Transcript Fig. 7.18 CHAPTER 7 A TOUR OF THE CELL

CHAPTER 7 A TOUR OF THE CELL
Section B: A Panoramic View of the Cell
1. Prokaryotic and eukaryotic cells differ in size and complexity
2. Internal membranes compartmentalize the functions of a eukaryotic cell
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1. Prokaryotic and eukaryotic cells differ in size and complexity
• All cells are surrounded by a ______________.
• The semifluid substance within the membrane is the
__________, containing the ____________.
• All cells contain chromosomes which have genes in
the form of DNA.
• All cells also have ___________, tiny organelles that
make _________ using the instructions contained in
_______.
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• Cells are divided into two main types: ________
cells and _________ cells
• A major difference is the ________ of
chromosomes.
• In a eukaryotic cell, chromosomes are contained in
a membrane bound organelle, the _________.
• In a prokaryotic cell, the DNA is concentrated in
the ____________ without a membrane separating
it from the rest of the cell.
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Fig. 7.4 The prokaryotic cell is much simpler in structure, lacking a nucleus and the other membraneenclosed organelles of the eukaryotic cell.
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• In eukaryote cells, the region between the nucleus
and the plasma membrane is the ___________.
• All the material within the plasma membrane of a
prokaryotic cell is cytoplasm.
• Within the cytoplasm of a eukaryotic cell is a
variety of membrane-bounded organelles of
__________________.
• These membrane-bounded organelles are _______ in
prokaryotes.
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• Eukaryotic cells are generally much ________ than
prokaryotic cells.
• The logistics of carrying out metabolism set
________ on cell size.
• At the lower limit, the smallest bacteria, mycoplasmas,
are between 0.1 to 1.0 micron.
• Most bacteria are 1-10 microns in diameter.
• Eukaryotic cells are typically 10-100 microns in
diameter.
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• The plasma membrane functions as a ___________
____________ that allows passage of oxygen,
nutrients, and wastes for the whole volume of the cell.
Fig. 7.6
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• The volume of cytoplasm determines the need for
this exchange.
• Rates of chemical exchange may be _________ to
maintain a cell with a very ______ cytoplasm.
• The need for a surface sufficiently large to
accommodate the volume explains the microscopic
size of most cells.
• Larger organisms do not generally have larger cells
than smaller organisms - simply _____ cells.
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2. Internal membranes compartmentalize the functions of a eukaryotic
cell
• A eukaryotic cell has extensive and elaborate ________
_____________, which partition the cell into compartments.
• The barriers created by membranes provide different ________
______________ that facilitate specific metabolic functions.
• The general structure of a biological membrane is a ____________
of __________ with other lipids and diverse proteins.
• Each type of membrane has a unique combination of lipids and
proteins for its specific functions.
• For example, those in the membranes of mitochondria function
in cellular respiration.
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Fig. 7.7
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Fig. 7.8
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CHAPTER 7 A TOUR OF THE CELL
Section C: The Nucleus and Ribosomes
1. The nucleus contains a eukaryotic cell’s genetic library
2. Ribosomes build a cell’s proteins
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1. The nucleus contains a eukaryotic cell’s genetic library
• The ________ contains most of the _______ in a
eukaryotic cell.
• Some genes are located in _________ and ____________.
• In the nucleus is a region of densely stained fibers
and granules adjoining chromatin, the _________.
• In the nucleolus, ribosomal RNA (_______) is synthesized
and assembled with proteins from the cytoplasm to form
ribosomal subunits.
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Fig. 7.9
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2. Ribosomes build a cell’s proteins
• ___________ contain rRNA and protein.
• A ribosome is composed of two subunits that
combine to carry out _______________
Fig. 7.10
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• Some ribosomes, ________ ribosomes, are
suspended in the cytosol and synthesize proteins
that function within the cytosol.
• Other ribosomes, _________ ribosomes, are
attached to the outside of the ___________
____________.
• These synthesize proteins that are either included into
membranes or for export from the cell.
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CHAPTER 7 A TOUR OF THE CELL
Section D: The Endomembrane System
1. The endoplasmic reticulum manufactures membranes and performs many
other biosynthetic functions
2. The Golgi apparatus finishes, sorts, and ships cell products
3. Lysosomes are digestive compartments
4. Vacuoles have diverse functions in cell maintenance
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Introduction
• Many of the internal membranes in a eukaryotic cell
are part of the ______________________.
• These membranes are either in direct contact with
one another or are connected via transfer of _______,
sacs of membrane.
• The endomembrane system includes the __________
_______, endoplasmic reticulum, _____________,
lysosomes, _________, and the plasma membrane.
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1. The endoplasmic reticulum manufactures
membranes and performs many other
biosynthetic functions
• The endoplasmic reticulum (_____) accounts for
_____ the membranes in a eukaryotic cell.
• There are two, albeit connected, regions of ER that
differ in structure and function.
• ___________ looks smooth because it ______________.
• ___________ looks rough because ribosomes (bound
ribosomes) are attached to the outside, including the
outside of the nuclear envelope.
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• Enzymes of smooth ER
synthesize ______,
including oils,
phospholipids, and steroids.
• The smooth ER also
catalyzes a key step in the
mobilization of _________
_____________________.
• Other enzymes in the
smooth ER help ______
drugs and poisons.
Fig. 7.11
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• Rough ER is especially abundant in those cells that
secrete proteins.
• These secretory proteins are packaged in ________
________ that carry them to their next stage.
• Rough ER is also a ________ factory.
• Membrane bound proteins are synthesized directly into
the membrane.
• Enzymes in the rough ER also synthesize membrane
phospholipids from precursors in the cytosol.
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2. The Golgi apparatus finishes, sorts, and
ships cell products
• Many transport vesicles from the ER travel to the
_____________ for modification of their contents.
• The Golgi is a center of manufacturing, warehousing,
_______, and ____________.
• The Golgi apparatus is especially extensive in cells
specialized for secretion.
• The Golgi apparatus consists of flattened membranous
sacs - _________ - looking like a stack of pita bread
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Fig. 7.12
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3. Lysosomes are digestive compartments
• The ________ is a membrane-bounded sac of
_________ enzymes that ________ macromolecules.
Fig. 7.13a
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• Lysosomal enzymes can hydrolyze proteins, fats,
polysaccharides, and nucleic acids.
• These enzymes work best at _______.
• While rupturing one or a few lysosomes has little
impact on a cell, massive leakage from lysosomes
can destroy an cell by _________________.
• The lysosomes create a space where the cell can
digest macromolecules _______.
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• Lysosomes can fuse with food vacuoles, formed
when a food item is brought into the cell by
________________.
• As the polymers are digested, their monomers pass out
to the cytosol to become nutrients of the cell.
• Lysosomes can also
fuse with another
organelle or part
of the cytosol.
• This recycling,
or
__________,
renews the cell.
Fig. 7.13b
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4. Vacuoles have diverse functions in cell maintenance
• Vesicles and vacuoles (larger versions) are
membrane-bound sacs with varied functions.
• ____________, from phagocytosis, fuse with lysosomes.
• _______________, found in freshwater protists, pump
excess water out of the cell.
• _______________ are found in many mature plant cells.
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Fig. 7.15
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CHAPTER 7 A TOUR OF THE CELL
Section E: Other Membranous Organelles
1. Mitochondria and chloroplasts are the main energy transformers of cells
2. Peroxisomes generate and degrade H2O2 in performing various metabolic
functions
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1. Mitochondria and chloroplasts are the
main energy transformers of cells
• Mitochondria and chloroplasts are the organelles that
convert energy to forms that cells can use for work.
• _____________ are the sites of _________________,
generating ______ from the catabolism of sugars,
fats, and other fuels in the presence of oxygen.
• ___________, found in plants and eukaryotic algae,
are the sites of ____________.
• They convert solar energy to chemical energy and
synthesize new organic compounds from CO2 and H2O.
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• Mitochondria and chloroplasts are not part of the
endomembrane system.
• Both organelles have small quantities of _______,
separate from the nucleus
• Mitochondria and chloroplasts grow and reproduce
as ________________ organelles.
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• Almost all eukaryotic cells have mitochondria.
• There may be one very large mitochondrion or hundreds to
thousands of individual mitochondria.
• The number of mitochondria is __________ with aerobic
metabolic activity.
• Mitochondria have a smooth outer membrane and a highly folded
inner membrane, the ________.
• The inner membrane encloses the ______________________, a
fluid-filled space with DNA, ribosomes, and enzymes.
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Fig. 7.17
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• The chloroplast produces sugar via photosynthesis.
• Chloroplasts gain their color from high levels of the green
pigment ___________.
• Chloroplasts are found in leaves and other green
structures of plants and in eukaryotic algae.
• The processes in the chloroplast are separated from
the cytosol by ______________.
• Inside the innermost membrane is a fluid-filled
space, the _______, in which float membranous
sacs, the ____________.
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Fig. 7.18
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CHAPTER 7 A TOUR OF THE CELL
Section G: Cell Walls
1. Plant cells are encased by cell walls
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1. Plant cells are encased by cell walls
• The __________, found in prokaryotes, fungi, and some protists,
has multiple functions.
• In plants, the cell wall protects the cell, maintains its shape, and
prevents excessive uptake of water.
• It also supports the plant against the force of gravity.
• The thickness and chemical composition of cell walls differs from
species to species and among cell types.
• Plants- _______
• Fungi-________
• Bacteria- lipopolysachharide and _________________
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