1. Cells - Structure and Function of Organelles

2. Eukaryotic vs. Prokaryotic Prokaryotic organisms are single-celled bacteria that evolved early and are very simple. They do not have nuclei! Eukaryotic organisms evolved later and are more complex. The cells of eukaryotic organisms contain nuclei.

3. Prokaryotic cell = simple cell; no nucleus; evolved first Example = Bacterial cell

4. Eukaryotic cell = more complex; evolved later; contains a nucleus (and many other organelles) Example = corn cell

5. Plasma Membrane (“Cell Membrane”) Phospholipid bi-layer Hydrophilic heads (love water) Hydrophobic tails (hate water) Made up of phospholipids with embedded proteins and carbohydrates to provide functionality Function = Protect cell from surrounding environment and regulate what enters and leaves a cell (“traffic cop”) Selectively permeable Found in ALL cells

6. This picture shows the plasma membranes of 2 cells lined up next to each other.

7. Plasma membrane - cross section Looking down on a plasma membrane

10. Cell Wall Functions to support and protect the cell Only found in plant cells Made of the carbohydrate cellulose - a tough carbohydrate Very permeable (stuff still needs to get in and out of the cell!) Found outside the plasma membrane

14. Organelle A structure with a specialized function found within the cell

15. Nucleus Contains the genetic material of the cell (DNA) “Control center” (brain) of the cell Surrounded by a double membrane (the nuclear envelope) that has large pores Found in plant and animal cells but not in bacteria cells (bacteria are prokaryotes)

16. nucleus

20. Nuclear Envelope Double membrane that surrounds the nucleus Porous (has pores) and very permeable Allows most substances to enter or leave the nucleus

23. Nucleolus Dark staining area of the nucleus where ribosomes are made (“ribosome factory”) There can be more than 1 in a cell (usually 1-3)

25. Chromosomes Tightly packed chromatin (DNA and proteins) found in the nucleus Visible only when the cell is dividing Human Chromosomes

27. Chromatin Thin strands of DNA and protein that condense to form chromosomes

28. chromatin fragments from chicken

29. Cytoplasm The watery region of a cell between the plasma membrane and the nucleus (does not include the nucleus) Watery solution of dissolved salts, sugars, amino acids, proteins, etc… In both plant and animal cells

32. Ribosomes Function in the synthesis of proteins (“protein factories”) Tiny and numerous organelles Ribosomes are usually attached to endoplasmic reticulum but can also be free within the cell Found in both plant and animal cells

33. Popeye is active because he eats spinach. However, for Popeye's cells to be active, his ribosomes help create proteins.

35. Rough Endoplasmic Reticulum “Intracellular highway” - the path in the cell along which molecules (proteins) travel Called “rough” because it’s covered with ribosomes Found in both plant and animal cells

37. Smooth Endoplasmic Reticulum Smooth because it is not covered with ribosomes One main function is to breakdown toxic substances within the cell “HAZ-MAT team” In both plant and animal cells

41. Golgi Apparatus “Protein packaging factory” A system of membranes that prepares proteins for export out of the cell In both plant and animal cells

45. Lysosomes Function in digesting old materials in the cell (“recycling center”) Contain enzymes that do the work of breaking down large molecules Single membrane Found in animal cells, fungi, and bacteria, but rare in plant cells

49. Vacuoles (animal) Protists have contractile vacuoles that function to expel excess water out of the cell

51. Vacuoles (plant cell) Large, fluid-filled sac that stores water and dissolved solutes (such as enzymes and metabolic wastes) Function in structure and support of plant cells (regulates turgor pressure within the cell)

53. Mitochondrion (mitochondria = plural) Where cellular respiration occurs ATP (cellular enery) is made out of organic compounds Double membrane –Outer membrane protects mitochondrion –Inner membrane has many folds known as cristae - these folds greatly increase the surface area of the membrane Contain its own DNA! In both plant and animal cells

57. Chloroplast Function in converting the energy of sunlight into chemical energy (photosynthesis) “Food factory of plants” Contain disks (known as thylakoids) in stacks (known as grana) Contains a green pigment (chlorophyll) Only in plants

60. Chlorophyll The green pigment found in plant chloroplasts Used in photosynthesis to trap sunlight energy.