. Ribosomes are found “free” in

cytosol, meaning they are just floating around, or they are “attached” to an endoplasmic

reticulum.

Ribosomes are a big part in protein synthesis. They free build proteins for use within the

cell. The attached proteins are then exported and sent out of the cell. Proteins play a big role in

the cell and they have many uses. The production of the ribosomes is critical for the use of

proteins.

The grille of a car plays a significant role. It is a major cooling component for the car’s

engine. It also protects the radiator and the engine. The grille of a car also intakes air, an

important substance for the engine and cooling system. The ribosomes of a cell produce

proteins that are vital to the cell. Well air is also vital to a car, and the grille transports it into

the engine.

15. Rough Endoplasmic Reticulum and the Air Conditioning System Page 17

The endoplasmic reticulum is an internal, folded membrane system. It contains inner

folds called cisternae, which increase the surface area within the organelle. There are two types

of the endoplasmic reticulum; the smooth ER and the rough ER. The rough ER has attached

ribosomes found on the surface. The surface with ribosomes is continuous with the nuclear

envelope.

The function of the rough endoplasmic reticulum is for the completion of protein

synthesis. It produces the final product of the protein itself. The rough ER uses the ribosomes

attached to it to help produce the proteins. After the proteins are made, the rough ER then

sends them to the Golgi complex to be packaged and then later, shipped away.

The air conditioning system of a car works just like the rough endoplasmic reticulum.

Using air from the car, the air conditioning uses power from the engine to cool down or heat up

the air that has passed through the engine. This creates a circuit of heating and cooling the car.

The system then pushes the cooled or heated air though vents and onto the passengers to

make their car ride more enjoyable. The rough endoplasmic reticulum works this way by

receiving proteins, and sending them to the Golgi complex to help the cell.

16. Smooth Endoplasmic Reticulum and the Muffler Page 18

The smooth endoplasmic reticulum has no ribosomes on the surface, unlike the smooth

endoplasmic reticulum. It consists of tubules and vesicles that branch out to form a network of

interconnected passageways in which the food received can travel through.

There are many functions of the smooth ER. One would be lipid synthesis, which is basically the

process of making lipids. Another function is carbohydrate metabolism. During carbohydrate

metabolism, the smooth ER breaks down carbohydrates and can use them for energy or send them

along through the tubules and vesicles. The smooth ER in muscle cells can also store calcium. One of the

other functions of the smooth ER is detoxification in liver cells. The actual detoxification takes place in

the smooth ER as particles move through the tubules and vesicles.

The smooth endoplasmic reticulum is relatively the same thing as a muffler in a car. The muffler

of a car is part of the exhaust system. Like the smooth ER in the liver cells, detoxification happens to go

through the muffler. Gasses used by the engine pass through the muffler to then enter the outside air.

Most of the engine’s noise also passes through the exhaust system. The muffler has lining in the pipes to

cancel out the sound waves and create wave interference. In a sense, the muffler is breaking down the

sound wave, like the smooth ER breaks down carbohydrates.

17. Cilia and the Wheels Page 19

The cilia of a cell are small, numerous hair-like extensions of the cell membrane. Each

cilia hair has a microtubule arrangement of nine sets of two microtubules. These sets form a

cylinder around the outside of a cilia hair, and on the inside of the cilia are two more

microtubules. This gives the cilia structure and strength.

The function of the cilia is to transport the cell. Thousands of cilia move the cell across

the surface. Working together, the cilia move like tank wheels move. It is not the “one step

front of the other” type of movement. The cilia move effectively and are able to move the cell.

Tires of a car work exactly like cilia. The treads and grooves of a car give the car traction.

The rolling motion of the tires enables the car to move, just like the cilia’s roll over action to

move a cell. The bearing inside of the tire are like the microtubules in cilia, they give support

and strength to the car.