You are at the vacuole (VAC) of the cell.
Vacuoles are storage bubbles found in cells. They are found in both animal and plant cells but are much
smaller in animal cells. Vacuoles might store food or any variety of nutrients a cell might need to survive.
They can even store waste products so the rest of the cell is protected from contamination. Eventually,
those waste products would be sent out of the cell.
The structure of vacuoles is fairly simple. There is a membrane that surrounds a mass of fluid. In that
fluid are nutrients or waste products. Plants may also use vacuoles to store water. Those tiny water bags
help to support the plant. They are closely related to objects called vesicles that are found throughout
the cell.
The vacuole holds large amounts of water or food. Don't forget that vacuoles can also hold the plant
waste products. Those waste products are slowly broken into small pieces that cannot hurt the cell.
Vacuoles hold onto things that the cell might need, just like a backpack.
You are at the nucleus of the cell.
The cell nucleus acts as the “control center” of the cell. If your cell was a city, then it would be like the
town hall or the government. If it happens in a cell, chances are the nucleus knows about it!
The nucleus is not always in the center of the cell, but it is usually somewhere in the middle of the
cytoplasm. You probably won’t find it near the edge of a cell because that might be a dangerous place
for the nucleus to be.
Not every cell has a nucleus. In fact, only eukaryotic cells do. Prokaryotes, like bacteria, don’t have a
nucleus. The nuclear envelope (NE) surrounds the nucleus and all of its contents. This is similar to the
cell membrane around the whole cell. There are also pores and spaces for RNA and proteins to pass
through while the nuclear envelope keeps all of the DNA inside. Oh, and right in the center of the
nucleus is the nucleolus (N), where all the ribosomes are made!
You are at the rough endoplasmic reticulum (RER).
While the function of the nucleus is to act as the cell’s “control center”, the endoplasmic reticulum
functions as the manufacturing and packaging center. It works closes with the Golgi apparatus and
ribosomes.
The endoplasmic reticulum is a network of membranes found throughout the cell and connected to the
nucleus. The membranes are slightly different from cell to cell and a cell’s function determines the size
and structure of the endoplasmic reticulum. Some cells, such as prokaryotes or red blood cells, do not
have an ER of any kind, but cells that synthesize and need a lot of proteins would need a large amount of
ER.
Here at the rough ER, you will find ribosomes attached to the surface, but over at the smooth ER, there
aren’t any. The double membranes of smooth and rough ER form sacs called cisternae. Here, protein
molecules are made and then sent off to the Golgi apparatus for additional packaging and distribution.
You are at the smooth endoplasmic reticulum (SER).
While the function of the nucleus is to act as the cell’s “control center”, the endoplasmic reticulum
functions as the manufacturing and packaging center. It works closes with the Golgi apparatus and
ribosomes.
The endoplasmic reticulum is a network of membranes found throughout the cell and connected to the
nucleus. The membranes are slightly different from cell to cell and a cell’s function determines the size
and structure of the endoplasmic reticulum. Some cells, such as prokaryotes or red blood cells, do not
have an ER of any kind, but cells that synthesize and need a lot of proteins would need a large amount of
ER.
Here at the smooth ER, you will not find any ribosomes attached to the surface like you do at the rough
ER. The smooth ER (SER) acts as a storage organelle. It is important in the creation and storage of lipids
(fats) and steroids used for many purposes in the plant cell.
You are at the golgi apparatus (G).
The Golgi apparatus or Golgi complex is found in most cells. It is another packaging organelle like the
endoplasmic reticulum. And while the layers of membranes may look like the ER, they serve a different
function. The Golgi apparatus gathers simple molecules and combines them into more complex
molecules. It then takes those big molecules, packages them in vesicles, and either stores them for later
use or sends them out of the cell.
It is also the organelle that builds lysosomes. Golgi complexes in the plant may also secrete complex
sugars and send them off in secretory vesicles by pinching them off the membrane. The membranes
also surround areas of fluid where the complex molecules (proteins, sugars, and enzymes) are stored
and changed.
You are at the mitochondria.
Mitochondria are known as the powerhouses of the cell. It uses sugar and oxygen to create energy in
the cell in a process called cellular respiration. Many of the reactions involved in cellular respiration
happen in the mitochondria. Mitochondria are the working organelles that keep the cell full of energy.
Mitochondria are small organelles floating free throughout the cell. Some cells have several thousand
mitochondria while others have none. Muscle cells need a lot of energy so they have loads of
mitochondria. Neurons (cells that transmit nerve impulses) don’t need as many. If a cell feels it is not
getting enough energy to survive, more mitochondria can be created. Sometimes a mitochondrion can
grow larger or combine with other mitochondria. It all depends on the needs of the cell.
Mitochondria are shaped perfectly to maximize their productivity. They are made of two folded
membranes which increases the surface area inside the organelle. Since many of the chemical reactions
happen on the inner membrane, the increased surface area creates more space for reactions to occur. If
you have more space to work, you can get more work done.
You are at one of the ribosomes.
Cells need to make proteins. Enzymes made of proteins are used to help speed up biological processes.
Other proteins support cell functions and are found embedded in membranes. Proteins even make up
most of your hair. When a cell needs to make proteins, it looks for ribosomes. Ribosomes are the
protein builders or the protein synthesizers of the cell. They are like construction guys who connect one
amino acid at a time and build long chains.
Ribosomes are special because they are found in both prokaryotes and eukaryotes. While a structure
such as a nucleus is only found in eukaryotes, every cell needs ribosomes to manufacture proteins. Since
there are no membrane-bound organelles in prokaryotes, the ribosomes float free in the cytosol.
Ribosomes are found in many places around a eukaryotic cell. You might find them floating in
the cytoplasm or attached to the endoplasmic reticulum. It looks bumpy under a microscope. The
attached ribosomes make proteins that will be used inside the cell and proteins made for export out of
the cell. There are also ribosomes attached to the nuclear envelope.
You are at the cell membrane.
According to cell theory, cells are the main unit of organization in biology. Whether you are a single cell
or a blue whale with trillions of cells, you are still made of cells. All cells are contained by a cell
membrane that keeps the pieces inside. When you think about a membrane, imagine it is like a big
plastic bag with some tiny holes. That bag holds all of the cell pieces and fluids inside the cell and keeps
any nasty things outside the cell. The holes are there to let some things move in and out of the cell.
The cell membrane is not a solid structure. It is made of millions of smaller molecules that create a
flexible and porous container.Proteins and phospholipids make up most of the membrane structure.
The phospholipids make the basic bag. The proteins are found around the holes and help move
molecules in and out of the cell. There are also proteins attached to the inner and outer surfaces of the
membrane.
Scientists use the fluid mosaic model to describe the organization of phospholipids and proteins. The
model shows you that phospholipid molecules are shaped with a head and a tail region. The head
section of the molecule likes water (hydrophilic) while the tail does not (hydrophobic). Because the tails
want to avoid water, they tend to stick to each other and let the heads face the watery (aqueous) areas
inside and outside of the cell. The two surfaces of molecules create the lipid bilayer.
You are at the lysosome.
The lysosome is a membrane-bound organelle found in animal cells. It uses enzymes to break down
(digest) food particles and to break down the cell when the cell dies.