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Cell
Biology
Cell
Essential Question
Name those who added to
the cell theory;
what did each contribute?
10.29.2007
Cell
Cell Theory
• Robert Hooke (1665)
– first discovered and
named “cells”
– looked at dead cells
of a cork plant
Cell
Cell Theory
• Anton van Leeuwenhoek (1674)
– built microscopes to study
‘animalcules’ known today
as microorganisms
– first to see living cells
Cell
Cell Theory
• Matthias Schleiden (1838)
– stated all plants are made of cells
Cell
Cell Theory
• Theodore Schwann (1839)
– studied human notochord
– concluded all animals are made of cells
Cell
Cell Theory
• Rudolph Virchow (1858)
– every cell comes from another cell like it.
Cell
Cell Theory
• modern Cell Theory
– All living things are composed of
cells.
– Cells are the units of structure and
function in living things.
– New cells are produced from
pre-existing cells.
Cell
Cell Structure
• Cells can come in 3 shapes
1. Sphere
2. Brick
3. Cube
Cell
Cell Structure
The smallest are bacteria cells
The largest is the human egg
Cell Structure
• Two types of organisms
1. Unicellular- ex. Bacteria,
yeasts, Amoeba
2. Multicellular- some cells are
specialized; evolved from
unicellular cells
Cell
Cell Structure
• Levels of organization
cell
tissue
organ
organ system
organism
Cell
Cell
Organelles
cell membrane
Cell
Organelles
(transparent
layer
between
cells)
cell wall
Cell
Organelles
nucleus
Cell
Organelles
(stained green)
microtubules
Cell
Organelles
microfilaments
Cell
Organelles
(red)
ribosome
Cell
Organelles
(yellow)
endoplasmic reticulum
Cell
Organelles
(purple)
golgi apparatus
Cell
Organelles
lysosome
Cell
Organelles
vacuole
Cell
Organelles
mitochondria
Cell
Organelles
flagella
Cell
Organelles
cilia
Cell
Organelles
(green)
chloroplast
Cell
Organelles
(green)
cell wall
Cell
Organelles
centriole
Cell
Organelles
(white)
cytoplasm
Organelles
What is a plastid?
A storage cell
Which 3 organelles are plastids?
Cell
Cell
Essential Question
What are the different states
of concentration across a
membrane?
11.5.2007
Cell
Types of cells
• cells classifications
– prokaryote
• no membrane bound organelles (no
nucleus)
ex: bacteria
– eukaryote
• cells with membrane bound
organelles
ex: plants, fungi, animals, protists
Cell
Transport
• cell membrane
– fluid mosaic model
• membrane constantly moving
– 3 main molecules
• proteins
• carbohydrates
• lipids
– hydrophilic (water loving) heads
– hydrophobic (water fearing) tails
Transport
Cell
Cell
Transport
• cell membrane
– allows for transport of materials into
and out of cell
Cell
Transport
• diffusion
– movement of molecules from higher to
lower concentration
Cell
Transport
• equilibrium
– state in which concentration is equal in
all areas
Transport
• osmosis
– movement of water from higher to
lower concentration.
Cell
Cell
Transport
•
osmosis
– hypertonic
• concentration of solute is greater outside
cell
– hypotonic
• concentration of solute is less outside cell
– isotonic
• concentration of solute is equal on both
sides of membrane
Transport
• osmosis
Cell
Transport
• osmosis
Cell
Cell
Transport
• osmosis
Which is isotonic, hypertonic, hypotonic?
Isotonic
hypertonic
hypotonic
Transport
• osmosis
Cell
meaning concentration percent water moves
of name of solute
of water into/out of cell
(compared
to cell)
hyper
hypo
iso
(compared
to cell)
Transport
• osmosis
Cell
meaning concentration percent water moves
of name of solute
of water into/out of cell
hyper more
hypo
iso
(compared
to cell)
(compared
to cell)
higher
lower
out of cell
Transport
• osmosis
Cell
meaning concentration percent water moves
of name of solute
of water into/out of cell
hyper more
hypo less
iso
(compared
to cell)
(compared
to cell)
higher
lower
lower
higher
out of cell
into cell
Transport
• osmosis
Cell
meaning concentration percent water moves
of name of solute
of water into/out of cell
hyper more
hypo less
iso
same
(compared
to cell)
(compared
to cell)
higher
lower
same
lower
higher
same
out of cell
into cell
both directions
Cell
Essential Question
Be able to differentiate
between the types
of cell transport.
11.7.2007
Cell
Transport
• facilitated diffusion
– molecules move across membrane
with help of transport proteins
Cell
Transport
• active transport
– uses energy to transport molecules
against concentration gradient
Cell
Transport
• active transport
– uses energy to transport molecules
against concentration gradient
Cell
Transport
• endocytosis
– engulfing solid particles using the cell
membrane
Cell
Transport
• endocytosis
– engulfing solid particles using the cell
membrane
1. phagocytosis
•
endocytosis of solid material
2. Pinocytosis
•
Endocytosis of liquid material
Transport
• exocytosis
– cell secretes large particles via
membrane bound sacs
Cell
Transport
Cell
Tugor: the pressure within cells derived
from osmotic pressure differences
between the inside and outside of the
cell causing rigidity.
Evolution of eukaryotic cells
Prokaryotes were the 1st to evolve, then
eukaryotes
Why??
Cell
Evolution of eukaryotic cells
Cell
Symbiotic Theory: prokaryotes were once engulfed by
other cells, giving rise to eukaryotes.
1. Ex. Mitochondria and Chloroplasts have their own
DNA and RNA
Evolution of eukaryotic cells
mitochondria are the result of endocytosis of aerobic
bacteria
chloroplasts are the result of endocytosis of
photosynthetic bacteria
Cell