Review Facts About Living Things

1. Review Facts About Living Things

2. What Are the Main Characteristics of organisms? • Made of CELLS • Require ENERGY (food) • REPRODUCE (species) • Maintain HOMEOSTASIS • ORGANIZED • RESPOND to environment • GROW and DEVELOP • EXCHANGE materials with surroundings (water, wastes, gases)

3. LEVELS OF ORGANIZATION Nonliving Levels: • ATOM (element) • MOLECULE (compounds like carbohydrates & proteins) • ORGANELLES (nucleus, ER, Golgi …)

4. LEVELS OF ORGANIZATION Living Levels: • CELL (makes up ALL organisms) • TISSUE (cells working together • ORGAN (heart, brain, stomach …) • ORGAN SYSTEMS (respiratory, circulatory …) • ORGANISM

5. LEVELS OF ORGANIZATION Living Levels continued: • POPULATION (one species in an area) • COMMUNITY (several populations in an area • ECOSYSTEM (forest, prairie …) • BIOME (Tundra, Tropical Rain forest…) • BIOSPHERE (all living and nonliving things on Earth)

6. History of Cells & the Cell Theory Cell Specialization

7. First to View Cells • Before we could begin to investigate cells, the technology that allowed for the viewing of the smallest unit of life needed to be developed: THE MICROSCOPE • In 1665, Robert Hooke used a microscope to examine a thin slice of cork (once were PLANT cell walls) • What he saw looked like small boxes

8. First to View Cells • Hooke is responsible for naming cells • Hooke called them “CELLS” because they looked like the small rooms that monks lived in called Cells

9. Anton van Leeuwenhoek • In 1673, Leeuwenhoek (a Dutch microscope maker), was first to view organism (living things) • Leeuwenhoek used a simple, handheld microscope to view pond water & scrapings from his teeth

10. Cell Theory In 1838, a German botanist named Matthias Schleiden concluded that all plants were made of cells • Schleiden is a cofounder of the cell theory

11. Cell Theory • In 1839, a German zoologist named Theodore Schwann concluded that all animals were made of cells • Schwann also cofounded the cell theory

12. Cell Theory • In 1855, a German medical doctor named Rudolph Virchow observed, under the microscope, cells dividing • He reasoned that all cells come from other pre-existing cells by cell division

13. CELL THEORY 1. All living things are made of cells (Schwann and Schleiden) 2. Cells are the basic unit of structure and function in an organism (basic unit of life) cells – tissue – organs – system. 3. Cells come from the reproduction of existing cells (cell division) (Virchow)

14. Simple or Complex Cells

15. Prokaryotes – The first Cells • Prokaryotic Cells (from the greek word “before nuclei” • Only Bacteria are prokaryotic • (Archaea and Eubacteria Kingdoms) • Prokaryotes lack a nucleus or any other membrane bound organelles but they do have genetic material (DNA) • Size is smaller

16. Prokaryotes • Nucleoid region (center) contains the DNA • Surrounded by cell membrane & cell wall(peptidoglycan) • Contain ribosomes (no membrane)in their cytoplasm to make proteins • All Prokaryotic cells have a cell wall

17. Eukaryotes Animal, Plant, Fungi and Protist kingdom • Cells that HAVE a nucleus and membrane-bound organelles • Larger then Prokaryotic

18. BACTERIA are ProkaryoticThey don’t have a nucleus or other membrane bound organelles

19. Cell wall – gram positive cell wall – are bacteria that have cell walls that are thick and easy to treat with antibiotics. Gram negative cell wall – are bacteria that have cell walls that are much thinner and are harder to treat. Capsule – not all bacteria have a capsule. The function of the capsule on bacteria is extra protection. Ribosomes – performing protein synthesis; smaller than eukaryotic ribosomes Flagellum – allows for movement (not made of microtubules). A cell may have multiple flagella arranged around it.

20. Nuclear Material – A folded mass of DNA, containing all the genes required for vital functions. Plasmid – the circular structure in the Bacteria. It is an additional piece of circular DNA that a bacteria passes on during sexual reproduction. Pili – hair-like projections that helps the bacteria to “stick” to surfaces.

21. ENDOSYMBIOTIC THEORY • In 1970, American biologist, Lynn Margulis, provided evidence that some organelles within cells were at one time free living cells themselves • 1. Small, aerobic prokaryotic cells were engulfed by larger prokaryotes (a process called ENDOCYTOSIS – “inside the cell”) • 2. Rather than digesting the smaller cell, the 2 cells formed a symbiotic (mutual) relationship. The host cell helped provide nutrients and the internal cell helped to produce energy. • 3. Eventually ,the 2 cells become dependent (reliant on one another to survive.

22. Supporting evidence included organelles with their own DNA • Chloroplast and Mitochondria The oxygen producing bacteria became the mitochondria Some of the prokaryotic cells engulfed were blue-green algal cells – which became the chloroplast

23. Evidence --- both mitochondria and chloroplast have their own DNA and have 2 membranes.

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

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

27. Organelles

28. Organelles • Very small (Microscopic) • Perform various functions for a cell • Found in the cytoplasm • May or may not be membrane-bound

29. Animal Cell Organelles Ribosome (attached) Nucleolus Ribosome (free) Nucleus Cell Membrane Nuclear envelope Mitochondrion Smooth endoplasmic reticulum Rough endoplasmic reticulum Centrioles Golgi apparatus

30. Plant Cell Organelles

31. Basic Structure of a Cell

32. Outside of cell Carbohydrate chains Proteins Cell membrane Inside of cell (cytoplasm) Protein channel Lipid bilayer Cell or Plasma Membrane • Composed of double layer of phospholipids and proteins • Surrounds outside of ALL cells • Controls what enters or leaves the cell • Living layer

33. Phospholipids • Heads contain glycerol & phosphate and are hydrophilic (attract water) • Tails are made of fatty acids and are hydrophobic (repel water) • Make up a bilayer where tails point inward toward each other • Can move laterally to allow small molecules (O2, CO2, & H2O to enter)

34. The Cell Membrane is Fluid Molecules in cell membranes are constantly moving and changing

35. Proteins help move large molecules or aid in cell recognition Peripheral proteins are attached on the surface (inner or outer) Integral proteins are embedded completely through the membrane Cell Membrane Proteins

36. GLYCOPROTEINS Recognize “self” Glycoproteins have carbohydrate tails to act as markers for cell recognition

37. Cell Membrane in Plants Cell membrane • Lies immediately against the cell wall in plant cells • Pushes out against the cell wall to maintain cell shape

38. Cytoplasm of a Cell cytoplasm • Jelly-like substance enclosedby cell membrane • Provides a medium for chemical reactions to take place

39. More on Cytoplasm cytoplasm • Contains organelles to carry out specific jobs • Found in ALL cells

40. Ribosomes • Made of PROTEINS and rRNA • “Protein factories” for cell • Join amino acids to make proteins • Process called protein synthesis 

41. Ribosomes Can be attached to Rough ER OR Be free (unattached) in the cytoplasm

42. The Control Organelle - Nucleus • Controls the normal activities of the cell • Contains the DNA in chromosomes • Bounded by a nuclear envelope (membrane) with pores • Usually the largest organelle

43. More on the Nucleus Nucleus • Each cell has fixed number of chromosomes that carry genes • Genes control cell characteristics

44. Nucleolus • Inside nucleus • Cell may have 1 to 3 nucleoli • Disappears when cell divides • Makes ribosomes that make proteins

45. Inside the Nucleus - The genetic material (DNA) is found DNA is condensed & wrapped around proteins forming as CHROMOSOMES in dividing cells DNA is spread out And appears as CHROMATINin non-dividing cells

46. What Does DNA do? DNA is the hereditary material of the cell Genes that make up the DNA molecule code for different proteins

47. Nuclear Envelope • Double membrane surrounding nucleus • Also called nuclear membrane • Contains nuclear pores for materials to enter & leave nucleus • Connected to the rough ER Nuclear pores

48. Mitochondrion(plural = mitochondria) • “Powerhouse” of the cell • Generate cellular energy (ATP) • More active cells like muscle cells have MORE mitochondria • Both plants & animal cells have mitochondria • Site of CELLULAR RESPIRATION (burning glucose)

49. MITOCHONDRIA Surrounded by a DOUBLE membrane Has its own DNA Folded inner membrane called CRISTAE (increases surface areafor more chemical Reactions) Interior called MATRIX

50. Interesting Fact --- • Mitochondria Come from cytoplasm in the EGG cell during fertilization Therefore … • You inherit your mitochondria from your mother!