Alan Bio Note

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Alan's Biology Notes

Chapter 1 – Basis of Life
Ingestion – acquisition of food
Assimilation – building of new tissues from digested food
Monosaccharide – (carb) single sugar subunit
Polysaccharide – (carb) polymer, insoluble in water; ex: glycogen / cellulose Lipids – (2:1 H/O ratio) 3 FA bonded to glycerol; chief means of food storage · Major component of adipose tissue
· Steroids, waxes, carotenoids, porphyrins
Proteins - polymers of AA joined by peptide bond / 1* = AA sequence, 2* = folding (alpha beta) · Hormones (ACTH & insulin), Enzymes, structural pro (collagen), transport (hemoglobin), antibodies Enzymes – lower activation E & inc. rate of rxn / do not affect overall E · Higher temp = inc enzyme action / optimal pH = 7.2 (except pepsin & pancreas) · Competitive inhibitors compete w/ substrate for binding at ACTIVE site; can be overcome by adding more substrate; Vmax not affected · Noncompetitive inhibitors bind at allosteric site; diminishes Vmax Prokaryotes – bacteria, cell wall, NO nucleus, NO memb-bound organelles, ribosomes (no mem), mesosomes (invaginations of membrane) Eukaryotes – cell wall in fungi & plants, nucleus, membrane-bound organelles Centrioles – microtubule involved in spindle organization during cell division/ NO membrane Centromere – near middle of eukaryotic chromosomes where spindle fibers attach Lysosome – membrane bound, involved in ingestion / hydrolytic enzymes Mitochondria – exhibit maternal inheritance

desmosomes = “spot welds”; attach cells together and give cells mechanical strength (ex. skin cells) Tight junctions = seal the spaces b/w cells and prevent cell leakage (ex. intestinal cells) Gap junctions = allow cells to exchange nutrients and for molecular communication Endosymbiotic Theory – mitochondria and chloroplasts originated as independent unicellular organisms living in symbiosis with larger cells Fluid Mosaic – lipids and proteins are free to move back and forth fluidly; diffuse laterally · Integral Membrane are embedded in membrane by hydrophobic interactions · Peripheral are stuck to integral membrane proteins by H bonding Cell surface Receptors – type of integral membrane protein; three types: ligand-gated (open ion channel), catalytic, and G-protein G-Protein – use secondary messengers such as cAMP which amplify signal

Chapter 2 – Reproduction
S phase – replicate genome (create chromatids)
G1 & G2 phase – gap phases
Mitosis – 2N=>2N, occurs in all dividing cells; 10% of cell cycle 1. Interphase – replication of genetic material resulting in sister chromatids 2. Prophase – chromosomes condense; spindles form

3. Metaphase – chromosomes align at plate
4. Anaphase – sister chromatids separate; shortest phase
5. Telophase – new nuclear membranes form (cleavage furrow forms); spindles disappear * sequence = S, G2, P, M, A, T, G1
* Plants lack centrioles and divide by cell plate not cleavage furrow

Meiosis – occurs in sex cells, homologous chromosomes pair at meta plate (tetrads), crossing over can occur, 2N=>N - First Meiotic Division produces 2 daughter cells w/ N chromosomes w/ sister chrom 1. Prophase – chromatids of homologous chromosomes exchange genetic material (crossing over) 2. Metaphase – tetrads align at plate (synapsis); each pair attaches to a separate spindle 3. Anaphase – homologous pairs pulled to opposite poles (disjunction) / distribution to the two daughter cells is random w/ respect to parental origin 4. Telophase – nuclear membrane forms around each nucleus

- Second division is very similar to mitosis. Note that only one becomes functional gamete in females chiasmata – X-shaped region b/w diff. chromatids of homologous chromosomes kinetichore – specialized group of proteins and DNA on a chromatid to which several spindle microtubles are attached; found within the centromere of each chromosome Synapsis – pairing of homologous of chromosomes during meiosis I inversion – chromosomal segment turned 180o...
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