Hello, my name is Kaeleigh, and welcome to Animal Cell. In this video, you'll
learn all the parts that make up an animal cell and their function. Let's get started.
This is the diagram of an animal cell. Cells are microscopic particles that
are the building blocks of life. Cells are the smallest structure that contain all the basic
things necessary for life to even exist. Since cells are so important to life, there's a theory
all about them. Cell theory tells us that every organism or living thing is made up of cells.
Some very tiny living things only need one cell, and that is all of the things necessary
for life to exist happen inside the cell. And lastly, all cells come from pre-existing cells.
This means that each cell will divide in two at some point in its life.
Now I'm going to introduce each tiny part of the animal cell. These different parts
of the cell are called organelles. There are a lot of big words and new words in this video,
so it might be helpful to take notes in your science notebook to help you study later.
You can pause the video here to grab your note-taking supplies.
We will start from the outside and work our way in. The gray sac holding the cell
is the plasma or cell membrane. Each type of cell has a membrane that acts like the skin
of the cell. It keeps the inside of the cell safe from the outside of the cell
and only allows some materials to enter the cell. If the plasma membrane acts as the cell's
skin, then the thin green rods act as the cell's skeleton. These are called microtubules. They
provide the shape of the cell and hold the organelles in place. The red T is called a
centrosome, and is made up of two perpendicular centrioles. Each centriole is made up of 27
microtubules in a special shape. Centrioles are the most important in cell division.
The orange chains just beneath the cell membrane are called microfilaments. They act as the
skeleton of the cell also, and they help the cell keep its shape and allow the cell to move,
especially in muscle cells. The microfilaments allow muscles to contract when you flex.
This is called cytoplasm. Every type of cell has cytoplasm. The cytoplasm acts as the
security system of the cell and surrounds and holds the other organelles in place,
and it pushes out on the cell membrane so the cell can keep its shape.
The small gray dots floating in the cytoplasm are called ribosomes. Each type of cell has ribosomes.
They're known as the handymen of the cell. They create specific proteins
that are used to repair other parts of the cell.
The big red ball is called the nucleus and is the biggest organelle in the cell.
The nucleus carries the majority of the cell's DNA. DNA is the genetic information of the cell
and it tells the cell what kind it should be and when it will divide. In this way, the nucleus is
like the brain of the cell and controls the growth and the multiplication of the cell.
The dark red ring inside the nucleus is called the nuclear envelope,
and it separates the contents of the nucleus from the cytoplasm.
There's dark red dots on the nuclear envelope that allow materials
like proteins to move between the cytoplasm and the nucleus. They act
like a ticket booth and only allow certain materials into the nucleus at certain times.
The egg yolk in the middle of the nucleus is called the nucleolus.
The nucleolus has a main job of building ribosomes for the cell. After the ribosomes are built,
they are transported out into the cytoplasm to work as the handyman for the cell.
The light red material that surrounds the nucleolus and fills up the inside of the
nuclear envelope is called nucleoplasm. Its job is similar to cytoplasm,
but it always stays inside the nuclear envelope.
The orange and blue smiles are mitochondria, which are famously called the powerhouse of the cell.
They are called the powerhouse of the cell because they turn organic material
into energy for the cell, and this is the energy that helps the cell move and divide.
If a cell needs a lot of energy, like a muscle cell, it will have lots of mitochondrion. But
cells that need little energy to survive will have less. Reticulum. The first one
we will talk about is the small purple one, called the smooth endoplasmic reticulum. It
is used to metabolize lipids in the cell and help the cell detox from unwanted materials.
The other endoplasmic reticulum is called the rough endoplasmic reticulum. It is rough
because it is covered with bumpy ribosomes, and these ribosomes make specific proteins that are
then transported in small sacks called vesicles. The red bumps on the cell are the vesicles. They
are transport vehicles that move proteins and other materials between locations in the cells.
The green blob is the golgi apparatus. It is called the post office of the cell. It modifies,
sorts, and packages different materials to leave the cell or to be used within the cell.
The golgi apparatus receives proteins delivered by vesicles from the rough endoplasmic reticulum.
The orange halves in the cytoplasm are called lysomes. Lysosomes are a type of vesicle formed
by the golgi apparatus. Lysosomes have a powerful enzyme that break down harmful cell material and
waste and transport it out of the cell. Lysosomes can also break down cells that are ready to die.
That was a lot of new information. You now have a better understanding of each
organelle's job in an animal cell. Study your notes and practice what you learned
with one of the online games and the quizzes. Have fun, and remember to always be clever.