Transcript The Diversity of Cells

The Diversity of Cells
Chapter 3: Section 1
Cells and the Cell Theory
Robert Hooke First person to observe cells from a cork
- After the invention of a microscope
First to observe single-celled organisms
Anton von
Leeuwenhoek
- From pond scum
- First to see blood, bacterial, and yeast
cells
3 major discoveries led to the Cell Theory
Cell Theory
1. All organisms are made of one or more cells
2. The cell is the basic unit of all living things
3. All cells come from existing cells
Cell Size
Most are too small to see w/o a microscope
- A chicken yolk is one big cell
- Have to be small b/c food and waste must pass
through the outer surface
- As cell’s volume increases, surface areas
increases
surface area
surface area -to -volume ratio =
volume
Parts of a Cell
Cell Membrane - Protective Layer
- Surrounds the cell
-Acts as a barrier
Cytoplasm
Organelles
-controls materials going into and out of cell
- Fluid inside the cell
- Structures within the cell
- Each perform specific functions
Genetic
Material
- DNA (deoxyribonucleic acid)
- Carries information to make new cells
- Contains the code for making proteins
Nucleus
- Holds the DNA
- NOT found in every cell (ex. Bacterial
cells)
2 Types of Cells
Prokaryotic
- Cell without a nucleus
Eukaryotic
- Cell with a nucleus
Prokaryotes
- Single-Celled organisms
- NO nucleus
- NO membrane-bound organelles
2 Types of
Prokaryotes
1. Bacteria
2. Archae
Bacteria
- Smallest cells
- No membrane-bound organelles
- Do contain ribosomes
- Live in water, soil, and on or in other organisms
Flagellum
- Whip-like extension used for movement
Archae
3 Types:
1. Heat-loving
2. Salt-loving
3. Methane-loving
Extremophiles - Archae that live in extreme environments
Eukaryotes
- Organism with one or more eukaryotic cells
- Contain a nucleus(holds DNA)
- Contain membrane-bound organelles
- 10x the size of bacteria cells
- Usually multicellular-many cells
Ex: Humans, Plants, Algae
Multicellular
- Made of many cells
Eukaryotic Cells
Chapter 3: Section 2
Cell Wall
- Not in all eukaryotic cells
- Provides structure and support
Cellulose
- Complex sugar
- Used to make cell wall in plants and algae
- Helps plants and algae retain their shape
Cell Membrane - Found in ALL cells
- Protective barrier
- Outermost layer when cell wall is not present
- Right inside cell wall when present
- Contains proteins, lipids, and phospholipids
- Allows nutrients in and wastes out
Phospholipid
- A lipid containing phosphorus
- Can be hydrophilic or hydrophobic
Hydrophilic
- “Water loving”
- Inner layer of double layered membrane
Hydrophobic
- “Water fearing”
- Outer layer of doubled layered membrane
Cytoskeleton
- Web of proteins
- Contained in cytoplasm
- Acts as muscle and skeleton
- Keeps cell from collapsing
- Can help with movement
- Made of 3 types of proteins: hollow, long, or
stringy
Nucleus
- Contains the cells DNA
- Enclosed by a double membrane
- Contains messages on how to make proteins
- Contains pores to allow material in and out
Ribosomes
- Make proteins (all cells need protein to live)
- Made from amino acids
- Not covered by a membrane
- Found in ALL cells
-smallest of all organelles
Endoplasmic
Reticulum
- Folded membranes
- Where proteins, lipids, and other materials are
made
- A part of the internal delivery system
- Can be rough or smooth
- Rough ER contains ribosomes
- Smooth ER lacks ribosomes
FUNCTIONS OF ER:
-Rough ER is found near nucleus
-Ribosomes in rough ER makes the proteins and then
delivers them throughout the cell
-Smooth ER’s function is making lipids and breaking
down toxic materials that could damage the cell.
Mitochondria
- Main power source of the cell
- Where sugar is broken down to ATP (energy)
- Contains a double membrane
Chloroplasts
- Found in plants and algae
- Site where photosynthesis occurs
-Contains a double membrane(inner/outer)
Photosynthesis - Process plants/algae use sunlight, Carbon
Dioxide, and water to make sugar and oxygen
Golgi Complex - Packages and distributes proteins
- Also modifies lipids and proteins for different
jobs
- Final products remain in a portion of the Golgi
Complex membrane in a small bubble
Vesicle
- A small sac/bubble surrounding materials to be
moved in, out, or within a cell
- Includes products from the Golgi Complex
Lysosomes
Vacuole
- Found in all eukaryotic cells
- Contain digestive enzymes
-Found mainly in animal cells
- Responsible for cellular digestion
- Destroy worn-out cells and cellular waste
- Protects cell from foreign invaders
- A form of a vesicle
- Found in plant and fungus cells
- The central vacuole in plants stores water and
other liquids, helps support the cell
The Organization of Living Things
Chapter 3: Section 3
Benefits of Being Multicellular
1. Larger Size
2. Longer Life
3. Cell Specialization
Cells Working Together
Tissue
- A group of cells that work together to perform a
specific function
- 4 basic types in animals
1. Nerve tissue
2. Muscle tissue
3. Connective tissue
4. Protective tissue
- 3 basic types in plants
1. Transport tissue-moves water/food
2. Protective tissue-covers plant
3. Ground tissue-photosynthesis occurs
Organ
- Two or more tissues working together to
perform a specific function
Ex: Heart, Lungs, Leaf, Roots
Organ System - A group of organs working together to perform
a specific function
Ex: Root System, Digestive System
Organism
- Can perform life processes by itself
Unicellular
An organism made of one cell
- Single cell must be able to perform all life
functions
Multicellular
An organism made of many cells
- Specialized cells that depend on each other
Structure
Arrangement of parts in an organism
Function
The job the part does
- Structure and function are closely related
Ex: Alveoli and Blood Vessels