Cell Parts and Functions Table
Cell Organelle
Cell Function
Nucleus
Directs all cell activities "Brain or Control Center of cell"
Nuclear Envelope (Membrane)
Controls what passes in and out of the nucleus
Cytoplasm
Jelly-like substance found inside cell that acts as a medium for
chemical reactions within the cell
Golgi Body (Apparatus)
Packages the proteins made by the ribosomes so they can be
sent out of the cell. The UPS store of the cell
Mitochondrion
"powerhouse of the cell" breaks down sugar molecules to release
energy, site of cellular respiration, double membrane, selfreplicating, contains own DNA, cristae
Vacuole
"Storage tanks" Can hold food, water or waste for the cell
Ribosome
Makes proteins for the cell, can be found attached to the
endoplasmic reticulum or free in the cytoplasm
Transportation network for the cell, moves materials around in
the cell
Endoplasmic Reticulum (ER)
Rough Endoplasmic Reticulum (RER)- endoplasmic reticulum that
has ribosomes attached.
Smooth Endoplasmic Reticulum (SER)- does not have ribosomes
attached
Lysosome
"Stomach of the cell" Helps the cell digest food, waste and worn
out cell parts
Nucleolus
Produces ribosomes and rRNA( stuff ribosomes are made of)
Cell Membrane (plasma membrane)
"Gatekeeper" Separates the cell from the rest of the
environment and helps control what passes in and out of the cell.
Semi-permeable: allows some materials to pass through but not
all
Chloroplast
A special plastid that contains chlorophyll a pigment that
captures the sun's energy to produce glucose in a process called
photosynthesis
Cell Wall
Rigid outer layer made of cellulose that supports and protects
the cell (plant, fungi, and bacterial cells)
Vesicle
Stores and Transports substances from the Golgi Body to the
cell membrane for export. "The UPS truck of the cell"
Cytoskeleton
gives support and shape to the cell, made of proteins
Centriole
Organizes special parts of the cytoskeleton called microtubules
for cell division, migrates to opposite ends (poles) of the cell to
assist with cell division
The Mitosis Cell Cycle
Before a cell starts dividing, it is in the "Interphase." It seems that cells must be constantly dividing (remember there are 2 trillion cell
divisions in your body every day), but each cell actually spends most of its time in the interphase. Interphase is the period when a
cell is getting ready to divide and start the cell cycle. During this time, cells are gathering nutrients and energy. The parent cell is
also making a copy of its DNA to share equally between the two daughter cells.
The mitosis division process has several steps or phases of the cell cycleinterphase, prophase, prometaphase, metaphase,
anaphase, telophase, and cytokinesisto successfully make the new diploid cells.
The mitosis cell cycle includes several phases that result in two new diploid daughter cells. Each phase is
highlighted here and shown by light microscopy with fluorescence. Click on the image to learn more
about each phase. (Image from OpenStax College with modified work by Mariana Ruiz Villareal, Roy
van Heesheen, and the Wadsworth Center.)
When a cell divides during mitosis, some organelles are divided between the two daughter cells. For example, mitochondria are
capable of growing and dividing during the interphase, so the daughter cells each have enough mitochondria. The Golgi apparatus,
however, breaks down before mitosis and reassembles in each of the new daughter cells. Many of the specifics about what happens
to organelles before, during and after cell division are currently being researched. (You can read more about cell parts and
organelles by clicking here.)
Meiosis Cell Division
Meiosis is the other main way cells divide. Meiosis is cell division that creates sex cells, like female egg cells or male sperm cells.
What is important to remember about meiosis? In meiosis, each new cell contains a unique set of genetic information. After
meiosis, the sperm and egg cells can join to create a new organism.
Meiosis is why we have genetic diversity in all sexually reproducing organisms. During meiosis, a small portion of each chromosome
breaks off and reattaches to another chromosome. This process is called "crossing over" or "genetic recombination." Genetic
recombination is the reason full siblings made from egg and sperm cells from the same two parents can look very different from one
another.
The meiosis cell cycle has two main stages of division -- Meiosis I and Meiosis II. The end result of
meiosis is four haploid daughter cells that each contain different genetic information from each other and
the parent cell. Click for more detail. (Image from Science Primer from the National Center for
Biotechnology Information.)
The Meiosis Cell Cycle
Meiosis has two cycles of cell division, conveniently called Meiosis I and Meiosis II. Meiosis I halves the number of chromosomes
and is also when crossing over happens. Meiosis II halves the amount of genetic information in each chromosome of each cell. The
end result is four daughter cells called haploid cells. Haploid cells only have one set of chromosomes - half the number of
chromosomes as the parent cell.
Before meiosis I starts, the cell goes through interphase. Just like in mitosis, the parent cell uses this time to prepare for cell division
by gathering nutrients and energy and making a copy of its DNA. During the next stages of meiosis, this DNA will be switched
around during genetic recombination and then divided between four haploid cells.
So remember, Mitosis is what helps us grow and Meiosis is why we are all unique!
