Download Ch 6 Powerpoint - Plain Local Schools

6.1 All organisms are made of
cells
I. The Cell Theory
A. In 1655 Robert Hooke observed
“compartments” in a thin slice of cork
which he named cells
B. In 1700 Anton van Leeuwenhoek had
developed light microscopes to
observe tiny living organisms which
he named “animalcules”
First microscopes
QuickTime™ and a
TIFF (Uncomp resse d) de com press or
are nee ded to s ee this picture.
Quic kTime™ and a
TIFF (Unc ompres sed) dec ompres sor
are needed to see this pic ture.
The Cell Theory
C. Cell theory is the generalization
that all living things are
composed of cells, and that cells
are the basic unit of structure and
function in living things
II. Microscopes as Windows to
Cells
A. Light microscopes can magnify
objects up to about 1,000 X
B. Electron microscopes can magnify
objects up to about 1,000,000 X
C. A photograph of the view taken
through a microscope is called a
micrograph
Microscopes
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Microscopes
SEM- scanning electron microscope
TEM- transmission
Both must use preserved specimens.
Microscopes
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
III. An Overview of Animal and
Plant Cells
A. Each part of a cell with a specific
job to do is called an organelle
B. The plasma membrane defines
the boundary of the cell and
regulates traffic in and out of the
cell
Overview of animal and plant
C. The nucleus stores the genetic
material of the cell
D. The region of the cell between
the nucleus and the plasma
membrane is called the
cytoplasm
Animal Cell
Animal Cell
Plant cell
Plant cell
IV. Two Major Classes of Cells
A. A prokaryotic cell lacks a
nucleus and most other
organelles
B. A eukaryotic cell has a
membrane bound nucleus and
organelles
Animal v. Plants
Animal
Plasma membrane
Plant
Membrane and cell
wall
Mitochondria
Mitochondria and
chloroplast
Cytoplasm, nucleus Both
Most organelles
Most organelles
Eukaryotic v. Prokaryotic
Eukaryotic
Nucleus
Plants and animals
Cytoplasm
Organelles
Prokaryotic
No nucleus
Bacteria
Cytoplasm
Lacks organelles
6.2 Membranes organize a cell’s
activities
I. Membrane Structure
A. Membranes regulate the transport
of substances across it
B. Membranes are composed mostly
of proteins and phospholipids
Membrane structure
C. The phospholipids form a twolayer sandwich called a
“phospholipid bilayer” which
surrounds the organelle or cell
D. The membranes are fluid-like
rather than sheets of molecules
locked rigidly into place
Plasma membrane
Plasma membrane
II. The Many Functions of
Membrane Proteins
A. Many types of proteins are embedded
in the membranes phospholipid
bilayer
B. Some proteins carry out some of the
cells important chemical reactions,
others helps cell communicate and
recognize each other, other proteins
move substances like sugar and water
across the membrane
Functions of Membrane Proteins
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
6.3 Membranes regulate the
traffic of molecules
I. Diffusion
A. Diffusion is the net movement of the
particles of a substance from where
they are more concentrated to where
they are less concentrated
B. Equilibrium is reached when the
movement of particles in one
direction is equal to the number of
particles moving in the other
Diffusion
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
II. Passive Transport
A. A selectively permeable
membrane allows some
substances to cross the membrane
more easily than others and
blocks the passage of some
substances altogether
Passive transport
B. Diffusion across a membrane is
called passive transport because no
energy is expended by the cell, only
the random motion of molecules is
required to move them across
C. Facilitated diffusion is when
transport proteins provide a pathway
for certain molecules to pass
Passive transport
Carbon dioxide, oxygen- nonpolar
Water, glucose - polar molecules
III. Osmosis
A. The passive transport of water across
a selectively permeable membrane is
called osmosis
B. A solution with a higher
concentration of solute is called
hypertonic hyper = “above”
C. A solution with a lower concentration
of solute is called hypotonic hypo =
“below”
III. Osmosis
D. A solution that has an equal
concentration of solute is called
isotonic iso = “equal”
- When an animal cell is placed in a
hypotonic solution it swells
- - When an animal cell is placed in a
hypertonic solution it shrinks
Osmosis
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
IV. Active Transport
A. When a cell expends energy to move
molecules or ions across a membrane
it is called active transport
B. A specific transport protein pumps a
solute across a membrane, usually in
the opposite direction it travels in
diffusion
Active Transport
Sodium / potassium pump
V. Transport of Large Molecules
A. Large molecules have to be
packed into vesicles, which are
small membrane sacs that
specialize in moving products
into, out of and within a cell
Transport of large molecules
B. When a cell exports its protein
products, a vesicle fuses with the
plasma membrane and spills its
contents outside the cell-a process
called exocytosis
C. The reverse process, endocytosis,
takes materials into the cell within
vesicles that bud inward from the
plasma membrane
Transport of large molecules
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
6.4 The cell builds a diversity of
products
I. Structure and Function of the
Nucleus
A. The nucleus in a cell contains DNA
which controls all of the activities
inside the cell
B. The nucleus is surrounded by the
nuclear envelope which has hole in
it which allow substances to pass in
and out of the nucleus
C. Inside the nucleus is the nucleolus
which contains parts necessary to
make ribosomes
nucleus
II. Ribosomes
A. DNA codes for the production of
proteins which are made in the
ribosomes
B. The ribosomes are either bound to
the surface of the endoplasmic
reticulum or suspended in the
cytoplasm
III. The Endoplasmic Reticulum
A. The endoplasmic reticulum is an
extensive network of membranes
which functions as the main
manufacturing and transportation
facility in the cell
1. Rough ER-The rough ER has ribosomes which insert
proteins right into or through the ER membrane or
packaged in vesicles and transported outside the cell
Endoplasmic Reticulum
2. Smooth ER-The smooth ER
lacks ribosomes but enzymes in
the smooth ER allow it to make
lipid molecules
IV. The Golgi Apparatus
A. The golgi apparatus receives
products from the ER and modifies,
stores and routes proteins and other
products to their final destination
B. This organelle is analogous to a
processing a shipping center of the
cell
V. Vacuoles
A. The cytoplasm has large, membrane
bound sacs called vacuoles
B. Some vacuoles contain undigested
nutrients, some pump out excess
water that diffuses into a cell, others
store chemicals that contribute to cell
growth
VI. Lysosomes
A. Membrane bound sacs called
lysosomes contain digestive enzymes
that can break down such molecules
like proteins, nucleic acids and
polysaccharides
B. Lysosomes will digest food, destroy
bacteria and digest damaged
organelles
V. Membrane Pathways in a cell
A. The membranes inside a cell are
transferable from one organelle
to another
B. Products may leave a cell
without ever crossing a
membrane
Membrane pathway in a cell
6.5 Chloroplasts and
mitochondria energize cells
I. Chloroplasts
A. Chloroplasts are the photosynthetic
organelles found in some cells of plants and
algae
B. Photosynthesis is a complex, multi-step
process and the chloroplasts provides the
necessary organization for the process to take
place
C. Inside the chloroplasts are disks that act as the
“power pack”
chloroplasts
A. Chloroplasts are the photosynthetic
organelles found in some cells of plants and
algae
B. Photosynthesis is a complex, multi-step
process and the chloroplasts provides the
necessary organization for the process to take
place
C. Inside the chloroplasts are disks that act as the
“power pack”
II. Mitochondria
A. Mitochondria are structures where cellular
respiration occurs, a process that most
organisms use to access energy
B. ATP is the main energy source for the cell
and is the end result of cellular respiration
C. Mitochondria have many infoldings which
allows for a larger surface area which results
in more sites for respiration to take place
mitochondria
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
6.6 An internal skeleton supports
the cell and enables movement
I. The Cytoskeleton
A. Straight hollow tubes of proteins that
give rigidity, shape and organization
to a cell are called microtubules
B. Thin solid rods of protein that enable
the cell to move or change shape are
called microfilaments
microtubules & microfilaments
II. Flagella and Cilia
A. Flagella are long, thin whip-like
structures with a core of
microtubules that enables the cell to
move
B. Cilia are generally shorter and more
numerous than flagella and move
back and forth and moves a cell
flagella and cilia
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
III.The Cell as a Coordinated Unit
A. It is important to remember that a
cell’s organelles do not work
alone
B. The structure of a cell and its
organelles determine its function
and all the individual parts must
work together
SA 2 ( 4 pts total)
Draw a single cell.
Label the nucleus.
Is this a plant or animal cell - how do
you know?
Bonus (4 pts)
Draw one organism.
Label any visible structures.
What are the structures used for?