Download cell organelles and features

CELL ORGANELLES AND FEATURES
Eukaryotic cells have many membrane systems. These membranes divide cells into
compartments that function together to keep cells alive.
OBJECTIVES:
1. Describe the structure and function of a cell's plasma membrane.
2. Summarize the role of the nucleus.
3. List the major organelles found in the cytosol and Describe their roles.
4. Identify characteristics of mitochondria.
5. Describe the structure and function of the cytoskeleton.
THE PLASMA OR CELL MEMBRANE

The Plasma Membrane is a complex barrier separating the cell from it's external
environment controlling what enters and leaves the cell.

The Cell Membrane CONTROLS the ease with which substances pass into and
out of the cell-some substances easily cross the membrane, while others cannot
cross at all. For this reason

This "___________ - ____________" Membrane regulates what passes into and
out of the cell.

The Cell Membrane consists of ___ thin layers of ______________________that
separate the cell's content from the world around it.

The TWO Phospholipid LAYERS are together are called a __________________
_____________________.

The Cell Membrane is constantly being formed and broken down in living cells.
THE NUCLEUS (plural, Nuclei)

The Nucleus is _____________ often the most obvioustructure within a Eukaryotic
Cell.

The Nucleus is the ________________ _________________ (BRAIN) of the Cell.

Most Cells have a Single Nucleus some cells have more than one.

The nucleus is surrounded by a Double Layer Membrane called the
______________ - _____________________ covered with many small pores
through which PROTEINS and CHEMICAL MESSAGES from the Nucleus can
pass.

The Nucleus contains_______, the HEREDITARY MATERIAL OF CELLS.

The DNA is in the form of a long Strand called ______________________.

__________________

The ____________________MAKES (synthesizes) RIBOSOMES, WHICH IN
TURN, BUILD PROTEINS.

During Cell Division, Chromatin strands COIL and CONDENSES into thick
structures called _________________________.

The Chromosomes in the nucleus contain coded
"BLUEPRINTS" or _______________ that control all cellular activity.
CYTOPLASM

This includes the _______________, the ___________________, and all the
organelles Except the Nucleus.

_______________________ is a jellylike mixture that consists MOSTLY OF
WATER, along with PROTEINS, CARBOHYDRATES, SALTS, MINERALS and
ORGANIC MOLECULES.

Suspended in the Cytosol are tiny ___________________________ (ORGANS).
CYTOSKELETON

Just as your body depends on your skeleton to maintain its shape and size, so a
Cell needs structures to maintain its shape and size.

In Animal Cells, an internal framework called CYTOSKELETON maintains the
Shape of the Cell.

THE CYTOSKELETON MAINTAINS THE THREE-DIMENSIONAL STRUCTURE
OF THE CELL, PARTICIPATES IN THE MOVEMENT OF ORGANELLES
WITHIN THE CYTOSOL, AND HELPS THE CELL MOVE.
The CYTOSKELETON consists of : ________________ and _________________ .
MICROTUBULES (figure 4-18)
Microtubules are HALLOW TUBES like plumbing pipes.
They are the Largest Strands of the Cytoskeleton.
Microtubules are made of a PROTEIN called TUBULIN.
MICROFILAMENTS

MICROFILAMENTS are NOT HALLOW and have a structure that resembles
ROPE made of TWO TWISTED CHAINS OF PROTEIN called ACTIN.
Microtubules have THREE FUNCTIONS:

To maintain the shape of the cell and hold organelles in place.

To serve as tracks for organelles and molecules to move along within the cell.

When the Cell is about to divide, two short cylinders of Microtubules at right
angles known as Centrioles can be found situated in the cytoplasm near the
nuclear envelope.
Centrioles organize the micortubules of the cytoskeleton
during Cell Division in animal cells, plant cells lack
centrioles. (figure 7-11)

MITOCHONDRIA (MET-oh-KAHN-dree-uh) THE "___________________" OF THE
CELL.

Mitochondria are found scattered throughout the Cytosol, and are relatively Large
Organelles.

Mitochondria are the sites of Chemical Reactions that transfer
__________________from carbohydrates to ______ (an energy molecule used by
cells).

_____________ ___ ____________ is the molecule that most Cells use as their
main Energy Currency.

Mitochondria are Usually more numerous in Cells that have a High Energy
Requirement - Your muscle cells contain a large number of mitochondria.

Mitochondria is surrounded by TWO Membranes. (Figure 9-1 )
The inner membrane has many long folds,
known as ___________________ - which
greatly increases the surface area of the
inner membrane, providing more space for
the Chemical Reactions to occur.
Mitochondria have their own ___________, and new mitochondria arise only when
existing ones Grow and divide.

ATP Production is called ______________________ ___________________.
CHLOROPLAST

Found only in plant cells

__________________ is the process that converts H2O and CO2 into
carbohydrates using _________ energy.

Reactions take place in the _____________ and ____________ of the thylakoid
membrane system.
RIBOSOMES (RIE-buh-SOHMZ) (figure 7-8, 12-13)
Unlike most other organelles, Ribosomes are Not
surrounded by a membrane.
They are Most Numerous Organelles in almost all
cells.

Ribosomes are the site of __________________ ________________ in a cell.

Some are free in the Cytoplasm; others line the membranes of
______________________ ________________________ - a system of
membranous tubules and sacs.
ENDOPLASMIC RETICULUM

The ER functions Primarily as an Intracellular Highway, a path along which
molecules move from one part of the cell to another.

ER is an extensive network of membranes that connect the _____________ to the
_____________________ _____________________.

The amount of ER inside a cell fluctuates, depending on the Cell's Activity.

This organelle also helps to remove _____________ from the body.

Transports materials through the cell.

Can be ROUGH OR SMOOTH. (figure 7-8)
ROUGH ER is studded with __________________
and processes PROTEINS to be exported from the
cell.
SMOOTH ER IS NOT Covered with RIBOSOMES and
processes _______ and __________________. The
Smooth ER is involved in the synthesis of steroids in
gland cells, the regulation of calcium levels in muscle
cells, and the breakdown of toxic substances by liver
cells.
GOLGI APPARATUS (GOHL-jee) (Figure 7-9)
The Golgi Apparatus is the ________________,
_________________ and _______________ Organelle of the
Cell.
Made of Flattened SAC like Structures called
______________________.

It works Closely with the ER, the Golgi Apparatus modifies proteins for export by
the cell.

Golgi apparatus is also the site of producing vesicles called
___________________.
Known as “trash collectors of the cell”

Lysosomes are vesicles that bud (break off) from
the Golgi apparatus and that contain digestive
___________________________.
LYSOSOMES (LIE-suh-SOHMZ)

Lysosomes are small spherical organelles that enclose hydrolytic (digestive)
enzymes within a single membrane.
Lysosomes are the Site of Food Digestion in the Cell. They can break down large
molecules such as proteins, nucleic acids, carbohydrates, and phospholipids.

In the liver, they break down glycogen to release glucose into the blood stream.

Some white blood cells use lysosomes to break down bacteria.
CILIA AND FLAGELLA

Cilia and Flagella are Hair-like Organelles that extend from the surface of the
cell, where they assist in movement.

CILIA ARE SHORT HAIRLIKE PROJECTIONS.

FLAGELLA ARE LONG WHIPLIKE PROJECTIONS.

Unicellular organisms such as Paramecium and Euglena use Cilia and Flagella
to move through water.

Sperm use flagella to swim to the egg, beating Cilia line parts of the female
reproductive system to move egg to the uterus.
COMPARING CELLS (figure 7-20, 21)
1. Three unique features distinguish plant cells from animal cells:
(1) Plant cells have cell walls.
(2) Plant cells contain a large central vacuole.
3) Plant cells contain a variety of Plastids which are not found in animal cells.