Biology Exam Note

MISCELLANEOUS INFO ● Nonpolar covalent bonds- equal electron sharing ● Polar covalent bonds- unequal electron sharing ● WATER IS POLAR ● Hydrogen bonds in water ● Atomic number-number of protons ● Mass number-protons+neutrons PROPERTIES OF WATER ● Cohesion ○ Surface tension ● Adhesion ○ Capillary action ● Universal solvent ● High specific heat ● Less dense than ice ACIDS/BASES ● Acids increase H+ ● Bases increase OH● pH scale 0-14 CARBS ● C1, H2, O1 ● Monosaccharides ○ Glucose ○ Fructose ○ Galactose ● Disaccharides ○ Sucrose ○ Maltose ○ Lactose ● Polysaccharides ○ Cellulose ○ Chitin ○ Glycogen ○ Starch LIPIDS ● Triglyceride ○ Glycerol ○ 3 fatty acids ● Saturated fats ○ “Bad” ○ Single bonds only ○ Animal fats ○ Solid at room temperature ● Unsaturated fats ○ “Good” ○ Double bonds ○ Fruits/vegetables/fish/oils ○ Liquid at room temperature ● Trans fats ○ Artificially hydrogenated ● Phospholipid Bilayer ○ Cell membrane ○ Mosaic ○ Hydrophilic head ■ Phosphate group ■ Glycerol ○ Hydrophobic tail ■ One saturated fatty acid ■ One unsaturated fatty acid ● Steroids ○ Four fused rings ○ Testosterone/Estrogen ○ Cholesterol ■ High levels not good ● Waxes ● Sudan IV PROTEINS ● Amino acids ● Biuret's test ● Polypeptide-C→N ● Structure ○ Primary- order of amino acids ○ Secondary- alpha helix/beta sheets ○ Tertiary- 3D structure (hydrogen bonds) ○ Quaternary- More than 1 polypeptide chain ● Denaturation ○ Salt ○ pH ○ Heat NUCLEIC ACIDS ● Polymers of nucleotides ● DNA/RNA ● 3 parts ○ Phosphate group ○ Ribose/Deoxyribose ○ Nitrogenous base ● DNA ○ Deoxyribose ○ Pyrimidines ■ Thymine ■ Cytosine ○ Purines ■ Adenine ■ Guanine ○ Sugar-phosphate backbone ● RNA ○ Ribose ○ Pyrimidines ■ Urasil ■ Cytosine ○ Purines (same as DNA) ● ATP (Adenosine Triphosphate) ○ Energy released during hydrolysis ○ Hydrolysis- ATP→ADP ENZYMES ● Catalyze reactions ● PROTEINS ● Act on substrates ● End in -ase ● Active site ● Can be reused ● Optimal pH/temperature ● Competitive/Noncompetitive inhibition CELL MEMBRANE ● Barrier ● Controls what enters and leaves the cell ● Gives and receives signals ● SEMI-PERMEABLE ● Jobs ○ Barrier ○ Communication ○ Recognition ○ Enzymes ○ Connection ● Phospholipid ● Phosphate+fatty acids ● Fluid mosaic ● Phospholipids+embedded proteins ● Passive transport ○ Selectively permeable ○ No energy (down concentration gradient) ○ Simple diffusion ● ● ○ Small, nonpolar, fats ○ Facilitated diffusion-passive transport that needs channels Carrier proteins ○ Active and passive transport ○ Change shape Osmosis ○ Water diffusion through membrane ○ Salt sucks ○ Solute is dissolved/Solvent does dissolving ○ Hypotonic has more water and less solute ○ Hypertonic has less water and more solute ○ Water moves from hypo→hyper ○ Isotonic- equal hypo/hyper ○ Aquaporins Sodium/Potassium Pump-active Exo/endocytosis Pinocytosis-water Phagocytosis-solids Pinches off membrane ● ● ● ● ● DNA ● Central dogma ○ DNA→RNA→Proteins ● Transcription ● Promotor starts ● Exons kept during splicing ● Translation ● Trp operon-stopped by tryptophan ● Lac operon-activated by lactose DNA REPLICATION ● Helicase unzips DNA ● Primase starts replication ● Polymerase adds bases to the leading strand ● Lagging strand-Okazaki fragments ● Ligase seals up new DNA MITOSIS ● Cell cycle ○ G1, S, G2, Mitosis ○ G1-cell grows ○ S-DNA replication ○ G2-cell grows ○ Apoptosis is programmed cell death ● Prophase ○ ○ Nucleus breaks ○ Spindle fibers form ● Metaphase ○ ○ Spindle fibers attach to centromeres ○ Chromosomes line up in the middle ● Anaphase ○ ○ Fibers contract ○ Sister chromatids are pulled apart to opposite ends of the cell ● Telophase ○ ○ Membranes form ○ Chromosomes unwind ○ Spindle fibers disappear ○ Cytokinesis-splitting of the cytoplasm ● Each daughter cell has identical chromosomes ● Cancer-cell cycle loses control ● (Proto)oncogenes/tumor suppressors MEIOSIS ● Every human has 46 chromosomes; 23 pairs ● Gametes-one from each pair ● Zygote-first 46 chromosome cell ● Somatic cells are diploid ● Gametes are haploid ● Homologous chromosomes ○ Same types of genes ○ NOT IDENTICAL ● Meiosis I ● Prophase I ○ Tetrads form ○ Crossing over occurs-genetic variation ● Metaphase I ○ Independent assortment-variation ● Anaphase I ○ Chromosomes are pulled apart ● Telophase I ○ Cytokinesis ○ NO INTERPHASE ○ NO DUPLICATION ● Meiosis II ○ Just like mitosis ○ 4 gametes ● Spermatogenesis ● Oogenesis ○ One large egg ○ 3 polar bodies ● 4 haploid gametes ● Mistakes in meiosis ○ Nondisjunction ■ Down syndrome ● Trisomy 21 ■ Klinefelter’s ● Xxy ● Sterile male ■ Turner ● XO ● Sterile ○ ○ ■ Edwards ● Trisomy 18 ■ Patau ● Trisomy 13 Translocation Insertion/deletion ■ Prader-willi ● Part of 15 deleted ■ Williams ● Part of 7 deleted Inversion Monosomies Trisomies ○ ○ ○ GENETICS ● Multiple alleles, one trait ● Blood types ○ AA/AO-A ○ BB/BO-B ○ AB-AB ○ OO-O ○ Rh+Rh+/Rh+Rh- → + ○ Rh-Rh- → ● Incomplete dominance ○ Blend ○ Each allele is expressed as a capital letter ○ 100% pink R R W CRCW CRCW W CRCW CRCW ● Codominance ○ Both traits are dominant ○ DO NOT BLEND ○ Traits show separately ● X-linked traits ○ Men have a higher chance of having ● Polygenic ○ Many genes with many alleles each ○ Expressed as gradient ○ Pleiotropy- one gene, multiple traits EVOLUTION ● Charles Darwin ● Theory of Evolution-NATURAL SELECTION ● Organisms change over time ● No acquired characteristics ● Darwin went to the Galapagos ● He discovered that all finches came from one ancestral species ● He wrote The Origin of Species ○ VARIATION exists among species ○ COMPETITION for resources ○ Some dies, some SURVIVED ○ Those who survived were able to REPRODUCE ● Adaptations-favorable variations ● Evidence ○ Fossils ○ Homologous structures ○ Vestigial organs ○ DNA ○ Embryonic development ○ Direct observation ● Microevolution-evolution within a population ● Gene flow-movement of alleles (migration) ● Bottleneck-reduction of population ● Founder effect-high gene frequency in isolated population ● ● ● ● Speciation-1 species→2+ species ○ Allopatric-geographic isolation ○ Sympatric-no geographic isolation ● Coevolution-out-evolve each other ● Adaptive radiation/speciation? CELLULAR RESPIRATION ● C6H12O6 + 6O2→6CO2 + 6H2O + 36 ATP ● Glycolysis ○ ○ Inputs ■ 1 glucose ■ 2 ATP ■ 2 NAD+ ○ Outputs ■ 4 ATP (net 2) ■ 2 NADH (next steps) ■ 2 pyruvate (next steps) ■ Water ● Transition/Krebs cycle ○