Download video slide

CHAPTER 4
A Tour of the Cell- Flashcard
info alternative
PowerPoint® Lectures for
Essential Biology, Third Edition
– Neil Campbell, Jane Reece, and Eric Simon
Essential Biology with Physiology, Second Edition
– Neil Campbell, Jane Reece, and Eric Simon
Lectures by Chris C. Romero
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Eukaryotic cells are partitioned into functional
compartments
All other life forms are made up of one or more
eukaryotic cells
These are larger and more complex than
prokaryotic cells
Eukaryotes are distinguished by the presence of
a true nucleus
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
A Panoramic View of Eukaryotic Cells
• An idealized animal cell
Cytoplasmic Streaming
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 4.6b
The Plasma Membrane
Would this organelle/ structure also be found in prokaryotes?
If so, are there any important differences in structure or function?
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The Plasma Membrane:
A Fluid Mosaic of Lipids and Proteins
• The plasma membrane separates the living cell
from its nonliving surroundings.
• The membranes of cells are composed mostly of:
– Lipids
– Proteins
Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings
The plasma membrane
• The lipids belong to a special category called
phospholipids.
• Phospholipids form a two-layered membrane, the
phospholipid bilayer.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The plasma membrane
• Most membranes have
specific proteins
embedded in the
phospholipid bilayer.
• Membranes also contain
cholesterol wedged
between the
phospholipids.
• Carbohydrates are found
on the external surface
attached to phospholipids
or protein.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
• Membrane phospholipids and proteins can drift
about in the plane of the membrane.
• This behavior leads to the description of a
membrane as a fluid mosaic:
– Molecules can move freely within the membrane.
– A diversity of proteins exists within the
membrane.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Cell Surfaces
• Most cells secrete materials for coats of one kind or
another
– That are external to the plasma membrane.
• These extracellular coats help protect and support
cells
– And facilitate interactions between cellular
neighbors in tissues.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
• Animal cells have an
extracellular matrix,
– Which helps hold cells
together in tissues and
protects and supports
them.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The Cell Wall
Would this organelle/
structure also be found
in prokaryotes?
If so, are there any
important differences
in structure or
function?
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
• Plant cells have cell walls,
– Which help protect the cells, maintain their shape,
and keep the cells from absorbing too much water.
– Made of Cellulose and other components in plant
cells
– Prokaryotes’ cell wall performs the same function,
though it is composed of different organic molecules
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
• Cell Junctions
– “Tunnels” that
Connects the cytoplasm
of one plant cell with
the cytoplasm of
another plant cell, thus
allowing small
substances to move
from cell to cell.
– There are other types of
junctions, but that is for
Advanced bio I
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Ex: cell Junctions
The Nucleus
Would this organelle/
structure also be found in
prokaryotes?
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The Nucleolus
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 4.8
The Nucleus and Ribosomes:
Genetic Control of the Cell
• The nucleus is the manager of the cell
– Genes in the nucleus store information necessary
to produce proteins which direct the cell’s
activities
• It is usually the largest organelle.
• It contains chromatin (DNA)
• The nucleus is separated from the cytoplasm by the
nuclear envelope.
Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings
Structure and Function of the Nucleolus
• The nucleolus is found within the nucleus
– It is a mass of fibers and granules
– It is where ribosomes are made
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Ribosomes
Would this organelle/ structure also be found in prokaryotes?
If so, are there any important differences in structure or
function?
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Ribosomes
• Ribosomes are
responsible for protein
synthesis.
• DNA controls the cell by
transferring its coded
information into RNA.
– The information in
the RNA is used by
ribosomes to make
proteins.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The Endomembrane System: Manufacturing and
Distributing Cellular Products
The endomembrane system is a collection of
membranous organelles
• These organelles manufacture and distribute cell
products
• The endomembrane system divides the cell into
compartments
Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings
Figure 4.10
The Endoplasmic Reticulum
• The endoplasmic reticulum (ER)
– Produces an enormous variety of molecules.
– Is composed of smooth and rough ER.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Rough Endoplasmic Reticulum
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Rough ER makes membrane and proteins
• The “roughness” of the rough ER is due to
ribosomes that stud the outside of the ER
membrane.
• The functions of the rough ER include:
– Producing two types of membrane proteins
– Producing new membrane
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Rough Endoplasmic REticulum
• After the rough ER synthesizes a molecule, it
packages the molecule into transport vesicles.
Transport vesicle
buds off
4
Ribosome
Sugar
chain
1
3
Secretory
(glyco-) protein
inside transport
vesicle
Glycoprotein
2
Polypeptide
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
ROUGH ER
Smooth Endoplasmic Reticulum
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Smooth ER
• Continuous with the rough ER
• Lacks the surface ribosomes of ER
• Produces lipids, including steroids.
–
For example how cells in your ovaries or testes produce steroid based
sex hormones like estrogen and testosterone
• In some cells, it regulates carbohydrate metabolism
•
In liver cells breaks down toxins and drugs
–
Antibiotics, barbiturates, alcohol
• In other cells- especially muscle cells it stores calcium
ions.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The Golgi Complex
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 4.12
The Golgi Apparatus
• The Golgi apparatus
– Works in partnership with the ER.
– It consists of stacks of membranous sacs
– Refines, stores, and distributes the chemical
products of cells.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Vesicles
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Lysosomes
• A lysosome is a
membrane-enclosed sac.
– It contains digestive
enzymes.
– The enzymes break
down
macromolecules.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 4.13a
Figure 4.13b
• Lysosomes have several types of digestive
functions.
– They fuse with food vacuoles to digest the
food.
– They break down damaged organelles.
Lysosome Formation
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Connection: Abnormal lysosomes can cause fatal
diseases
Lysosomal storage diseases are hereditary
• They interfere with other cellular functions
• Examples: Pompe’s disease, Tay-Sachs disease
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Vacuoles
• Vacuoles are membranous sacs.
– Two types are the contractile vacuoles of protists and the
central vacuoles of plants.
Paramecium Vacuole
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The Central Vacuole
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Vacuoles function in the general maintenance of the
cell
Plant cells contain
a large central
vacuole
• The vacuole
absorbs water,
stores vital
chemicals,
stores waste
products
Central
vacuole
Nucleus
Figure 4.13A
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Protists may have contractile vacuoles
• These pump out excess water
Nucleus
Contractile
vacuoles
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 4.13B
Figure 4.15
Chloroplasts and Mitochondria:
Energy Conversion
• Cells require a constant energy supply to do all the
work of life.
• This function is carried out by the chloroplasts and
the mitochondria
Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings
Chloroplasts
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Chloroplasts
• Chloroplasts are found in
plants and some protists.
• Chloroplasts are the sites
of photosynthesis, the
conversion of light energy
to chemical energy in
sugars.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Mitochondria
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Mitochondria
• Mitochondria are the sites
of cellular respiration,
which involves the
production of ATP from
food molecules.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
• Mitochondria and chloroplasts share another
feature unique among eukaryotic organelles.
– They contain their own DNA.
• The existence of separate “mini-genomes” is
believed to be evidence that
– Mitochondria and chloroplasts evolved from
free-living prokaryotes in the distant past.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Cytoskeleton
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The Cytoskeleton:
Cell Shape and Movement
• The cytoskeleton is an
infrastructure of the cell
consisting of a network of
fibers.
• One function of the
cytoskeleton is to provide
mechanical support to the
cell and maintain its
shape.
Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings
The Cytoskeleton
• The cytoskeleton can
change the shape of a cell.
• This allows cells like
amoebae to move.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Flagella
Would this organelle/
structure also be found
in prokaryotes?
If so, are there any
important differences in
structure or function?
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Cilia and Flagella
• Cilia and flagella are
motile appendages.
• Flagella propel the cell in
a whiplike motion.
• Cilia move in a
coordinated back-andforth motion.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Cilia and Flagella
• Some cilia or flagella
extend from nonmoving
cells.
• The human windpipe is
lined with cilia.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings