Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
You can change this under Settings & Account at any time.
Cells: The Building Blocks of Life
Transcript of Cells: The Building Blocks of Life
the size of the dot on an "i." A human red blood
cell is even smaller! A bacterium is even
smaller than that - 8,000 of the
smallest bacteria can fit
inside one red
blood cell! Cells are different shapes. Nerve cells have
long fibers that come out of them.
Some cells, such as muscle
and some blood cells,
can even change
shape! Something Else to Think About Something to Think About... Two Types of Cells Prokaryotic Eukaryotic Cells without membrane-bound structures are called prokaryotic. These are only found in one-celled organisms, such as bacteria. Cells with membrane-bound structures are called eukaryotic. Protists, fungi, plants, and animals are made of eukaryotic cells. Vocabulary protective outer covering of all cells that is made up of a double layer of fatlike molecules and regulates the interaction between the cell and the environment rigid structure that encloses, supports, and protects the cells of plants Cell membrane - Cell wall - Vocabulary cytoplasm - gelatinlike substance inside cells that constantly flows inside the cell membrane; many important chemical reactions occur within it cytoskeleton - a framework that is throughout the cytoplasm and is made up of thin, hollow tubes of protein and thin, solid protein fibers; helps a cell maintain or change its shape Cytoplasm Manufacturing Organelles Processing, Transporting, and Storing Organelles Most of a cell's life processes occur in the cytoplasm. The cytoplasm of all cells is full of organelles, which are structures that have many different functions. Recycling Organelles Cells require
a continuous supply
of energy to process food, make new substances, eliminate wastes, and communicate with
each other. In plant cells, food is made in green organelles called chloroplasts. These contain the green pigment, chlorophyll, which is why leaves are green.
Chlorophyll captures light and makes glucose, which is what the plant needs for energy. Glucose molecules store the captured light as chemical energy. Energy-Processing Organelles Many animal cells don't have chlorplasts for making food - they have to get their food from the environment. Mitochondria Chloroplasts Mitochondria are organelles where energy is released from breaking down food into carbon dioxide and water. Active cells, such as muscle cells, have more mitochondria, because they need more energy. Endoplasmic
Reticulum The endoplasmic reticulum, or ER, extends from the nucleus to the cell membrane. It is a series of folded membranes in which materials can be processed and moved around inside the cell. The ER takes up a lot of space in some cells. The endoplasmic reticulum could be rough or smooth.
If the endoplasmic reticulum has no attached ribosomes, it is called smooth endoplasmic reticulum. This type of ER processes other cellular substances such as lipids that store energy.
Ribosomes are attached to areas on the rough ER. There, they carry out their job of making proteins that are moved out of the cell or used within the cell. Ribosomes Even though
ribosomes are considered
organelles, they are not membrane
bound. Some ribosomes float freely in the cytoplasm, and others are attached to the endoplasmic reticulum. Ribosomes are made in the nucleus and move out into the cytoplasm. Ribosomes receive directions from the hereditary material in the nucleus on how, when, and in what order to make specific proteins. Protein takes part in almost every cell activity. Proteins are part of cell membranes. Some proteins are needed for chemical reactions that take place in the cytoplasm. Cells make their own proteins on small structures
called ribosomes. Golgi Bodies After proteins are made in a cell,
they are transferred to the Golgi Bodies,
which are stacked, flattened membranes that
sort proteins and other cellular substances and package them into mebrane-bound
structures called vesicles. Lysosomes The vesicles deliver
cellular substances to areas
inside the cell. They also carry cellular
substances to the cell membrane, where they
are released to the outside of
the cell. Vesicles Vacuoles Active cells need to break down and recycle many substances. Organelles called lysosomes contain digestive chemicals that help break down food molecules, cell wastes, and worn-out cell parts. Cells have membrane-bound spaces called vacuoles, that are used for the temporary storage of materials. A vacuole can store water, waste products, food, and other cellular materials. In plant cells, the vacuole may make up most of the cell's volume. In a healthy cell,
chemicals are released into
vacuoles only when needed. The
lysosome's membrane prevents the
digestive chemicals inside from leaking
into the cytoplasm and destroying
the cell. When the cell dies,
a lysosomes membrane
disintegrates. Nucleus The nucleus directs all cell activities and is separated from the cytoplasm by a membrane. It contains the instructions for everything that the cell does. These instructions are found in long, threadlike, hereditary material made of DNA. DNA is the chemical that contains the code for the cell's structures and activities. During cell division, the hereditary material coils tightly around proteins to form structures called chromosomes. A structure called a nucleolus is found in the nucleus.