1. Cells
The Basic Units of Life

2. Living things are different from nonliving things…
You are surrounded by life, but how would you define a living thing?
DDoes it use energy?
DDoes it move?
DDoes it consume food and water?
Organism- any individual form of life that uses energy to carry out its activities.

3. Characteristics of Living Things
All living things:
D are made up of cells (organization).
D respond to the environment. D have the ability to reproduce. D move.
D grow and develop.
D perform metabolic processes.
Metabolism- the sum of the physical and chemical processes in an organism

4. What about Viruses?
Have genetic material (DNA or RNA) surrounded by a protein coat
Can replicate (with host)…BUT only with a host
Have a protein coat

7. What is a Cell? Cell – Basic unit of living things.
Organisms are either:
Unicellular – made of one
cell such as bacteria and
amoebas. OR
Multicellular – made of
many cells such as plants
and animals.

8. Why Cells are Important
What happens inside cells causes us to be who we are. (Genes)
All diseases start at the level of the cell.
All growth and life starts from a single cell.

9. The microscope led to the discovery of cells.
1660’s – Robert Hooke discovered the cell
D He looked at cork under the microscope (30x)
D He noticed little compartments, which he named after the little rooms that monks lived in…”Cells”
1670’s – Anton von Leeuwenhoek described microorganisms in pond water
D He looked at pond water under the microscope (300x)
D He noticed that the water was full of moving living things

10. Cell Theory
Confirmed discoveries that all scientists believe to be true about cells:
1. Cells are the basic unit of life.
2. All living things are made of cells.
3. New cells are produced from existing cells.

11. Types of Cells
Prokaryotic
before
nucleus
Eukaryotic
true
nucleus

12. Prokaryotes Simplest, “primitive” cells with:
NO membrane-bound organelles (just ribosomes)
NO nucleus: genetic material floats free in cell surrounded by the plasma/cell membrane

13. Prokaryotes ALL are unicellular Smaller than eukaryotic cells
DNA – single strand and circular
Ex: ALL Bacteria 13

14. Bacteria (Kingdom Monera)
Two Subdivisions:
1. Eubacteria – “true bacteria”
2. Archaea – “ancient bacteria”
Extremophiles: live in harsh environments (hot, acidic, salty)
Youbacteria
Arch keya
Extemofiles 14

15. Unicellular or multicellular Cells contain:
a nucleus (with DNA)
membrane-bound organelles
Complex internal structure
“Compartments” allow many different chemical reactions to take place simultaneously

16. Eukaryotes Has a nucleus with a nuclear envelope
DNA – double-stranded and forms chromosomes (highly organized)
Ex: animals, plants, fungi

17. Examples: Kingdom Protista – protozoa, algae, amoeba
Kingdom Fungi – mushrooms, molds, yeast

18. -Kingdom Plantae (Plants)– ranges from moss to flowering plants
-Kingdom Animalia (Animals) – ranges from tiny worms to humans

19. Viruses are extremely small!

20. How They Differ Prokaryotes Organelles lack a cell membrane
Ribosomes are the only organelles
Genetic material floats in the cytoplasm (DNA and RNA)
Eukaryotes
Organelles covered by a cell membrane
Multiple organelles including ribosomes
Membrane covered Genetic material

21. Prokaryotes
Circular DNA
Unicellular
Cells are smaller in size
Has larger number of organisms
Appeared 4 billion years ag
Eukaryotes
Linear DNA
May be multicellular or unicellular
Cells are larger in size
Has smaller number of organisms
Appeared 1 billion years ago

22. Similarities Contain all four biomolecules Have ribosomes Have DNA
(lipids, carbs, proteins, and nucleic acids)
Have ribosomes
Have DNA
Similar Metabolism
Can be unicellular
Have cell/plasma membranes or cell wall

23. Eukaryote VS. Prokaryote Picture

24. Cell Organelles
Eukaryotic Cells

25. Cell Organelles
Organelles are responsible for working together to make up the cell, while the cell is responsible for making up the tissue which are responsible for making up the organ which is responsible for making up the organ system.

26. Cell Parts Cells – the basic unit of life
Organelles - small structures inside a cell with specific functions.

27. Cell Membrane/Plasma Membrane
Function: Regulates materials entering and exiting the cell.
Structure: Two layers of phospholipids, proteins

28. Cytoplasm
Cytoplasm
Function: All cell contents that lie between the cell membrane and the nucleus. (organelles + cytosol)
a. Cytosol = liquid portion/non-organelles.
Structure: made up of fluid and organelles except for nucleus

29. Nucleus Function: “Control Center.” Regulates DNA & RNA actions.
Structure: membrane bound, contains DNA

30. Nuclear Envelope Function: Regulates what enters or exits the nucleus.
Structure: Double Layer of Lipids

31. Nucleolus Function: Produces RNA, which are used to make all proteins.
Structure: Inside Nucleus, separate from DNA

32. DNA – Deoxyribonucleic acid
DNA (chromatin)
Function: information on how to make proteins.
Chromatin – unorganized DNA (normal state)
Chromosomes – organized DNA (present before cell division
Structure: Made up of nucleotides, locked in the nucleus

33. Endoplasmic Reticulum
Rough ER
Smooth ER
Function: Transportation route for proteins.
Rough ER: has ribosomes
Smooth ER: no ribosomes
Structure: tubes and channels

34. Ribosomes Function: Makes proteins.
Free Ribosomes
Function: Makes proteins.
Structure: small circular organelles

35. Vacuoles & Vesicles Function: Storage for water, nutrients or waste.
Structure: small membrane-bound organelle.

36. Lysosomes
Lysosomes
Function: packets of enzymes that break down materials in a cell.
Structure: Small membrane-bound organelles

37. Mitochondria
Mitochondria
Function: Produce energy for the cell – site of cellular respiration. “The Powerhouse”
Structure: Double membrane-bound, kidney shaped.

38. Golgi Apparatus
Golgi Apparatus
Function: Packages, labels and ships proteins out of the cell.
Structure: Pancake-shaped layered organelle

39. Cytoskeleton Function: Provide support and structure for the cell.
Microfilaments
Microtubules
Function: Provide support and structure for the cell.
Microfilaments
Microtubules
Structure: Tubules

40. Centrioles (Animals Only)
Function: microtubules that help divide the cell during cell division.
Structure: Tubules

41. Cilia & Flagella
Cilia
Flagella
Flagella
Function: provides movement for the cell or objects moving by the cell.
Structure:
Flagella – 1 long fiber
Cilia – many short fibers

42. Chloroplasts (Plants only)
Function: site of photosynthesis (converting sun and CO2 into sugar).
Structure: Membrane bound organelles that contain chlorophyll

43. Cell Wall (Plant cells only)
Function: Provides support for the cell and the plant.
Structure: Made of cellulose

44. Cell Organelles
Prokaryotic Cells

45. Prokaryotic cell walls
Surrounds and protects cell and maintains cell shape

46. Nucleoid (Nuclei)
DNA in the bacterial cell is generally confined to this central region. Though it isn't bounded by a membrane, it is visibly seen through a microscope.
Nucleoid

47. Flagella, Pili
Whip-like proteins attached to cell wall used for locomotion
Present in some prokaryotic cells
one to several flagella on a single cell
Rotary motion of flagellum propels the cell through fluid environment
Flagella powered by protein motors
uses energy of a proton gradient

48. Flagella Structure