Transcript Inner life of a cell http://www.aimediaserver.com

Inner life of a cell
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Section 3-2 (pages 55-60)
Cell Features
Objectives:
1. List the three parts of the cell theory. (pg.
55)
2. Determine why cells must be relatively
small. (pg 55)
3. Compare the structure of prokaryotic cells
with that of eukaryotic cells. (pg. 57)
4. Describe the structure of cell membranes.
(p. 59)
Key Terms
Cell Theory
Cell Membrane
Cytoplasm
Ribosome
Prokaryote
Cell Wall
Flagellum
Eukaryote
Nucleus
Organelle
Cillium
Phospholipid
Lipid Bilayer
What are the three parts of the
Cell theory
1. All living things are made up of cells.
2. Cells are the basic units of structure
and function in organisms.
3. All cells arise from existing cells.
Antony van Leeuwenhoek (1632-1723)
Why Must Cells be Small?
If the cell’s surface area-to-volume ratio is
too low, substances cannot enter and
leave the cell in numbers large enough to
meet the cell’s needs.
substances do not need to travel as far to reach
the center of a small cell
What Features are Common of
cells?
Cell membrane
Cytoplasm
Cytoskeleton
Ribosomes
What is the Cell Membrane (plasma
membrane)
Cell Membrane: is the outer boundary layer
of the cell, made up of phospholipids. It
regulates what enters and leaves a cell –
including, gases, nutrients, and wastes.
What are phospholipids
• A phospholipid is a lipid made up of a
phosphate group and two fatty acids.
• It has a hydrophilic head (water loving)
and a hydrophobic tail (water hating)
What is the lipid bilayer
• In a cell membrane, the phospholipids
are arranged in a double layer called a
lipid bilayer.
• The nonpolar (water hating) tails make
up the interior of the bilayer, and the
polar (water loving) heads make up the
outer layer.
Cytoplasm
Cytoplasm: The interior of the cell which
houses many organelles and cellular
structures.
Cytoskeleton
A system of microscopic fibers (tubules),
inside the cytoplasm, that many
organelles are suspended from.
Ribosome
Ribosome: Cellular structures on which
proteins are made.
What is a Prokaryote (Bacteria)
• Prokaryotes are the smallest and
simplest cells
• They are singled celled organisms that
lack a nucleus, cytoskeleton, and other
internal compartments.
What are the Characteristics of
Prokaryotes (Bacteria)
• Bacterium’s enzymes and ribosomes are
free to move around in the cytoplasm
because they lack internal
compartments.
• Bacteria have a cell wall providing
structure and support
• Some bacteria have a flagella, long
threadlike structures that enable
movement.
What are Eukaryotes
• Eukaryotes are organisms whose cells
have a nucleus, other internal
compartments, and organelles.
What are Organelles
• An organelle is a structure that carries out
a specific function in the cells.
What organelles are found only in
Eukaryotes
Nucleus
Mitochondria
Chloroplasts
Cytoskeleton
Vacuole
Golgi bodies
Lysosomes (vesicles)
Smooth endoplasmic reticulum
Rough endoplasmic reticulum
The Eukaryotic Nucleus
The nucleus is a membrane bound internal
compartment that houses the DNA
What is the Form and Function
of the
DNA molecule
Form: A double helix (looks like a twisted
extension ladder)
Function: Stores the hereditary
information that controls all cell
processes.
What is the Form and Function
of the
Mitochondria?
Form: A kidney shaped organelle floating
around in the cytoplasm, with a set of
internal folding membranes.
Function: It converts the energy stored
in food compounds into a useful form,
called ATP (adenosine triphosphate)
Form and Function of the
Endoplasmic Reticulum (ER)
Form: A network of lipid bilayer
membranes.
Function: Moves proteins and other
substances through the cell
What does the Rough ER do?
Contains ribosomes on its surface and
makes proteins. It also makes new
membranes
What does the Smooth Endoplamsic
Reticulum do?
Makes lipids, Also processes
carbohydrates and modifies toxic
chemicals in the cell
What is the Form and Function
of the
Golgi Apparatus?
Form: Flat pancake like sacs
Function: It’s the post office the cell. It
makes vesicles, such as lysosomes; that
store, sort, changes, packages, and
distributes proteins throughout the cell.
What is the Form and Function
of Lysosomes?
Form: Made by the Golgi Apparatus.
Small spheres floating around the
cytoplasm that contain digestive
enzymes
Function: Lysosomes break down bacteria
viruses, and non functional organelles
within the cell.
Often nicknamed “suicide bags”
Vacuoles
Cell Walls
Chloroplasts
What is the Form and Function of
Vacuoles?
Form: Sacs that are often found in plants
cells
Function: They absorb water, store
proteins, ions and waste products.
What is the form and function of
Cell walls?
Form: A tough ridged outer covering that
surrounds the cell membrane of plants
and bacteria cells.
Function: It protects the plant cell and
give it shape.
What is the Form and Function
of
Chloroplasts?
Form: Green oval-shaped structures
Function: enable plants to make sugars
through photosynthesis
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