Transcript Diversity of Cells

Chapter 4: The Basic Units of Life
Diversity of cells
Diversity of Cells
• All living things are made up of cells.
• Robert Hooke- first person to describe cells.
He used a microscope to see cells for the first time
He saw “juicy stuff” inside the cells and also was the one of the
first to see cell membranes!
 He spent most of his time looking at plants and fungi
Plant cells have cell walls, but animal cells do not have them
Hooke thought animals were not made of cells
Diversity of Cells
Anton van Leeuwenhoek
Anton van Leeuwenhoek made his own microscope
and looked at pond scum.
 It was like looking at a city of life!
 Anton also looked at different animal blood and
was the first to noticed that different animals had
different looking blood cells.
 fish, birds, frog blood cells
are oval
 Dog and human blood cells
are flat.

Diversity of Cells
Cell Size
Most cells are small
 Some are large (page 115-Figure 2)
 Why small size for most cells?

the flatter and smaller a cell is, the more exchanged
through the cell can happen
 if the cell is big and round, the cell can’t exchange
either food or waste as efficient.

OR
Diversity of Cells
Cell Theory
Scientist Mattias Schleiden studied plants and he
helped us conclude that all plant parts were
made of cells.
 Theodor Schwann concluded that all animal
tissues were made of cells.

 Schwann
1.
2.

wrote the cell theory
All organisms are made up of one or more cells
The cell is the basic unit of all living things.
Rudolf Virchow added the third part of the cell
theory
3.
All cells come from existing cells
Diversity of Cells-Cell Size
Surface Area to Volume Ratio
The larger the surface area to volume ratio, the
better the cell can exchange nutrients and
wastes out of itself.
 Compare the two surface area to volume ratios,
which is more efficient for the cell
5 (Surface Area) 3.25 (Surface Area)
1 (Volume)
2 (Volume)
 The higher the numerator after you have
divided, the more efficient the cell

Diversity of Cells-Parts of a Cell

Cell membrane
 It
is like our skin to a cell –protects the inside
 Separates the cell’s inside with the fluid outside.
 Cell membrane controls the stuff going in and out of the
cell
 The fluid inside the cell is called cytoplasm.
 Figure 6-Page 118 in your book

Organelles
 Different
parts of the cells have different functions.
 Organelles are structures that perform specific functions
Diversity of Cells-Parts of a Cell
Genetic Material
ALL cells contain DNA-deoxyribonucleic acid
 DNA-genetic information that carries the
information to make new cells
 DNA controls the activities within those cells

 In
some cells, the DNA is inside the nucleus
(humans).
 In other cells, the DNA is not inside the nucleus
because there is no nucleus (bacteria for example)
Diversity of Cells
Two Kinds of Cells
Two Types of Cells
Cells With Nucleus
Cells without Nucleus
Prokaryotic
Eukaryotic
Eubacteria
Archaebacteria
Diversity of Cells
Eubacteria
 Most common type of prokaryote
 These type of organisms do not have a nucleus, but have
DNA
Bacteria have cell walls and ribosomes
Cell Membrane + Cell Wall = material in and out of the cell
 Bacteria are mobile by using their flagellum to motor them
around their environment.
Diversity of Cells
Archaebacteria


Similar to regular bacteria (eubacteria) in that they have
 Single-celled organisms
 Have ribosomes
 Have a cell membrane
 Have circular DNA
 Both lack a nucleus and membrane-bounded organelles
They are different than regular bacteria in that
 Ribosomes are different than bacteria
 Archaebacteria’s cell wall and cell membranes are different to
tolerate
High salt
 High heat
 Gases, like methane

Called extremophiles
Diversity of Cells
Eukaryotes


All living things that are not bacteria or
Archaebacteria have eukaryotic cells
Eukaryotic cells have
 Membrane
bound organelles
Organelles all have specific jobs in the cells
 Have a nucleus
contains the DNA of the organism
 Is one type of the membrane bound organelles mentioned
above


Eukaryotes-organisms made up of these cells
Eukaryotic Cells(the components or organelles)
 Cell
Wall
Only some Eukaryotes have these
 Plants, algae are examples
 Give structure to the cell
 Kind of like a skeleton in us, allows plants to grow
upwards and stand up.
 Fungi (yeasts and mushrooms included) have cell
walls

Diversity of Cells
Eukaryotes
 Cell Membrane

ALL cells have a cell membrane
 It protects the cell’s “insides”
 Made up of phospholipid membranes
 Lipids are “water haters”=hydrophobic
 Tail end of the cell membrane are lipids/hydrophobic
 Head is facing water-these are “water lovers” or
Hydrophilic [phosphorous end]
 The movement of materials in and out of the cell is
controlled by the cell membranes lipids and proteins.
Diversity of Cells
Eukaryotes
 Cytoskeleton
 Web
of proteins in the cytoplasm
 Acts a muscle and skeleton
 Skeleton=keeps membrane from collapsing
 Made of three types of proteins
 Hollow tube (one
type)
 Long, stringy fibers (other two)
Diversity of Cells
Eukaryotes
 Nucleus
 Large
organelle
 Contains cell’s DNA
 DNA gives the information on how to make a
cell’s proteins
 Proteins control the chemical reactions in a cell
 Surrounded by two membranes
Diversity of Cells
Eukaryotes
 Ribosomes
 Make
proteins
 Smallest of all the organelles
 Some ribosomes float freely in the cytoplasm
 Others are attached to membranes or cytoskeleton
 Proteins are made up of amino acids
Diversity of Cells
Eukaryotes
 Endoplasmic Reticulum (ER)
system of folded membranes
 Where proteins, lipids, and other materials are made
 Freeway of the cell-substances move through the ER
to different other places in the cell
 Either rough ER (make many of the cells proteins)
 Smooth ER (lacks ribosomes, makes lipids, breaks
down toxic materials that could damage the cell)

Diversity of Cells
Eukaryotes
 Mitochondria
 Power
source of the cell
 Sugar is broken down to produce energy by storing it
as ATP
 Most of the ATP is made in the mitochondria
 They have their own DNA and can divide within a cell
Outer and inner
membrane
Mitochondria at all stages
Diversity of Cells
Eukaryotes
 Golgi Complex
Packages and distributes proteins
 Looks like the ER
 Lipids and proteins from the ER are
delivered to the Golgi complex
 Contain vesicles that move into/out of or
within a cell

Diversity of Cells
Eukaryotes

Golgi complex and their Vesicles
small sac that forms from the Golgi complex’s
membrane
 like a trash truck-it surrounds material to be moved
into or out of the cell
 All Eukaryotic cells have these
 They can carry new protein from the ER to the Golgi
complex
 Vesicles distribute materials to all parts of the cells

Diversity of Cells
Eukaryotes
Lysosomes
vesicles that are responsible for digestion inside the
cells
 Found mainly in animal cells
 Vesicles engulf particles in the cells THEN
lysosomes will dump enzymes into them-digesting
them

Diversity of Cells
Eukaryotes
Chloroplasts-Plant and algae cells
 Allow
plants to produce their own food
 photosynthesis takes place
 They are green because of the chlorophyll
 Sugar produced is given to the mitochondria
to make ATP
Diversity of Cells
Eukaryotes
Vacuoles
Large vesicle in plants and fungal cells
 Act like large lysosomes
 Store and aide in digestion with in the cell
 Some vacuoles store water and liquids
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The Organization of Living Things
Benefits of being a multi cellular organism
LARGER SIZE
 Usually
larger than a single-celled organism (less worry
about predators getting us!)
 we can eat a wider variety of prey
LONGER LIFE
 Life
span is not dependent on the life span of any other
single cell.
SPECIALIZATION
 Cells
do special jobs
The Organization of Living Things
Specialization
Nerve Cell
Cancer Cells
Skeleton Muscle
Smooth Muscle
Liver Cell
Breast Cancer Cell
The Organization of Living Things
Cells Working Together
Tissue
 group
of cells that work together to perform a
specific job.
 this includes the material around and between the
cells (also part of the tissue)
Animal Tissue (4 Types)
1.
2.
3.
4.
Nerve tissue
Muscle Tissue
Connective Tissue
Protective Tissue
Plant Tissue (3 Types)
1. Transport Tissue
2. Protective Tissue
3. Ground Tissue
The Organization of Living Things
Organs
Structure made up of two or more tissues working
together to perform a specific function
 Example:
 Muscle tissues have nerves, muscle (smooth and
rough), blood vessels, ligaments, etc…

Kidney
The Organization of Living Things
Organ System
Group of organs working together to
perform a particular function
 EXAMPLE-Digestive system

The Organization of Living Things
Organism
Unicellular organism-organism made of a single
cell {Bacteria, most protists and some kinds of
fungi}
Multi cellular organism-have specialized cells
even the simplest organism
 Complex organisms are composed of cells, tissues,
organs and organ systems that perform specialized
functions.

The Organization of Living Things
Structure and Function
Structure- arrangements of parts in an
organism (includes shape and materials)
Function-job that the part does