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1
Units Goals
Analyze the nature of the relationships between
structures and functions in living cells.
1. Explain the role of cell organelles
for both prokaryotic and eukaryotic
cells.
•
Including the cell membrane, in maintaining
homeostasis and cell reproduction.
2. Explain the impact of water on life
processes.
•
Osmosis and diffusion
2
What is a cell?
All living things
are made of
small structures
called cells.
HISTORY
OF THE
CELL
3
Robert Hooke
• One of the first people to
see cells.
• Looked at Cork Cells.
• First to use the word
cells- named them for
the places that
monks sleep in
the monastery.
1665
cork
1839
5
Theodor Schwann
Concluded
that all
animals are
made up of
cells
1839
6
Matthias Schleiden
Concluded that
all Plants are
made up of
cells
Clip
7
Cell Theory
• All living things are
made up of cells
• Cells are the basic unit
of structure and
function in living things
• All cells come from preexisting cells
• Clip
7
What is a cell made of?
Cells are ~90%
water.
8
Cell Composition
Of the dry weight:
•
•
•
•
•
50% protein
15% carbohydrate
15% nucleic acid
10% lipid
10% miscellaneous
Approximate composition
by element:
•
•
•
•
60% H
25% O
12% C
5% N
What are
the two
basic types
of cells?
8
9
Prokaryotic Cells
DO HAVE
DO NOT HAVE
• Cell membrane • Organelles
• Ribosomes
• Nucleus
• DNA
•Are all singled celled
organisms--ex: Bacteria
•Thought of as more ancient life
forms…they came first.
•They still carry out all of life’s functions!
10
Eukaryotic Cells
• Have organelles.
• Believed to have
evolved from
prokaryotic cells
(Theory of
Endosymbiosis).
• Can be singledcelled or multicellular
organisms.
– ex: plants, animals,
fungi, protista
11
How big are cells?
Major Theme
• “Function dictates
form”
• Humans have ~200
cell types
• All cells do not
look alike
– Ex: Nerve cells
long and spindly
– Cells that store
fat are rounded
&large
– Structural cells
are square
11
Size differences:
Pro: .1-10 μm
Eu: 10-100 μm
Animation
•Cells come in many
different shapes & sizes.
12
How are
cells
organized?
Basic Cell
Structure
The Cell Membrane
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(aka: plasma membrane)
• The outside of all
cells are surrounded
by a membrane made
of phospholipids.
• Nickname: “The gatekeeper”
Selectively Permeable (Semi-permeable
Membranes are fluid
14
about as
fluid as
salad oil
• Membrane molecules are held in place by
relatively weak hydrophobic interactions.
• Most can drift laterally, but rarely flip-flop from
one layer to the other.
15
Plant and Fungi cells also have a cell wall
outside of the cell membrane.
Plant cell wall are
made of Cellulose.
Fungi cell walls are
made of Chitin.
16
• Cell walls can also be
found in fungi and
bacteria.
• The cell wall provides
support and
protection for these
cells.
• In plants, the cell
wall is made of the
carbohydrate
cellulose.
Paramecium & Elodea Leaf
Inside of the cell
The Cytoplasm
19
The cytoplasm contains all
of the organelles in
eukaryotic cells.
20• Cells are filled
with organelles
that each do
something to keep
the cell alive.
• The jelly-like
insides of a cell is
called cytoplasm.
21
Organelles in the Cytoplasm
• Each organelle has a specific
function so that the cell can do
its job.
• Each organelle has its own job!
• Remember: ONLY EUKARYOTIC
CELLS HAVE ORGANELLES!!!!
22
What an organelle?
• Organelle means “tiny organ.”
• Organelles function together to
help the cell carry out all of
life’s activities!!
23
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Nucleus-The Control Center
• The “Brain”
• Contains the
DNA
• DNA controls
which proteins
get made-and
when!
• Where
ribosomes are
made
25
•
The nucleus has a
phospholipid
bilayer around it.
• The nuclear pores
allow substances
to move into and
out of the
nucleus.
• The DNA NEVER
leaves the
nucleus.
27
Ribosomes
• Not technically an
organelles.
• Nickname: “protein
maker”
• Place where proteins
are made.
• They help put the
amino acids together
to make proteins.
• Made of the nucleic
Acid-RNA
• website
29
Endoplasmic Reticulum
• Membrane
system
that’s
function
involves
protein
synthesis
and
transport.
• Can be
thought of
as a
highway
and a place
of protein
synthesis.
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1. Smooth
Two types of ER
– No attached
ribosomes
2. Rough
– Attached ribosomes
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ER branches
off from
the nuclear
membrane.
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Golgi Apparatus
• Nickname: “UPS”
• Packages molecules and
sends them to their
destination.
• Also checks to make sure
the molecules are put
together correctly, if not
correct it sends them
back to the ER.
• Website
p. 175
Animation
35
Golgi w/vesicles
Vesicles are
packages of
material that
are being
transported.
Lysosomes
36
• Nickname “Recycling Center”
• Has digestive enzymes that breakdown
and recycle molecules.
• Old cell parts
• Invaders
Vacuoles
37
Storage and transport containers.
• Plants usually have one large vacuole.
• Animals generally have many small ones.
• A vacuole is a membrane-bound sac that
plays roles in intracellular digestion & the
release of cellular waste products.
When used for Transport:
Sometimes known as vesicles.
• Vacuoles play a role in
turgor pressure in plant
cells.
– When a plant is wellwatered, water collects in
cell vacuoles producing
rigidity in the plant.
– Without sufficient water,
pressure in the vacuole is
reduced and the plant wilts.
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Chloroplasts
•Site of
photosynthesis
in plants and
some protists.
•Requires
sunlight.
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Mitochondria
• Nickname:
“Powerhouse”
• Helps breakdown
glucose for energy.
• Site of ATP
production
– ATP is the universal
energy molecule
– Energy is stored in
the bonds of ATP.
• Website
42
Cytoskeleton
• Gives cells their
shape.
• Contain proteins: microtubules
and microfilaments.
– Microfilaments help give the cell shape, and
movement in cytoplasm.
– Microtubules
aids in
chromosome movement, movement
of organelles, cilia and flagella.
– Without the cytoskeleton, the cell would have no
shape. By allowing the cell to keep shape, the cell is
allowed to function and stay in homeostasis.
43
Microtubules and Microfilaments
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Cell membrane
Endoplasmic
reticulum
Microtubule
Microfilament
Ribosomes
Michondrion
Now it’s your turn!!!
Smart board
Review
Animal cell
Animal Cell and Plant Cell
Clip
48
Levels of Organization in Organisms
•
•
•
•
Cells make up tissues.
Tissues make up Organs.
Organs make up organ systems.
Organ Systems make up organisms.
49.1
How do
things get
into and out
of cells?
49.2
The Cell Membrane
(aka: plasma membrane)
• Cells need to get molecules
into and out of the cell in
order to live.
• They need to get “food” molecules in and
“waste” molecules out.
• Membrane Video Clip
50
The Cell Membrane
• Hydrophilic: water loving
• Hydrophobic: water fearing
• The hydrophobic
interior inhibits the
movement of ions.
• The membrane can
control the
movement of
molecules (maintaining
homeostasis).
Diffusion across the membrane
• Some molecules
like H20, C02
and O2 can move
(diffuse) directly
across the
membrane.
51
C02
C02
C02
02
C02
02
02
•What determines which way
they will go…in or out???
Concentration
Diffusion
52
•Movement of
molecules from
The universe WANTS equilibrium!!
a place of
higher
concentration
to a place of
lower
concentration
•Always higher
to lower!
•No energy
input required!
Osmosis is a special case of diffusion
53
Osmosis: Diffusion of water through a cell membrane
HL…No energy input required!
66
Solutions
When 2 or more substances are mixed
together.
67
3 types of Solutions
1.Hypotonic
2.Hypertonic
3.Isotonic
Hypotonic
68
Beaker
of
water
and
sugar
Cell
Grows
larger.
CELL
solute
The solution with the lower
concentration of solutes is hypotonic
69
Cell
Stays
the
same
size.
Isotonic
Beaker
of
water
and
sugar
CELL
Solutions with equal solute
concentrations are isotonic
solute
70
Hypertonic
Beaker
of
water
and
sugar
Cell
shrinks.
CELL
solute
The solution with the higher
concentration of solutes is hypertonic
71
Hypertonic, hypotonic, isotonic
–These are comparative
terms.
•Tap water is hypertonic
compared to distilled water
but hypotonic when
compared to sea water.
72
3 types of Solutions
73
What types of solution?
Hypertonic Or Hypotonic
74
Plasmolysis
Cell membrane
shrinks away
from the cell wall
Hypertonic
Turgor Pressure animation
Plasmolysis
75
Review Clip
Question:
Why could it be deadly if you
drank sea water?
What about
substances that
can’t diffuse
through the
phospholipid
bilayer?
54
Basic Cell
Structure
Membrane Structure
55
There are proteins “stuck” in the membrane
that help get molecules & messages into and
out of the cells.
Proteins in Membrane 56
-help get molecules & messages into and out of the
Basic Cell
Structure
cells.
57
Proteins in Membrane
Remember Goal #1
Function of cell
membrane in
maintaining
homeostasis.
-The proteins
allow things in
and out!
-We say that
the membrane
is “selectively
permeable” or
“semipermeable”
54
Facilitated Diffusion
-When molecules
pass through a
protein in the
membrane it is
called facilitated
diffusion.
special case of diffusion
NOT
Protein
Energy is
required to move
substances across the membrane.
This is simple diffusion… HL
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Facilitated Diffusion
High
Concentration
Cell Membrane
bilayer
Glucose
molecules
Protein
channel
Low
Concentration
You Tube
56
What if a cell needs to
take in or get rid of
molecule against the
concentration gradient
(Low to high) ?
57
Active Transport
• Cells can
pump large
amounts of
some
molecules.
• This takes
ENERGYATP.
• LH
•Going against the
concentration gradient.
58
Active Transport
• Energy is
required.
• Need ATPthe universal
energy
molecule.
• Low to high
57
You Tube
60
Transport through the membrane
-Simple
diffusion
• Energy input
NOT
required
• High to low
-Osmosis
• Energy input
NOT
required
• Water
• High to low
– Facilitated Diffusion
• Energy input NOT
required
• Movement through a
protein
• High to low
– Active Transport
• Energy input required
• Movement through a
protein
• Low to high
Transport Review Animations
Energy Required
No Energy Required
61
Other ways to get
molecules into and out of
a cell
Some molecules are too large to
get through the membrane.
Website
1. Endocytosis
• Into the cell
2. Exocytosis
• Out of the cell
You tube Clip
Endocytosis
Into the cell
E
N
D
O
C
Y
T
O
S
I
S
62
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64
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Inside of the cell
Exocytosis
Outside of the cell
• Review Transport
76
Microscopes
77
Stage
10x Objectives
Eyepiece
Oil lens
Arm
Base
100x Objective
Body Tube
Nosepiece
Diaphragm
Light Source
Fine Adjustment
Coarse Adjustment
Stage Clips
78
Robert Hooke
• Late 1600s
• Microscope
79
80
Electron Microscopes
• Use a beam of highly energetic electrons to
examine objects on a very fine scale
• Co-invented by Germans, Max
Knott and Ernst Ruska in 1931,
Ernst Ruska was awarded half of
the Nobel Prize for Physics in 1986
for his invention.
• 15x to 200,000x
81
Below are five different images of the same mosquito.
82
• The fossilized
shell of a
microscopic ocean
animal is
magnified 392
times its actual
size. The ancient
creature, called
Radiolarian, lived
in the waters off
Antarctica and is
now used to study
such things as
climate and ocean
circulation.