1. Cells

2. All living things are made up of cells….
The cell is the smallest unit of a living thing.
If an organism is unicellular, all functions of life happen within that one cell.
If an organism is multicellular, different cells have different jobs and they all work together.

3. Level 1 : Cells Cells can be specialized (have a certain function)
The size and shape of a cell relates to its job or function.
Cells are made of different structures that perform different functions that keep a cell alive.

4. Cells are small Click link below:

5. Level 2: Tissues
Tissue = group of cells that work together to do a specific job
Ex: Heart muscle tissue is made of heart muscle cells
Animals have 4 types of tissue: nerve, muscle, connective, protective
Plants have 3 types of tissue : transport, protective, ground

6. Level 3: Organs
Organ = structure that is made up of 2 or more tissues working together to get a specific job done
Ex: Stomach – muscle tissue moves food, special tissues make chemicals to digest food, connective tissue holds stomach together, nervous tissue sends messages back and forth between the stomach and brain

7. Level 4: Organ Systems
Organ system = group of organs working together to perform a specific function
Each organ system has a specific job
Ex: Digestive system is made of several organs including the stomach and intestines

8. Levels of Organization
Cells
Tissues
Organs
Organ Systems
Organism
Cells  Tissues  Organs  Organ  Organism
Systems

9. Organism
Anything that can live on its own
Means “organized”
Unicellular
multicellular

10. Unicellular Organisms
“uni-” = one
Prokaryotes are unicellular organisms
Some algae, some protists, and some eukaryotes (yeasts), are unicellular
Can still do everything they need to stay alive

11. Multicellular Organisms
“multi-” = more than one
Plants, animals, some protists, and most fungi are multicellular
Start as a single cell  many cells  cells differentiate (change) into different types of cells  cells group together
Advantages- can grow larger and have specialized cells for different functions
Link:

12. Why do we hear so much about stem cells & what are they?
The human body is composed of many different types of cells
e.g. muscle cells, skin cells, liver cells, cardiovascular cells, etc.
Not all cells have the same potential
Some cells remain “immature”—these are stem cells
When stem cells “mature,” or differentiate they turn into the different cells of the body (or somatic cells)

13. Stem cells are multi-talented
Self-renew
a stem cell can reproduce itself
by cell division
Differentiate
a stem cell can specialize into a particular type of somatic cell

14. There are two main types of Stem Cells—Adult & Embryonic Stem Cells
Adult stem cells
found in adult tissue
can self-renew many times
are multipotent – they can differentiate to become only the types of cells in the tissue they come from.
hematopoietic stem cells – give rise to blood cells
mesenchymal stem cells – give rise to cells of connective tissues and bones
umbilical cord stem cells – a rich source of hematopoietic stem cells
stem cells found in amniotic fluid – might be more flexible than adult stem cells

15. There are two main types of Stem Cells—Adult & Embryonic Stem Cells
come from embryos
This stage embryo is called a Blastocyst
~5 days old, a hollow microscopic ball of cells
can self-renew forever; adult stem cells have a cell-division limit
are pluripotent – they can differentiate to become almost EVERY cell in the body
live in a Petri dish, not a woman's body

16. The Discovery of Cells
In 1665 Robert Hooke looked at cork under the microscope and described what he saw as “tiny rooms” or “cells”

17. Cell theory includes three principles.
Getty Images

18. Concept #3- All polar bears
cell came from a single living
cell. They divide and they
grow to replace old dead cells!
Concept #1- A polar
bear is made up of
many cells!
Concept #2- Different cells in
a polar bears body does
different jobs (functions).
Example: Fat
cells provide insulation and
energy, while red blood cells
carry oxygen.

19. Basic Cell Substances
The main ingredient in any cell is water. A water molecule has two areas:
The negative (–) end can attract the positive part of another substance.
The positive (+) end can attract the negative part of another substance.

20. All cells have: Cell membrane
a flexible covering that protects the inside of a cell from the environment outside a cell.
controls movement of materials in & out of the cell

21. All cells have: 2. Hereditary material- DNA
A nucleic acid, such as DNA, contains the genetic information for a cell.

22. All cells have:
3. Cytoplasm- Clear, thick, gel-like fluid that contains most of the cell’s water, salts, and all organelles
*It is constantly moving
cytoplasm
from Greek kytos, means “hollow vessel”; and plasma, means “something molded”

23. All cells have: 4. Organelles-
tiny membrane-surrounded structures inside the cell that carry out specific functions.
They enable the cell to live, grow, and reproduce

24. Cell Types
With more advanced microscopes, scientists discovered that all cells can be grouped into two types:
prokaryotic cells
eukaryotic cells
Most prokaryotic cells are unicellular organisms called prokaryotes.

25. Prokaryotes: NO NUCLEUS!
1st cells to evolve
Have No Nucleus!
The hereditary information (circular DNA) is contained within the cytoplasm.
Examples: Archaebacteria and Bacteria
*”Pro” rhymes with “No”

26. The genetic material in a prokaryotic cell is not surrounded by a membrane.

27. Eukaryotes Evolved from prokaryotes
Organisms whose cells do have a nucleus.
Hereditary information (Linear DNA) is contained within the nucleus
Examples:
Animals
Plants
Protists
Fungi
*“You” are a Eukaryote.

28. Cell Types (cont.)
Plants, animals, fungi, and protists are all made of eukaryotic cells and are called eukaryotes.
In eukaryotic cells, the genetic material is surrounded by a membrane.

29. Why are cells so small? Cell size is limited.
-As cell size increases, it takes longer for material to diffuse from the cell membrane to the interior of the cell.
Surface area-to-volume ratio: as a cell increases in size, the volume increases 10x faster than the surface area

30. Cell size is limited

31. Cell Organelles

32. Plant Cell
Animal Cell
Can you identify the two organelles that are only found in the plant cell?

33. Cell Membrane • It’s like the border of a city! -Surrounds all cells
– In a plant cell, it lies beneath the cell wall
– In animal cells, it is the outer boundary (made of cholesterol)
– Serves as a gateway which helps to control materials going in and out of the cell

34. Nucleus • Found in both plant and animal cells
• Centrally located in cell
The nucleus acts as the “brain” of the cell, controls all the activities of the cell and contains genetic information stored in DNA.
• It’s like the Mayor’s Office in City Hall!

35. EM Research Services, Newcastle University
Nucleus (cont.)
In most cells, the nucleus is the largest organelle.
EM Research Services, Newcastle University 35

36. Nucleus (cont.)
DNA in the nucleus is organized into structures called chromosomes.
The nucleolus is also contained in the nucleus and makes ribosomes, organelles involved in the production of proteins.
The nuclear envelope is a porous, two-membrane structure that surrounds the nucleus. 36

37. Endoplasmic Reticulum
• Found in both plant and
animal cells
• Network of tubes that transports materials throughout the cell
• Two types
– Smooth (no ribosomes)
– Rough (covered with
ribosomes)
It’s like a city’s subway!

38. Ribosomes • It’s like the brick yard that supplies a city with
• Found in both plant and animal cells
• Can be attached to the ER Membrane or floating free in the cytoplasm
• The smallest organelles
Function: Synthesis- Produce proteins and pass them to the interior of the ER.
• It’s like the brick yard
that supplies a city with
what it’s made of!

39. Mitochondria It’s like a city’s power plant!
• Found in both plant and animal cells
Powerhouse of the cell
• Breaks down sugar molecules to release energy
• Function: Respiration- Releasing energy stored in food
food is “burned” (combined with oxygen) to produce energy for the cell in the form of ATP

40. Vacuoles • Fluid-filled sacs found in both plant and animal cells
– In plant cells: very few and very large
– In animal cells: many little ones
• Store food, water and waste
It’s like a city’s warehouses, water towers and landfills!

41. Cell Wall It’s like the wall that surrounds a medieval city!
Only found surrounding plant, fungal and bacterial cells
A cell wall is a stiff structure outside the cell membrane that protects a cell from attack by viruses and other harmful organisms.
Made of cellulose- a tough, yet flexible material
Provides support, structure, and protection for the cell
It’s like the wall that surrounds a medieval city!

42. Chloroplasts • Found in plant cells only
• Found in plant cells only
• Green in color due to a pigment called chlorophyll
They capture energy from the sun and use it to produce food (sugar) for the cell during photosynthesis
It’s like the solar
panels on a city’s
buildings!

43. City planning office that works with the Mayor’s office
Chromosomes
Found in both plant and animal cells
Coiled structures of DNA & protein; found in the nucleus
City planning office that works with the Mayor’s office

44. Nucleolus Makes Ribosomes Found in both plant and animal cells
It’s like a Factory!

45. Lysosomes Found in both plant and animal cells
Function: contains digestive enzymes that digests old cell parts.
They are the cell’s clean-up crew. They have their own membrane to protect the cell from their chemicals.
It’s like a city’s street sweeper!

46. Golgi Bodies (Complex)
Found in both plant and animal cells
Looks like a flattened stack of membranes (or pancakes!)
They receive proteins from the ER, package them into vesicles, and distribute them out of the cell.
Vesicles are organelles that transport substances from one area of a cell to another area of a cell.
• It’s like a city’s
Post Office!

47. Cytoplasm Found in both plant and animal cells
• Clear, thick, jelly-like material
• Located beneath cell membrane
Surrounds and protects cell organelles
• It’s like the air in a city!

48. Plant Cell Animal Cell

49. Golgi bodies or ER
Mitochondria
ribosomes
chloroplasts
Lysosomes
vacuoles
nucleus
Cell wall or cell membrane

50. THE END