Chapter 3 – Part 1
Cell Organelles
The Cell Theory
1.
2.
3.
All living things are composed of cells.
Cells are the basic units of structure and
function in living things.
New cells are produced from existing
cells.
Organelles

Organelles - “Little organs” in a cell
Cytoplasm

Cytoplasm - The portion of the cell outside
the nucleus (jelly like material)
Nucleus

Nucleus - Contains nearly all the cell's
DNA (genetic information)

Sends orders to the organelles (the boss).
Nuclear Envelope

Nuclear Envelope - Layer
of two membranes that
surrounds the nucleus of a
cell

Dotted with thousands of
nuclear pores, which allow
material to move into and
out of the nucleus (such as
DNA or proteins)
Nucleolus

Nucleolus - Small, dense region within
most nuclei in which the assembly of
proteins begins
Chromatin & Chromosomes


Chromatin - granular material visible
within the nucleus; consists of DNA tightly
coiled around proteins
Chromosome - Threadlike structure within
the nucleus containing the genetic
information that is passed from one
generation of cells to the next

When a cell divides chromatin condenses to
form chromosomes
Ribosomes

Ribosomes – Where proteins are
assembled


Are small particles of RNA and protein found
throughout the cytoplasm
Like a small machine in a factory that
produces proteins
Endoplasmic Reticulum

Endoplasmic Reticulum (ER) - Internal
membrane system in cells in which lipid
components of the cell membrane are
assembled and some proteins are
modified
Rough Endoplasmic Reticulum

Rough ER- The portion
of the ER involved in
the synthesis of
proteins


Given this name
because of the
ribosomes found on its
surface.
Abundant in cells that
produce large amounts
of protein for export.
Smooth Endoplasmic Reticulum

Smooth ER –
Endoplasmic reticulum
where ribosomes are not
found on its surface

Contains collections of
enzymes that perform
specialized tasks
including:
1.
2.
synthesis of membrane
lipids
detoxification of drugs
Golgi Apparatus

Golgi Apparatus - Modify, sort, and
package proteins and other materials from
the endoplasmic reticulum for storage in
the cell or secretion outside the cell.

Finishing touches are put on proteins before
they are ready to leave the “factory.”
Lysosomes


Lysosomes - Cell organelle filled with
enzymes needed to break down certain
materials in the cell
Functions:


Digestion of lipids, carbohydrates, and
proteins into small molecules that can be used
by the cell
Breaking down organelles that have outlived
their usefulness
Vacuoles

Vacuoles – Sac like structure that stores
materials such as water, salts, proteins,
and carbohydrates.

Plants contain large vacuoles
Mitochondria

Mitochondria - Organelles that convert the
chemical energy stored in food into
compounds that are more convenient for
the cell to use.
Chloroplasts

Chloroplasts - Organelles
that capture the energy
from sunlight and
convert it into chemical
energy in a process
called photosynthesis.


Like a solar power plant.
Contain the green
pigment chlorophyll.
Centrioles

Centrioles – Direct the formation of the
mitotic spindle in cell division



Rod-shaped bodies that lie at right angles to
each other
Lie close to the nucleus
Paired
Cytoskeleton

Cytoskeleton Network of protein
filaments within
some cells that helps
the cell maintain its
shape and is
involved in many
forms of cell
movement
Cytoskeleton Continued

Examples of Cytoskeleton

1. Microfilaments - Threadlike structures
made of a protein called actin

Used for support and movement
Cytoskeleton Continued

Examples of Cytoskeleton

2. Microtubules - Hollow structures made
up of proteins known as tubulins; help
maintain shape and used to separate
chromosomes in cell division


Centrioles - Structure located in the cytoplasm of
animal cells near the nucleus and help to organize cell
division.
Also help to build projections from the cell surface,
which are known as cilia and flagella

Enable cells to swim rapidly through liquids
Cell Membrane

Cell Membrane - Thin, flexible barrier
around a cell; regulates what enters and
leaves the cell
Cell Wall

Cell Wall - Strong
supporting layer around
the cell membrane in
plants, algae, and some
bacteria

Most are made from
fibers of carbohydrate
(cellulose) and protein
Cell Specialization

Cell Specialization - Separate roles for
each type of cell in multi-cellular
organisms

Cells throughout an organism can develop in
different ways to perform different tasks.
What is the organelle labeled #9?
What is the organelle labeled #5?
What is the organelle labeled #6?
What is the
organelle
labeled #14?
What is the
organelle
labeled # 2?