2. Life is Cellular Cell Structures & Functions Biology I

3. Introduction to Cells Before the 17th century, no one knew cells existed Most cells are too small to be seen with the unaided eye In the early 17th century microscopes were invented & cells were seen for the 1st time Anton Von Leeuwenhoek, a Dutchman, made the first hand- held microscope & viewed microscopic organisms in water & bacteria from his teeth In 1665, an English scientist named Robert Hooke made an improved microscope and viewed thin slices of cork viewing plant cell walls Hooke named what he saw "cells“

4.  The combined work of scientists Schleiden, Schwann, & Virchow is known as the Cell Theory : Principles of the Cell Theory All living things are made of one or more cells Cells are the basic unit of structure & function in organisms Cells come only from the reproduction of existing cells The Cell Theory

5. Cell Diversity Not all cells are alike Cells differ in size, shape, and function The female egg cell is the largest cell in the body & can be seen without a microscope Bacterial cells are some of the smallest cells & are only visible with a microscope

6. Cells come in a variety of shapes, & the shape helps determine the function of the cell (e.g. Nerve cells are long to transmit messages in the body, while red blood cells are disk shaped to move through blood vessels)

7. Basic Structure of a Cell

8. Introduction to Cells  Cells are the basic units of organisms  All cells have a cell membrane and cytoplasm  Basic types of cells: Animal CellPlant Cell Bacterial Cell

9. Number of Cells Organisms may be: Unicellular – composed of one cell Multicellular- composed of many cells

10.  Prokaryotes include bacteria & have NO nucleus or membrane- bound organelles  Eukaryotes include most other cells & DO have a nucleus and membrane-bound organelles Cells Are Divided Into Two Categories

11. Prokaryotic Cells Kingdoms: 1.Monera (Eubacteria) 2.Archaea (Archaebacteria) Characteristics: 1.are usually simpler and smaller than eukaryotes 2. have NO nucleus or membrane-bound organelles 3. Contains a cell membrane and a cytoplasm

12. Prokaryotes Nucleoid region contains the DNA DNA is circular (plasmid) Have a cell membrane & cell wall Contain ribosomes to make proteins in their cytoplasm

13. Prokaryotic Cell - Bacteria

14. Eukaryotic Cells Kingdoms: 1.Protista 2.Fungi 3.Plantae 4.Animalia Characteristics: 1.have a nuclear membrane 2.have membrane-bound organelles

15. Eukaryotic Cell Contain 3 basic cell structures: Nucleus Cell Membrane Cytoplasm with organelles

16. Eukaryotic - Animal Cell

17. Eukaryotic - Plant Cell

18. Two Main Types of Eukaryotic Cells Plant Cell Animal Cell

21. Cell Membrane The boundary of every cell Is said to be selectively permeable because it controls what enters and leaves the cell. Made of protein and phospholipids Other Names: –Phospholipid bilayer –Plasma membrane –Selectively permeable membrane Hydrophobic region Hydrophilic region

23. Cell Wall main function=provide support, shape, & protection for the cell located outside cell membrane found in plants and algae & nearly all eukaryotes (not animal cells) In plants the cell wall is composed of cellulose In fungi the cell wall contains chitin In bacteria it contains peptidoglycan

24. Cytoplasm Jelly-like substance that holds organelles in place. Entire region between the nuclear membrane and the cell (plasma) membrane. cytoplasm Cytoplasm

25. Nucleus Only found in eukaryotes. Contains the genes (DNA - chromosomes) Called the “brain” of the cell because it controls all cell activities. nucleus

26. Large membrane-closed sac for cellular storage. Contains water, sugars, proteins, and nutrients. Called the “central vacuole” in plant cells because it is much larger.Vacuoles Vacuole

27. Organelles Found in Cells  Nucleolus – makes ribosomes  Lysosomes – digests & gets rid of wastes; filled with digestive enzymes  Golgi Apparatus– packages & ships proteins ( Modifies, stores and transports products from the ER to the plasma membrane)  Ribosomes- site of protein synthesis

28. Smooth & Rough Endoplasmic Reticulum Smooth ER lacks ribosomes & makes proteins used in the cell Rough ER has ribosomes on its surface & transports ribosomes

29. Mitochondria Found in both plants and animal cells. It is the site of cellular respiration, a process that uses energy extracted from organic macromolecules (like glucose) to produce ATP (energy). Also known as the “powerhouse” Has a double membrane. Has its own DNA. Outer membrane Inner membrane

30. Chloroplast Outer Membrane Inner Membrane Stroma Granum Thylakoid Found in photosynthetic plants cells. The site of photosynthesis, a process that uses light energy (sun) and water to produce organic macromolecules (glucose).

31. Cytoskeleton network of protein filaments that help the cell to maintain its shape, also involved in cell movement Aids in cellular support and movement Composed of two different components –microtubules-hollow tubes of protein, can serve as “tracks” along which organelles move –microfilaments-long, thin fibers that function in the movement & support of cells

32. Cilia, Flagella, and Pseudopodia Extensions of the cell (plasma) membrane. Aids in movement…. Cilia = hair-like structures all around the cell Flagella = long hair-like structure from the tail region Pseudopodia = “splat” like structure

33. Different kinds of animal cells white blood cell red blood cell cheek cells sperm nerve cell muscle cell Amoeba Paramecium

34. Differences between plant cells and animal cells Animal cellsPlant cells Relatively smaller in size Irregular shape No cell wall Relatively larger in size Regular shape Cell wall present

35. Animal cellsPlant cells Vacuole small or absent Glycogen as food storage Nucleus at the center Large central vacuole Starch as food storage Nucleus near cell wall Differences between Plant Cells and Animal Cells

36. Levels of organization Cells are grouped together and work as a whole to perform special functions

37. Levels of Organization  CELLS (muscle cells,nerve cells)  TISSUES (muscle, epithelium)  ORGANS (heart, lungs, stomach)  SYSTEMS (circulatory system)  ORGANISM (human) It’s You!

38. The cell membrane is a structure that forms the outer boundary of the cell and allows only certain materials to move into and out of the cell. Food, oxygen and water move into the cell through the membrane. Waste products also leave through the membrane.

39. The Endoplasmic Reticulum (ER) is a folded membrane that moves materials around in the cell. The ER is like a system of conveyor belts in a business. They act as tunnels in which materials move from one place to another within the cell.

40. In a business, products are made, packaged, and moved to loading docks to be carried away. In cells, structures called Golgi Bodies are stacks of membrane-covered sacs that package and move proteins to the outside of the cell. Golgi bodies are the packaging and secreting organelles of the cell. Just like a taxi transports people, vesicles transport protein packages created by the golgi bodies. golgi bodies

41. An active cell constantly produces waste products. In the cytoplasm, organelles called lysosomes contain chemicals (enzymes) that digest wastes and worn-out cell parts. These chemicals also break down food. A Lysosome acts as a wrecking ball that breaks apart wastes or worn out cell parts.

42. The largest organelle in the cytoplasm of a eukaryotic cell is usually the nucleus, a structure that directs all the activities of the cell. The nucleus is like a manager who directs everyday business for a company and passes on information to new cells. The nucleus contains genetic blueprints for the operations of the cell.

43. Cells require a continuous supply of energy. Mitochondria are organelles where food molecules are broken down and energy is released. The energy is then stored in other molecules that can power cell reactions easily. Just as a power plant supplies energy to a business, mitochondria release energy for the cell.

44. Cytoplasm is the gel- like material inside the cell membrane and outside the nucleus. Cytoplasm contains a large amount of water and many chemicals and structures that carry out the life processes in the cell. These structures that the cytoplasm contains are called organelles

45. One chemical that takes part in nearly every cell activity is protein. Proteins are needed for chemical reactions that take place in the cytoplasm. Cells make their own proteins on small structures in the cytoplasm called ribosomes. Ribosomes are either free floating in the cytoplasm of a cell or attached to Endoplasmic Reticulum in a cell.Endoplasmic Reticulum Popeye is active because he eats spinach. However, for Popeye's cells to be active, his ribosomes help create proteins

46. Remember the last vacation you took? Your suitcase temporarily stored your clothes. Within a cell, a vacuole fills a similar role as a temporary storage space for the cell. Vacuoles store water, food, pigments, waste or other materials. Vacuoles are large in plant cells and small in animal cells.

47. EukaryotesProkaryotes Bell Ringer… Complete the following Venn Diagrams

48. Plant CellsAnimal Cells