1. Cells Review
Chapters 7, 8, 12

2. Microscopes Light microscopes: cells and big organelles
Electron microscopes: smaller cells, smaller organelles, bacteria, viruses, small molecules

3. Prokaryotes vs. eukaryotes
No nucleus
No membrane bound organelles
Small, simple
Only ribosomes
DNA circular
Nucleus
Membrane bound organelles
Bigger, complex
DNA is linear in strands

5. Nucleus Contains DNA and nucleolus Nucleolus makes ribosomal subunits
Nucleus is surrounded by nuclear envelope
Envelope has pores through which ribsomes and RNA can exit and messengers can enter

7. Ribosomes
Free ribosomes – float in cytoplasm and make proteins designed to stay in cell
Bound ribosomes – located on E.R. and make proteins designed to be exported out of cell
Each ribosome is made of 2 subunits
Prokaryotes and eukaryotes have different subunits

9. Endoplasmic reticulum
“network within cytoplasm”
Smooth E.R. = no ribosomes
Make lipids, carbohydrate metabolism, detoxification of drugs and poisons
Rough E.R. = ribosomes
Makes proteins to be secreted, folds them, and sends them to Golgi

12. Golgi apparatus
Manufacturing, warehousing, sorting, and shipping center
Flattened membranous sacs with two sides (receiving/cis and shipping/trans)
Ships products in vesicles which can fuse with membrane and be released

15. Lysosomes Membrane bound sac of hydrolytic enzymes Recycling center
Breaks down macromolecules and recycles old, dead organelles

17. Vacuoles Membrane bound storage sacs Food vacuoles
Contractile vacuoles pump water out
Central vacuole in plants

19. Mitochondria Site of cellular respiration (energy!)
One large one or hundreds of small ones
Double membrane (outer and inner)
2 compartments (intermembrane space and matrix)

21. Chloroplasts Site of photosynthesis
Stacks of membranes called thylakoids = granum (grana)
Stroma is fluid filled cavity
Thylakoids have the chlorophyll

23. Cytoskeleton Provides structural support Aids in cell motility
Microtubules: cell shape, cilia/flagella, chromosome movement in mitosis, organelle movement)
Microfilaments: cell shape, muscle contraction, pseudopodia, cleavage furrow
Intermediate filaments: cell shape, organelle anchoring

25. Plasma membrane Fluid mosaic model Phospholipid bilayer
Cholesterol helps maintain fluidity
Proteins function as cell surface receptors, channels, enzymes, cell-cell recognition
Carbohydrates serve as flags for cell recognition

28. Transport
Passive transport: molecules move down concentration gradient (requires no NRG)
Diffusion, osmosis, facilitated diffusion (help of a protein)
Active transport: against gradient requires energy
Endocytosis (phago, pino, receptor mediated)
exocytosis

31. Osmosis Hypertonic: higher concentration of solutes
Water leaves, cell shrivels
Hypotonic: lower concentration of solutes
Water enters, cell swells and maybe bursts
Isotonic: equal solute concentrations

34. Cell Division Reproduction, growth, repair
Results in formation of identical cells with identical DNA
Occurs in somatic cells
Mitosis: division of nucleus
Cytokinesis: division of cytoplasm

35. DNA and cell division DNA is replicated during S phase of interphase
Homologous chromosomes (mom’s and dad’s copy of each chromosome)
Sister chromatids: when each chromosome gets copied and connected together to go through mitosis

36. Cell Cycle
Interphase: accounts for most of the cycle (includes growth/gap G1/G2 phase and DNA synthesis S phase)
M phase (mitosis)
Cytokinesis
Cell cycle checkpoints

38. Mitosis
Prophase: chromatin condenses into chromosomes, mitotic spindle forms
Prometaphase: centrioles opposite poles, nucleus disappears
Metaphase: metaphase plate, chromosomes lined up at center
Anaphase: sister chromatids separate
Telophase: chromsomes separate to poles, nucleus begins to reform

40. Cytokinesis
Animals: cleavage furrow pinches off cells via contracting ring of microfilaments
Plants: cell plate forms between cells and creates new cell wall via delivery from vesicles carrying cell wall parts

42. Cell Cycle Regulation
Checkpoint: critical point where stop and go signals regulate cell cycle
Has all DNA been copied? Are there errors?
Is the cell big enough? Have all the organelles been copied?
Cancer: many mutations cause cells to bypass checkpoints and divide out of control