1. The Building Blocks of Life
Cells

2. The Cell Some cells are single organisms
Some cells group together to form living tissues of a larger, more complex organism
A cell is defined as the basic structural and functional unit of all organisms.
It is the smallest living building block of all organisms

3. Robert Hooke The first person to name the cell
was Robert Hooke in 1665
He used an early version of a microscope to look at cork and described the little boxes as cells (as in a jail cell)
He believed only plants had “cells”
From:

4. Van Leeuwenhook
A Dutch inventor who created the microscope that we recognize today
In 1678, he was the first person to discover a single celled protozoa
He called these “Little Animals”
He also looked at blood cells

5. Cell Theory All organisms are made of one or more cells
The cell is the basic unit of all living things
All cells come from existing cells
From :
Cell theory refers to the idea that cells are the basic unit of structure in every living thing. Development of this theory during the Mid 1600s was made possible by advances in microscopy. This theory is one of the foundations of biology. The theory says that new cells are formed from other existing cells and the cell is a fundamental unit of structure, function and organization in all living organisms.

6. Types of Cells Prokaryotes Eukaryotes Think Pro Think “Eu” = You Means
NO!
No nucleus
Think “Eu” = You
You have eukaryotic cells
just like all animals and most
plants.

7. Prokaryotes
Think
Pro
Means
NO!
No nucleus

8. Prokaryote Cell Cells that DO NOT have a nucleus.
These single cells are molecules surrounded by a membrane and cell wall.
Prokaryotic cells lack typical
“organelles”, but may contain
a membrane system inside a
cell wall.
Examples include simple
bacteria

9. Eukaryotes Think “Eu” =You You have eukaryotic cells
just like all animals and most
plants.

10. Eukaryotes
Eukaryotic Cell Cells that have a nucleus and usually have organelles that perform specific jobs for the cell.
Example – Plant and Animal Cells are Eukaryotic
Eukaryotic cells usually are 10
times larger
than Prokaryote cells.
See the visible nucleus (dark spot)

11. Typical Eukaryotic Cell

12. Difference between cell types

13. Eukaryotes have organelles
Organelles are the structures (PARTS) inside of a cell that perform the functions necessary for the cell to survive.
Example: Think about your heart, lungs and liver… They are all organs inside of your body. The cell has parts like this inside of its cell that are called
organelles.

14. Organelles have specific jobs

15. Cell Membrane
The cell membrane is the protective layer that covers the cell’s surface.
It acts like the fence around a yard. It is like the skin on your body. It keeps some things out and lets other things in.

16. Functions of the cell membrane
Support
Protection
Controls movement of materials in/out of cell
Barrier between cell and its environment
Maintains homeostasis

17. Cell Wall Cell Wall: not found in animal cells
Gives support to the cell
Is a second layer or “fence” like the cell membrane.

18. Found in : plant, fungi, and some bacteria, but not animal cells
not found in animal cells
Found in : plant, fungi, and some bacteria, but not animal cells
Description :
Outer layer that is rigid & strong
Made of cellulose
Function –Support and protection of cell

19. Nucleus
Nucleus: An organelle inside of the cell that directs the activity in the cell.
It holds the DNA (chromosomes)
This is the blue print material (directions) for the cell.
It tells how to reproduce and perform all of the cells jobs.
nucleus

20. The Nucleus is like your brain!
The nucleus tells all the other cell parts what to do.

21. Mitochondria
Mitochondria The organelle that releases energy in the cell. (The powerhouse of the cell)
Breaks down sugar (glucose) molecules to release energy

22. Chloroplasts (plants only)
Chloroplasts Organelle that produces chlorophyll. ( The chemical of photosynthesis) to power the plant cell.
Chlorophyll traps the energy of sunlight, which is then used by the plant cell to make sugar for energy.
Only found in PLANT cells.

23. Function of the chloroplasts
Uses energy from sun to make food (glucose) for the plant
Process called photosynthesis
Responsible for the
conversion of
Carbon dioxide to
Carbohydrates
Similar to the
mitochondria of the animal cells

24. Cytoplasm Cytoplasm The gel-like material inside of the cell membrane.
Found in all cells
Keeps organelles in place

25. Cell Movement
Some single celled organisms must move about to search for food.
They can move by:
Cilia
Flagella (whip-like tails)
Pseudopods (false feet) 1 2 3

26. Movement Examples
Pseudopod
movement

27. Cells and your body
The cells in your body function similar to the way your entire body works
The nucleus (brain) tells the cell what to do
The organelles each perform a specific task to help the body survive
All living things are made up of cells.

28. Responsible for intracellular digestion and the release of cellular waste products.
In animal cells, vacuoles are generally small.
Large in plant cells and play a role in turgor pressure.

29. Ribosomes Lysosomes Endoplasmic Reticulum
Site of protein synthesis, it may be free in the cytoplasm or attached to membranes.
Lysosomes
Contains digestive enzymes, if it breaks it will kill the cell
Endoplasmic Reticulum
Interconnection channels that store and transport materials around the cell.

30. Questions for Thought
Why are cells considered the most basic level of life?
Why are Eukaryotes considered more advanced than Prokaryotes?
Name some cells in your body. Are they all alike or different?
How would our bodies work differently if we had chloroplasts in our body cells?

31. Aliens Aliens are often shown as being green creatures?
Can you guess why?

32. Answer
Many scientists believe if there is life on other planets that it would have evolved differently than life on Earth. One belief is that life forms would be a cross between animals and plants and, therefore, aliens would have the ability to use sunlight as a source of food. Cool!

33. References