Midterm Bio Review PDF

Microscopy Approx. size ranges of prokaryotic and eukaryotic cells (μm) ○ prokaryotic = 0.1 - 10 μm ○ eukaryotic 10-100 (animal 10-30; plant 10-100) μm Minimum object size visible to human eye ○ 100 μm (0.1mm) The criteria of an effective microscope ○ Magni...

Microscopy Approx. size ranges of prokaryotic and eukaryotic cells (μm) ○ prokaryotic = 0.1 - 10 μm ○ eukaryotic 10-100 (animal 10-30; plant 10-100) μm Minimum object size visible to human eye ○ 100 μm (0.1mm) The criteria of an effective microscope ○ Magnification - increase in size ○ Resolution and LoR Resolution - distinguish between 2 objects. LoR - smallest distance apart to distinguish 2 separate objects (smaller, stronger) ○ Contrast - difference between object and background Differences Between Optical and Electron Microscopes ○ Magnification: Optical: Up to 1000x to 2000x. Electron: Up to 1,000,000x or more. ○ Limit of Resolution: Optical: ~0.2 μm. Electron: ~0.2 nm. ○ Source of Illumination: Optical: Beam of light. Electron: Electron beams. Confocal microscope ○ You can pick a focal plane of the specimen, making desired object clearer.  Wavelength ○ longer wavelength, lower energy ○ shorter wavelength, higher energy Visible spectrum: 380 - 740 nm Fluorescence: absorb light -> emit light at lower energy (longer wavelength) fluorescein isothiocyanate (FITC) - 495nm -> 519 nm Chemistry of the Cell Aldoses vs. Ketoses ○ Aldose; outside ○ Ketose; inside Acid vs. Base ○ acid = proton donor & ph < 7 ○ base = proton acceptor or releases hydroxide ions (OH-) & ph > 7 The periodic table ○ metals and non-metals: metal = group 1-2; cation (positive +); lose electrons nonmetal = group 15-17; anion (negative -); gain electrons Electron Shell Capacity 1st = 2 electrons. subsequent shells = 8 electrons.  Covalent vs. Ionic Bonds ○ Non-polar Covalent: 0 - 0.4 (Equal sharing of electrons) ○ Polar Covalent: 0.5 - 1.8 (Shared unequally between non-metals) ○ Ionic: 1.9-2.3 (Completely Transferred) Fluorine - 3.98 electronegativity Hydrogen bonds: ○ Oxygen (O) or Nitrogen (N) partial negative charge. ○ Hydrogen (H) partial positive charge. Special properties of water ○ pH = 7 ○ density of ice relative to water = ice is less dense because bonds spread out ○ most dense at 4°C ○ high surface tension ○ hydrophilic solutes Macromolecules Polymerization vs. De-polymerization ○ Polymerization: Small molecules (monomers) combine chemically to produce long chains (polymers). Needs energy Anabolic process - polymer growth Condensation - produces water  ○ De-polymerization: Breaking down of polymers into monomers. Energetically favorable. Spontaneous. Catabolic process - polymer breaks down Hydrolysis - consumes water Structural Isomers ○ Same chemical formula - Different atom arrangement/structure. α- and β-Glucose Isomers ○ Alpha glucose - parallel hydroxyl groups ○ Beta glucose - hydroxyl group mirrored to other side Glucose Disaccharides ○ Maltose = glucose + glucose ○ Lactose = galactose + glucose ○ Sucrose = glucose + fructose D vs. L sugar enantiomers ○ D (dexter) or L (laevus) - naturally found in D form Glycogen ○ Branched ○ Cytoplasm (liver and muscle cells) ○ Rapidly catabolized if energy needed Cellulose ○ Unbranched ○ β - 1,4 glycosidic bonds  Lipids ○ Don’t form polymers ○ Hydrophobic ○ Insoluble in aqueous solutions Phospholipid Bilayer ○ Head - phosphate group; hydrophilic; polar ○ 2 Tails - fatty acid; hydrophobic ○ Bound to a glycerol backbone Steroids ○ 4 rings carbon structure ○ Influence membrane fluidity ○ Signaling molecules (cholesterol, estrogen, testosterone, cortisol) Cholesterol ○ Major sterol in animal cells ○ Stiffens phospholipid bilayer ○ Connects to adjacent polar heads ○ Reduces permeability of small water-soluble molecules Fatty Acids ○ Saturated  Can be stacked Higher melting point Solid at room temp. ○ Un-saturated Loose tails (has “kinks” in hydrocarbon chain) Reduced compressibility Liquid at room temp. Proteins ○ Primary - amino acid sequence ○ Secondary - polypeptide backbone atomic interactions α-helices β-pleated sheets ○ Tertiary - amino acid side chain interactions ○ Quaternary - multiple peptide chain interactions Nucleotides vs. nucleosides ○ Nucleotide - all parts (includes phosphate group) ○ Nucleoside - nitrogenous base & sugar (NO phosphate group) Deoxyribose vs. Ribose sugars ○ glycosidic bonds at carbons 1, 2, 3, and 5. ○ Ribose has 2 hydroxyl groups  ○ Deoxy has 1 hydroxyl group 5 Nitrogenous Bases ○ Pyrimidines (CTU) - 1 nitrogen-containing ring Cytosine (C) Thymine (T) Uracil (U), found in RNA ○ Purines (AG) - 2 nitrogen-containing ring Adenine (A) Guanine (G) Membrane Transport Solutes with HIGH permeability ○ Small ○ Uncharged ○ Non-polar Solutes with LOW permeability ○ Large ○ Charged (ions) ○ Polar Sodium-Potassium Antiporter  ○ 3 - Sodium (Na) goes in ○ 2 - Potassium (K) goes out ○ ATP is hydrolyzed; turned to ADP ○ Contributes to a NEGATIVE resting potential within the cell Tonicity - Water flows from hypo to hyper ○ Hypotonic - low solute ○ Hypertonic - high solute ○ Isotonic - equal solute Cell Tonicity ○ Animal Cell Hypotonic - Lysed Hypertonic - Shriveled Isotonic - Normal ○ Plant Cell Hypotonic - Turgid Hypertonic - Plasmolyzed Isotonic - Flaccid Facilitated Diffusion (Proteins) ○ Transporter - bind solute and change direction uniporter - single one-way symporter - two lane one-way anti-porter - two-way  ○ Channel - always open or closed Passive vs. Active Transport ○ Passive - down electrochemical gradient; no energy required ○ Active - AGAINST electrochemical gradient; requires energy Diffusion - Passive movement down an electrochemical gradient ○ Osmosis - net movement of water; semi-permeable membrane Aquaporins - channel proteins that facilitate osmosis Endocytosis - stuff goes in the cell ○ Phagocytosis - eats stuff outside the cell Phagocytic cells eat foreign particles; relies on pathogenic antibodies and cell receptors ○ Pinocytosis - cellular drinking; invagination; small particles only (noob endocytosis) ○ Receptor Mediated Endocytosis (RME) - macromolecules bind to receptors on cell’s surface (pino but highly selective + extra steps) Organelles Rough E.R. - has ribosomes on the surface / undergoes protein modification / continuous with nuclear membrane Smooth E.R. - lipid / fat production  Cytoskeleton ○ Intermediate Filaments - structural support ○ Microfilament - cell shape ○ Microtubules - inner cell transport, cell division, cell movement Lysosome - breaks down stuff (using hydrolase) ○ pH - 5 ○ Damaged organelles and food particles are degraded to recycle components Peroxisome ○ produces hydrogen peroxide (H2O2) ○ Uses enzyme CATALASE for peroxidation catalysis ○ lipid oxidation ○ Important in liver and kidney cells Nuclear envelope - holds nucleus ○ Nuclear pore - door for nucleus ○ Nuclear lamina - structural support for envelope ○ Outer membrane is continuous with Endoplasmic Reticulum Nucleolus - ribosome biogenesis Vesicles ○ Transport - transport cargo between organelles ○ Secretory - Golgi apparatus to plasma membrane out of the cell ○ Endocytic - endocytosis Cytoplasm - contains everything outside the nucleus  Cytosol - funny cell gel Plasma Membrane - keeps stuff in the cell ○ Responds to signals with signaling proteins. ○ Carbohydrate groups are involved in cell signaling Eukaryotic Cell Division Central Dogma ○ DNA Transcription -> RNA Translation (mRNA) -> Protein Centromere ○ Small ring that connects two haploid cells Human Gamete Cell ○ 23 per haploid cell (sperm / egg) Human Non-Gamete Cell ○ 46 Cell Cycle (Typically lasts ~24 hours Cell Cycle Checkpoints: Start Transition  G2-to-M Transition Metaphase to Anaphase ○ Interphase ~23 hours G1 - end of mitosis S - DNA Replication G2 - End of Replication; start of Mitosis ○ Mitosis ~1 hour Chromosomes separate Cells divide DNA Replication Enzymes / Proteins ○ dna helicase: unwinds dna (uses atp) ○ binding protein: helps stabilize dna ○ primase: makes rna primers to begin polymerase (5' to 3') ○ dna polymerase: makes 5' - 3' activity. goes along 3' - 5' strand. can remove wrong nucleotides along 3' - 5'. ○ polymerase α: makes dna on lagging strands ○ polymerase δ: makes Okazaki fragments and replaces RNA primers ○ polymerase ε: makes leading strand ○ dna ligase: fills in lagging strands Continuous vs. Discontinuous Synthesis ○ DNA polymerase ONLY synthesizes in 5’-to-3’ ○ Lagging strand is called Okazaki fragments; filled in with ligase  Replication Fork ○ Contains both leading and lagging strand Origins of replication ○ Primase makes RNA primers (primase moves along 3’-to-5’) Mitosis: ○ Prophase chromosome condensing mitotic spindle on ends Centrosomes duplicate then move to ends of cell ○ Prometaphase nuclear envelope no more mitotic spindle attach to kinetochores ○ Metaphase chromosomes align ○ Anaphase splits chromosomes ○ Telophase decondensation split ends make nuclear envelopes each contractile ring formation