1. Cell Structure & Function Ch.4 & 1-4

2. (4-1) History Cell: smallest unit that can carry on the processes of life Hooke (1665): looked at plants under microscope & saw “little boxes” –Named them “cells” Leeuwenhoek (1673): 1 st to see living cells

3. Cell Theory 1. All living things are composed of cells 2. Cells are the basic unit of an organism 3. Cells only come from the reproduction of existing cells

4. (4-2) Intro to Cells Cell Diversity –Your body has over 200 different types of cells Red Blood Cells Bacterial CellsSkin Cells

6. Cell Size Most cells are microscopic Limited by surface area to volume ratio –Larger ratio = more efficient

8. Surface Area to Volume Ratio Surface Area: L x W x # of sides Volume: L x W x H Ratio: SA / V

12. Cell Shape Determined by the function of the cell

13. Basic Parts of a Cell Plasma (cell) membrane: covers cell’s surface & provides barrier Cytoplasm: fluid (cytosol), cytoskeleton, & organelles inside membrane –Site of chemical rxns Nucleus: control center

16. Basic Cell Types “Before nucleus” (nucleoid) No membrane organelles Single cell organisms “True nucleus” Membrane organelles Multicellular & single cell organisms Prokaryotic vs. Eukaryotic

17. Cellular Organization Colonies: –Identical cells in a connected group –Not multicellular (few activities coordinated) Multicellularity: –Tissue –Organ –Organ system

18. (4-3) Organelles & Features Structures are determined by the functions of each part

19. Plasma Membrane Function: allows substances into & out of the cell Selectively permeable: allows only certain things to cross the membrane

20. Parts of the Membrane Membrane lipids –Phospholipid bilayer: hydrophobic & hydrophilic ends

21. Parts of the Membrane (cont.) Membrane proteins –Peripheral proteins: attached to sides –Integral proteins: embedded w/in

22. Fluid Mosaic Model Membrane behaves like a liquid Mosaic: changing pattern of proteins & lipids

23. Nucleus Function: store hereditary info (DNA) & control the cell Contains: –nuclear envelope: surrounds nucleus –nuclear pores: holes in envelope that allows material to enter & leave nucleus –nucleolus: area of concentrated DNA (chromatin)

24. Mitochondria Function: makes ATP (E) “Powerhouse” of the cell Has own DNA

25. Rough Endoplasmic Reticulum (RER) Function: makes proteins & phospholipids, & prepares molecules for export out of cell Attached ribosomes make “rough”

26. Smooth ER (SER) Function: makes lipids & steroid hormones, metabolizes carbs, regulates Ca 2+ levels, & is detoxification center for cell

27. Ribosomes Function: makes proteins

28. Golgi Apparatus Function: stores, sorts, modifies, & ships materials out of the cell

29. Vesicles Lysosomes: break down macromolecules –Release glucose into blood –Break down bacteria Peroxisomes: break down fatty acids –Detoxification center in liver cells

30. Cytoskeleton Function: support system of the cell; aid in movement w/in the cell –Microtubules –Microfilaments

31. Cilia & Flagella Function: locomotion & movement of materials around the cell Animal cells only*

32. (4-4) Plant Cell Organelles Cell Wall Central vacuole Plastids

33. Cell Wall Function: protects the cell; gives shape & structural support Outside cell membrane Made of cellulose & proteins

34. Central Vacuole Function: stores materials such as water, enzymes, & waste Other vacuoles store toxins

35. Plastids Have their own membrane & DNA & store materials (pigments, starch) Chloroplasts: plastids that undergo photosynthesis

36. (1-4) Microscope Instrument that produces an enlarged image of an object Magnification: increase of an object’s size Resolution: ability to show details clearly

37. Light Microscopes Stage: where slide is placed Objective lens: enlarges image Ocular lens: magnifies image further Nosepiece: revolves lenses Power of magnification: factor of enlargement –Obj. x ocular = total power of mag. –Ex: 40X x 10X = 400X

38. Light Microscope (cont.) Diaphragm: adjusts amount of light Coarse-adjustment: focuses specimen Fine-adjustment: focuses specimen even more

40. Electron Microscopes Beam of e- produces enlarged image of nonliving specimen More powerful than light microscopes 2 types: –Transmission (TEM) –Scanning (SEM)