Download 3.1 Cell Theory - Perry Local Schools

3.1 Cell Theory
KEY CONCEPT Cells are the Basic unit of life.
3.1 Cell Theory
The cell theory grew out of the work of many scientists and
improvements in the microscope.
3.1 Cell Theory
3.1 Cell Theory
3.1 Cell Theory
•
The Cell theory has three principles.
1. All organisms are made of cells.
3.1 Cell Theory
•
The Cell theory has three principles.
1. All organisms are made of cells.
2. All existing cells are produced by other living cells.
3.1 Cell Theory
The Cell theory has three principles.
1. All organisms are made of cells.
2. All existing cells are produced by other living cells.
3. The cell is the most basic unit of life.
3.1 Cell Theory
•
All cells share certain characteristics.
3.1 Cell Theory
•
All cells share certain characteristics.
1. Cells tend to be microscopic.
Bacterium
(colored SEM; magnification 8800x)
3.1 Cell Theory
•
All cells share certain characteristics.
1. Cells tend to be microscopic.
2. All cells are enclosed by a membrane.
cell membrane
Bacterium
(colored SEM; magnification 8800x)
3.1 Cell Theory
•
All cells share certain characteristics.
1. Cells tend to be microscopic.
2. All cells are enclosed by a membrane.
3. All cells are filled with cytoplasm.
cell membrane
cytoplasm
Bacterium
(colored SEM; magnification 8800x)
3.1 Cell Theory
There are two cell types: eukaryotic cells and prokaryotic cells.
3.1 Cell Theory
3.1 Cell Theory
•
Eukaryotic cells have a nucleus.
nucleus
cell membrane
3.1 Cell Theory
Eu = true
• Karyote = nucleus
• Eukaryotic cells also have membrane-bound organelles.
• Ex: All animals & plants
• Some single celled organisms
nucleus
organelles
cell membrane
3.1 Cell Theory
Prokaryotic cells do not have a nucleus.
nucleus
organelles
cell membrane
3.1 Cell Theory
•
•
•
Prokaryotic cells do not have a nucleus.
Prokaryotic cells do not have membrane-bound
organelles.
Ex: bacteria
nucleus
organelles
cell membrane
cytoplasm
3.1 Cell Theory
Differences between cells
Size – limited by ratio between their outer surface area & their volume
Shape – diversity of form reflects a diversity of function
Internal Organization – organelles – perform specific functions for the
cell
Cell
Membrane
3.1 3.3
Cell
Theory
3.3 The cell membrane is a barrier that separates a cell from the
external environment.
3.3Cell
Cell Theory
Membrane
3.1
The cell membrane has two major functions.
– forms a boundary between inside and outside of the cell
– controls passage of materials
cell membrane
3.3 Cell
Cell membrane
3.1
Theory
Homeostasis
• Cell membrane maintains a stable internal environment inside the cell
– by allowing some molecules to pass through and not others
• Selectively Permeable
3.3 Cell
Cell Membrane
3.1
Theory
The cell membrane is selectively permeable.
Some molecules can cross the membrane while others cannot.
3.3Cell
Cell Theory
Membrane
3.1
The cell membrane is selectively permeable.
Some molecules can cross the membrane while others cannot.
Cell
Membrane
3.13.3
Cell
Theory
Cell membranes are composed of two phospholipid layers.
• polar head (hydrophilic – likes water)
• 2 nonpolar tails (hydrophobic – repelled by water)
3.3 Cell
Cell Membrane
3.1
Theory
Cell Membrane – Fluid Mosaic Model – constant motion
•
•
the phospholipids move within the membrane
Proteins in the membrane also move like boats
Peripheral proteins – found on the inside & outside of the cell
Integral proteins – extend through membrane
3.3Cell
Cell Theory
Membrane
3.1
Chemical signals are transmitted across the cell membrane.
• Receptors bind with ligands and change shape.
• There are two types of receptors.
3.3Cell
Cell Theory
Membrane
3.1
Chemical signals are transmitted across the cell membrane.
• Receptors bind with ligands and change shape.
• There are two types of receptors.
– intracellular receptor – inside the cell
3.3Cell
CellTheory
Membrane
3.1
Chemical signals are transmitted across the cell membrane.
• Receptors bind with ligands and change shape.
• There are two types of receptors.
– intracellular receptor
– membrane receptor- integrated within membrane
3.3
Membrane
3.1 The
CellCell
Theory
Insights
into Cell Membrane via Dish Detergent
3.1 Cell Theory
http://www.youtube.com/watch?v=yAXnYcUjn5k&list=PL
JicmE8fK0Ehrg3meytY7DT8LJiwuU3Th&index=52
3.2 Cell
3.1
CellOrganelles
Theory
3.2 Eukaryotic cells share many similarities.
3.2 Cell
Cell Organelles
3.1
Theory
Cells have an internal structure - cytoskeleton
3.2Cell
Cell Theory
Organelle
3.1
Cells have an internal structure.
• The cytoskeleton has many functions.
3.2 Cell
3.1
CellOrganelles
Theory
Cells have an internal structure.
• The cytoskeleton has many functions.
– supports and shapes cell
3.2 Cell
Cell Organelles
3.1
Theory
Cells have an internal structure.
• The cytoskeleton has many functions.
– supports and shapes cell
– helps position and transport organelles
3.2 Cell
Cell Organelles
3.1
Theory
Cells have an internal structure.
• The cytoskeleton has many functions.
– supports and shapes cell
– helps position and transport organelles
– provides strength
3.2 Cell
Cell Organelles
3.1
Theory
Cells have an internal structure.
• The cytoskeleton has many functions.
– supports and shapes cell
– helps position and transport organelles
– provides strength
– assists in cell division
3.2 Cell
Cell Organelles
3.1
Theory
Centrioles are tubes found in the centrosomes (cytoskeleton)
3.2 Cell
3.1
CellOrganelles
Theory
•
Centrioles are tubes found in the centrosomes.
– Centrioles help divide DNA.
3.2 Cell
Cell Organelles
3.1
Theory
•
•
Centrioles are tubes found in the centrosomes.
– Centrioles help divide DNA.
– Centrioles form cilia and flagella.
Cilia & flagella assist in movement and feeding
– Cilia – short, numerous hair-like extensions
– Flagella – longer, move with a whip-like motion – cell usually only
has 1 or 2
3.2 Cell
3.1
CellOrganelles
Theory
•
The nucleus stores genetic information.
3.2 Cell Theory
3.1
Nuclear matrix – nucleus skeleton
Nuclear envelope – double membrane
Chromatin – strands of DNA
Chromosomes – formed from chromatin during cell division
Nuclear pores – small holes in the nuclear envelope
Nucleolus – site where ribosomes are formed
The
Nucleus
3.13.2
Cell
Theory
3.2 Cell
3.1
CellOrganelles
Theory
•
Endoplasmic reticulum
– Series of highly folded membranes
3.2 Cell
3.1
CellOrganelles
Theory
•
There are two types of endoplasmic reticulum.
3.2
3.1Cell
CellOrganelles
Theory
There are two types of endoplasmic reticulum.
1. Rough endoplasmic reticulum
• covered in ribosomes
makes proteins for use
outside of the cell
•
3.2 Cell
3.1
CellOrganelles
Theory
There are two types of endoplasmic reticulum.
1. Rough endoplasmic reticulum
2. Smooth endoplasmic reticulum
• makes and
stores steroids (lipids)
•
3.2
3.1Cell
CellOrganelles
Theory
•
•
Ribosomes link amino acids to form proteins.
Free floating ribosomes make proteins for use inside of the cell
cellTheory
Organelles
3.13.2
Cell
•
•
Vesicles are membrane-bound sacs that hold materials.
Found in animal cells
3.2
3.1Cell
CellOrganelles
Theory
•
•
Vacuoles are fluid-filled sacs that hold materials.
Found in plant cells
3.2
Organelles
3.1Cell
Cell
Theory
Mitochondria supply energy to the cell
3.2 Cell
3.1
CellOrganelles
Theory
Mitochondria
Cell respiration - transfer Energy (E) from
organic compounds (food) into ATP
(cellular E)
-Cristae – folded inner membrane
-Increases the surface area
-Increases E production
3.2 Cell
Mitochondria
3.1
Theory
3.2 Cell
3.1
CellOrganelles
Theory
Golgi Apparatus – processes, packages, & secretes substances
3.2 Cell
Cell Organelles
3.1
Theory
•
Lysosomes contain enzymes to digest unwanted or broken material.
3.2
Organelles
3.1Cell
Cell
Theory
Plant cells have cell walls and chloroplasts.
• A cell wall provides rigid support.
3.2 Cell
Cell Organelles
3.1
Theory
3.2 Cell
3.1
CellOrganelles
Theory
Plant cells have cell walls and chloroplasts.
• A cell wall provides rigid support.
• Chloroplasts convert solar energy to chemical energy (photosynthesis)
• Thylakoids – stacks of sacs filled with chlorophyll
Increase surface area - increase photosynthesis
3.2 Cell
Cell Organelles
3.1
Theory