Transcript Chapter 7 Section 2

Chapter 7 Section 2
Figure 7-5 Plant and Animal Cells
Section 7-2
Nucleolus
Nucleus
Ribosome
(attached)
Nuclear
envelope
Ribosome
(free)
Cell
Membrane
Mitochondrion
Smooth
endoplasmic
reticulum
Rough
endoplasmic
reticulum
Centrioles
Golgi apparatus
Animal Cell
Figure 7-5 Plant and Animal Cells
Section 7-2
Smooth endoplasmic
reticulum
Vacuole
Ribosome
(free)
Chloroplast
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Cell wall
Nucleolus
Golgi apparatus
Nucleus
Mitochondrion
Rough endoplasmic reticulum
Plant Cell
Venn Diagrams
Section 7-2
Prokaryotes
Eukaryotes
Cell membrane
Contain DNA
Animal Cells
Centrioles
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Eukaryote Cell Structure
• Many of the structures inside a cell act like
organs, so they are called ORGANELLES, which
literally means “little organs”.
• Cell biologists divide a cell into two parts:
• 1. the nucleus, and
• 2. the cytoplasm.
• The cytoplasm is the portion of the cell
outside the nucleus.
The Nucleus
• The nucleus is the control center of the cell.
• It contains nearly all of the cell’s DNA and with
it the coded instructions for making proteins
and other molecules.
• It controls most of the cell processes.
• The nucleus is surrounded by a nuclear
envelope which is composed of two
membranes.
• The nuclear envelope is dotted with
thousands of pores, which allow material to
move into and out of the nucleus.
• Chromatin appears as a granular substance
inside the nucleus.
• Chromatin consists of DNA bound protein.
• When the cell divides, the chromatin
condenses into strands that form
chromosomes.
• Chromosomes contain the genetic information
that is passed on to the next generation of
offspring.
• Most nuclei contain a small, dense region
called the nucleolus. This is where the
assembly of ribosomes begins.
• Ribosomes are where proteins are assembled.
• Ribosomes are small particles of RNA and
protein found in the cytoplasm.
• Each ribosome is like a small factory, making
proteins on orders that come from its “boss”,
the cell nucleus.
• Eukaryotic cells contain an internal membrane
system called the endoplasmic reticulum, or ER.
• The ER is the site where lipid components of the
cell membrane are assembled, along with
proteins and other materials that are exported
from the cell.
• Rough ER is involved in the making of proteins. It
is called rough ER because of the ribosomes
found on its surface.
• ER without ribosomes attached to it is known
as smooth ER.
• Smooth ER performs many tasks, such as
detoxifying drugs. Liver cells, which break
down and destroy many drugs that enter the
body, contain large amounts of smooth ER.
• Proteins produced in the rough ER move into
the organelle called the Golgi apparatus.
• The function of the Golgi apparatus is to
modify, sort and package proteins and other
materials from the ER for storage in the cell or
to secrete them outside the cell.
• The finishing touches are put on proteins and
then they are sent on their way either inside
the cell or outside the cell.
• Lysosomes are small organelles filled with
enzymes.
• One function of a lysosome is the breakdown
of lipids, carbohydrates, and proteins into
smaller parts that can be recycled. It is the
cleanup crew for the cell.
• Vacuoles are saclike structures that store
materials such as water, salts, proteins, and
carbohydrates.
• In many plant cells there is a single, large
central vacuole filled with liquid. This liquid
causes pressure on the cell that allows it to be
rigid, which allows it to support stems, leaves,
and flowers.
• Nearly all eukaryotic cell contain
mitochondria (single mitochondrion).
• Mitochondria are organelles that convert the
chemical energy stored in food into
compounds that are more convenient for the
cell to use.
• Mitochondria are called the powerhouses of
the cell.
• Chloroplasts are organelles that capture the
energy from sunlight and convert it into
chemical energy in a process called
photosynthesis.
• They contain the green pigment chlorophyll.
Endosymbiotic Theory
• The idea that chloroplasts and mitochondria
are descendants of prokaryotes.
• They then created a symbiotic relationship
with eukaryotes and moved into their cells to
take up residence.
Cytoskeleton
• The cytoskeleton is a network of protein
filaments that helps the cell to maintain its
shape. The cytoskeleton is also involved in
movement of cells.
• Microfilaments called actin form networks
and a tough frame that supports the cell.
• Microtubules called tubulins help maintain
shape as well. They also play a role during cell
division by helping separate chromosomes.
• Centrioles are tubulins found in animal cells
that help organize cell division.
Figure 7-11 Cytoskeleton
Section 7-2
Cell membrane
Endoplasmic
reticulum
Microtubule
Microfilament
Ribosomes
Mitochondrion