Transcript Cell Organelles

7.2 Eukaryotic Cell Structure
 Comparing the Cell to a Factory
 Nucleus
 Ribosomes
 Endoplasmic Reticulum
 Golgi Apparatus
 Lysosomes
 Vacuoles
 Mitochondria and Chloroplasts
 Cytoskeleton
Comparing the Cell to a Factory
Organelles: structures in the cell that act
as specialized organs.
The cell is divided into two major parts:
the nucleus and the cytoplasm.
Cytoplasm: the portion of the cell outside
the nucleus.
Plant Cell
Animal Cell
Nucleus
 the control center of the cell
 Contains the cell’s DNA
 surrounded by the nuclear envelope
nuclear pores, which allow material to move into
and out of the nucleus.
 Chromatin: the granular material you can see in
the nucleus.
 Chromosomes: the condensed form of
chromatin that occurs during cell division.
 Nucleolus: a small, dense region; location of
assembly of ribosomes.
Structure of Nucleus
Like the central office of a factory.
Ribosomes
Site of protein synthesis.
Ribosomes: small particles of RNA and
protein found throughout the cytoplasm.
Look like dots throughout the cell.
Like a small machine in a factory, turning out
proteins on orders that come from its “boss” the
cell nucleus.
Endoplasmic Reticulum
 site where lipid components of the cell membrane are
assembled, along with proteins and other materials that
are exported from the cell.
 Rough ER: the portion involved in synthesis of proteins;
has ribosomes attached.
 Site of synthesis of proteins to be exported
 Smooth ER: no ribosomes are found on it
 Tasks include synthesis of membrane lipids and the
detoxification of drugs.
Structure of Endoplasmic Reticulum
Golgi Apparatus
 Appears as a stack of membranes.
 The function of the Golgi apparatus is to modify,
sort, and package proteins from the
endoplasmic reticulm
 Acts as a customization shop, where the
finishing touches are put on proteins before they
are ready to leave the “factory”
 From here, proteins are then “shipped” to their
final destinations throughout the cell or outside
of the cell.
Structure of Golgi Apparatus
Lysosomes
Small organelles filled with enzymes.
Function in digestion, or breakdown of
lipids, carbs, and proteins into small
molecules that can be used by the rest of
the cell.
Remove “junk” that otherwise accumulate
and clutter up the cell.
Acts as the “cleanup crew” of the factory.
Vacuoles
Saclike structures that store materials
such as water, salts, proteins, and carbs.
Acts as the “storage unit”.
In many plant cells there is a single, large
central vacuole filled with liquid.
Control water content and cell pressure.
Mitochondria and Chloroplasts
 Living things get energy in one of two ways: from food or from the
sun.
 Mitochondria:
 Found in nearly all eukaryotic cells.
 Organelles that convert the chemical energy stored in food into
compounds that are more convenient for the cell to use.
 Enclosed in two membranes
 They are inherited only from the mother!
 Act as powerhouse like in a factory.
 Chloroplasts:
 Found in plants and some single celled organisms
 Organelles that capture the energy from sunlight and convert it into
chemical energy in a process called photosynthesis
 Equivalent of solar power plants.
 Contain the pigment chlorophyll
 Both contain their own DNA
Structure of Mitochondria
Structure of Chloroplast
Cytoskeleton
Helps support the cell like the steel beams
or bricks that make up the building of a
factory.
Used to provide shape.
It is also involved in movement.
Centrioles are located near the nucleus
and help to organize cell division.
They are not found in plant cells.
Structure of Cytoskeleton