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Chapter 7 Cells and Transport
Hooke 1665
 Observed
pieces of cork under a simple
microscope.
Describe the structure of cork.
•Hooke named the structures “CELLS”.
•He named them after the rooms that monks lived in
at monasteries, because they looked like empty
rooms.
Leeuwenhoek 1674
•He used a primitive microscope
to look at many objects.
•He saw tiny creatures swimming
around and called them
“animalcules”.
Schleiden 1838
 Concluded
that all
plants were made
of cells.
→
Schwann 1839
 Concluded
that all
animals were made
of cells.
→
Virchow 1855
 Proposed
that all
cells must come
from existing cells.
The cell theory
1st States that……..
ALL
LIVING
THINGS ARE
COMPOSED OF
CELLS.
2nd States that….
CELLS
ARE THE BASIC
UNIT OF STRUCTURE
AND FUNCTION IN
LIVING THINGS.
3rd and Finally states that…..
NEW
CELLS ARE
PRODUCED FROM
EXISTING CELLS.
Let’s look at some cells!
List at least 5 differences between
these two types of cells.
Prokaryotes vs.
Eukaryotes
 Prokaryotes
– Smaller, more primitive cells.
Lack a nucleus and organelles.
Examples: Bacteria and cyanobacteria
 Eukaryotes
– “True nucleus”. Have
membrane-bound DNA and complex
organelles. Examples: Animals, plants,
fungi, protists (amoeba).
Eukaryotes vs. Prokaryotes:
Size
A macrophage eating E. coli and human cheek cells with bacteria.
Plant and Animal Cells
Plant cells have:
 A cell wall
 Chloroplasts
 No centrioles
 Large vacuoles
(some)
Animal cells have:
 No cell walls
 Centrioles
Plant and Animal
cells have:
•Mitochondria
•Cell membranes
•Nucleus
•All other organelles
Cellular Organelles:
Organelles found in Eukaryotes
Cell membranemade of a phospholipid bi-layer, the
membrane protects
the cell and regulates
what enters and exits
the cell
illustrations:
Endoplasmic
Reticulum:
 An
extension of the
nucleus inside the
cell, the ER
transports materials
inside the cell and
serves as a place
for protein synthesis
(Rough ER).
 Ribosomes: sites of
protein synthesis.
Golgi Body:
 “flattened
pancakes” that
take material
traveling on the ER
and package it and
label it for
intracellular or
extracellular
transport.
Nuclear
membrane:
 Surrounds
the
nucleus and has
pores which allow
RNA to pass through
the cytoplasm
 Regulates protein
messages to the rest
of the cell
Nucleus:
 Contains
the DNA
on chromosomes.
Site of the
replication of DNA
in the beginning of
mitosis.
Mitochondria:
 The
“powerhouse” of
the cell.
Mitochondria are
kidney bean/oval
shaped with a wavy
internal membrane.
ATP (the cell’s energy
currency) is formed
on this membrane.
(Once bacteria??)
Chloroplast:
 Found
only in plants,
chloroplasts are
oval shaped
organelles that
gather the sun’s
energy to create
ATP and assemble
carbohydrates for
plants to use in the
future.
Cell Wall:
 Also
found only in
plants (and fungi),
the cell wall is a
rigid structure made
of cellulose and
lignin that protects
a plant cell and
gives it shape.
Peroxizomes:
 Small
vesicles
(bags) that contain
various enzymes
that convert fats to
carbohydrates and
convert H2O2 into
water and oxygen.
Lysosomes:
 Vesicles
that
contain digestive
enzymes.
Vacuole:
A
large internal
storage place for
wastes, food, or
water. Common in
plant cells.
Cytoskeleton:
 The
internal
framework of the
cell composed of
microtubules that
give the cell its
shape.
Centrioles:
 Found
only in
animal cells, the
centrioles set up the
framework that
moves the
chromosomes to
opposite sides of
the cell during cell
division.
Flagella and Cilia:
 Flagella:
Complex
cables of
microtubules that
allow for cellular
movement.
http://www.microscopyu.com/m
oviegallery/pondscum/protozoa/
peranema/t1/peranema03.html
 Cilia:
Smaller, more
numerous flagella in
a large area of the
cell.
http://www.microscopyu.com/moviegallery/pondscum/protozoa/stentor/t1/stentor0
1.html
Cellular Organelles:
 Organelles
work together to allow the cell
to carry out important life functions.
 Use your notes and your diagrams to help
you study.
 Complete your cell models/activities for
side dishes. Include: cell membrane,
nucleus, nuclear membrane, rough ER,
smooth ER, Golgi body, mitochondria,
lysosomes, and centrioles.
The cell membrane regulates
what enters and exits the cell.
Active
transport – the movement
of particles across the membrane using
energy (ATP). Examples: gated channels,
endocytosis, etc..
Passive
transport – the movement
of particles without using additional
energy. Examples: osmosis, diffusion.
A review:
Solution – a mixture of two or more
substances
Solutes – the substances dissolved in
the solution.
Water – the universal solvent.
Concentration – the mass of
solvent in a given volume of solution.
Passive transport:

Diffusion – the movement
of particles from an
area of high
concentration to an
area of low
concentration. When
the concentration of
the solvent is even
throughout, the system
has reached equilibrium.
 Simulation in cells
Passive transport, continued…

Osmosis – the diffusion

Selectively permeable –
of water through a
selectively
permeable
membrane.
some particles can
pass through while
others cannot.
 Water wants to reach
an equilibrium!
 animation
Osmosis continued…
 Water
moves to “dilute” out the more
concentrated solution so the free water
content is equal on both sides of the
membrane.
 Isotonic solution – when the amount of solutes
and water is the same on both sides of the
membrane. Example: RBC’s and plasma.
 Hypertonic – more concentrated solution.
Example: Salt water.
 Hypotonic – the less concentrated solution.
Example: Red blood cell in salt water
Red blood cells in various
solutions:
Passive transport, Continued…
 Facilitated
diffusion –
Protein channels in the
cell help certain
molecules (glucose)
through the
membrane.
 No energy used.
 Animation
 What diffuses?
Water, oxygen,
carbon
dioxide, glucose…
Active
Transport:
 Endocytosis – Uses ATP to “engulf” or take in
food/water through the cell membrane.
Examples:
Pinocytosis – taking in water by
pinching in around it.
Phagocytosis – taking in food/solids
by pinching in.
 Exocytosis- Uses ATP to expel vesicles
(proteins, solids)