Transcript Cells and Cell Theoryx

THE CELL AND CELL THEORY
WHAT IS BIOLOGY?
Bio
= “Life”
Ology
= “the study of”
Create
a list in you notes titled:
Etymology
Etymology
= “study of word origins”
Etymology
website: Etymonline
HOW DO WE KNOW WHAT IS LIFE/LIVING?
Characteristics
Brainstorm
of life/living things:
and create a list of
things that all living things have in
common.
CHARACTERISTICS OF LIFE/LIVING THINGS:
 1.
Made of cells
 2. Reproduce
 3. Grow and develop
 4. Make or use “food” energy
 5. Sense and react to their environment
 6. Based on a universal genetic code DNA or RNA
 7. Maintain stable internal environment (a.k.a.
homeostasis)
 8. As a group. Change over time (a.k.a. adapt/evolve)
 *When
considering these, be careful not to be
too anthropocentric in your thinking.
PARTS OF THE CELL
Plant and animal cells have
many membrane bound
organelles that help these
cells perform all of the
necessary jobs.
CELL ORGANELLE ASSIGNMENT:
( SEE PG 174-)
 Fill
in the chart for each organelle and/or cell
structure:
 1)
Cell membrane
 4)
Chromosomes 5) Nucleolous
 7)
Endoplasmic reticulum
 9)
Golgi bodies 10) Lysosomes
 12)
Vacuoles
 15)
Cytoskeleton
2) Cytoplasm
13) Cell wall
3) Nucleus
6) Ribosomes
8) Mitochondria
11) Centrioles
14) Chloroplasts
Name:
Cell
membrane
Cytoplasm
Nucleus
Chromosomes
Nucleolous
Found in:
Function:
Nickname:
Sketch:
ENDOSYMBIOTIC THEORY:
See
pgs 180 and 427-428.
Summarize
what the theory says
and provide a sketch to
illustrate. Be sure to include the
evidence for this theory.
ENDOSYMBIOTIC THEORY (A.K.A. ENDOSYMBIONT HYPOTHESIS):



-Chloroplasts and mitochondria were once free-living,
primitive organisms with an “early/primitive
nucleus”(Prokaryotic).
-Also around at this time were cells with a “true nucleus”
(Eukaryotic).
-The prokaryotic organisms were “taken in” by the more
advanced cell(s).
-Inside the new cell, the prokaryotes became incorporated
into the functioning of the eukaryotes, allowing it/them to
complete the following processes:
 a) photosynthesis, (due to the chloroplasts)
 b) cellular respiration, a.k.a. “breathing to produce energy”
(via mitochondria)

 -The
newly incorporated organisms were now
acting as organelles (mini-organs) for a host
cell.
 -Cells
which took in both types became plants
and plant-like protists; those taking in only
mitochondria became animals, fungi, and non
plant-like protists.
 -Both
types of cells/organisms now living
together in a symbiotic relationship.
ENDOSYMBIOTIC THEORY (A.K.A. ENDOSYMBIONT HYPOTHESIS):
Evidence for this idea:
 Both Mitochondria and chloroplasts have:
 Plasma membranes (a.k.a. cell membranes) very similar
to those of free living prokaryotes today.
 Their own DNA, and that DNA is similar to bacterial
DNA (bacteria are prokaryotes).
 Their own ribosomes and those ribosomes are similar to
those of bacteria.
 Divide and reproduce similar to the way that bacteria do
(by binary fission).
 There are more pieces of evidence but it gets much more
detailed and specific. Is this enough to convince you?

TYPES OF CELLS:
Prokaryotic Cells:
Lack a nuclear membrane
 Ex: Bacteria and BlueGreen Algae

Eukaryotic Cells:
Have a true nuclear
membrane
Ex: Plant, animal cells

THE DEVELOPMENT OF CELL THEORY (PG 170):
 Aristotle
(334 BCE):
Living things could spontaneously
generate from non living or dead
things. (a.k.a. abiogenesis)
(Ex: maggots and mushrooms grow on
rotting organisms, frogs fall with rain)
Janssen (1590):
Eyeglass maker, created first
microscopes.
Robert Hooke (1665):
Discovered and named cells
by looking at cork under
microscope.
 Anton
van
Leeuwenhoek (1674):
Discovered tiny organisms
in pond water.
THE DEVELOPMENT OF CELL THEORY:
 Schleiden
and Schwann (1838-39):
Using microscopes, declared all plants and all animals
to be made of cells.
 Virchow
(1858):
Stated that all cells come from pre-existing cells.
 Louis
Pasteur (1864):
Uses experiments similar to Redi and Spallanzani to
disprove spontaneous generation once and for all.
(pgs 11 and 12)
THE CELL THEORY:
1.
All living things are made of cells.
2.
Cells are the basic unit of life.
3.
All cells come from existing cells.
CELL BOUNDARIES AND TRANSPORT (182-189):
1. What are the functions of the cell membrane?
 2. What do we call the double layered sheet that forms the
core of nearly all cell membranes?
 3. What is the difference in function of the proteins and the
carbohydrates attached to a cell membrane?
 4. In what organisms are cell walls found?
 5. What are plant cell walls mostly made of?
 6. What do we mean the ‘concentration of a solution’?
 7. What is diffusion?
 8. What does it mean when we say that a system has
reached equilibrium?
 9. What does it mean when we say that biological membranes
are selectively permeable?
 10. What is osmosis?

11. Looking at figure 7-15 on page 185, answer the following
questions?
 a) In the beaker on the left, which solution is hypertonic and
which is hypotonic? (left solution vs right solution).
 b) In this model, to which material is the membrane
permeable, water or sugar?
 c) Draw a third beaker which would show two solutions (left
and right) which are isotonic.
 12. What happens in the process of facilitated diffusion?
 13. What is the role of protein channels in the cell
membrane?
 14. What is active transport?
 15. What is the difference between active transport and
facilitated diffusion?
 16. Describe each of the following forms of active transport:
 a) endocytosis, b) phagocytosis, c) pinocytosis, d) exocytosis

The cell membrane:
-gatekeeper
-controls movement of
materials in and out of the
cell.
The cytoplasm:
-jelly-like
-supports organelles
-where nutrients are absorbed,
transported and processed and
wastes are stored before disposal
The nucleus:
-control center for cell functions
-storage center for the instructions of
life (DNA).
Chromosomes:
-thread-like structures that
carry the genetic information.
-DNA/genes
(found in the nucleus)
The nucleolus:
-darker area found inside the
nucleus
-involved with the synthesis of
proteins
Ribosomes:
-build proteins essential for cell
growth and reproduction
-the proteins make up all cell
structures
The endoplasmic reticulum:
-canals that transport
materials to different parts of
the cell.
Mitochondria:
-where cellular respiration takes
place and energy is provided to the
organism.
Golgi bodies:
-package and store proteins
Lysosomes:
- contain enzymes which help break
down food and digest waste and
worn out cell parts.
Centrioles:
-needed for cell
division in
animal cells
Vacuoles:
-fluid-filled storehouses
that contain water, food,
wastes, and other
materials.
Cell wall:
-provides protection and support for
the plant cell.
Chloroplasts:
-production and storage of food in
plant cells.
-Contain chlorophyll, specialize in
photosynthesis.


Cytoskeleton – a network of protein filaments that give
a cell its shape
Microtubules and microfilaments make up the
cytoskeleton
Flagella are thread-like fibers (tails) that
propel certain cells (ex. sperm)
Microfilaments are pipe-like structures that
help provide shape and movement for the
cells. They are like the rebar that are placed
on a garage floor before pouring cement
Microtubules are tiny threadlike
fibers that transport materials
throughout the cytoplasm.
Each chromosome contains many different
genes. Genes are units of genetic
information that determine the specific
characteristics of an individual.
TYPES OF ENDOPLASMIC RETICULUMS
1)
2)
Rough Endoplasmic Reticulum (RER) – has
many ribosomes attached to the canals. These
ribosomes synthesize proteins. RER is
predominant in cells that specialize in secreting
proteins
Smooth Endoplasmic Reticulum (SER) – is
free of ribosomes and is found in the areas in
which fats or lipids are synthesized.