Animations and Videos • Bozeman - AP BIO Labs Review
Lab 1: Diffusion & Osmosis • Description • dialysis tubing filled with starch-glucose solution in beaker filled with KI solution • potato cores in sucrose solutions
Lab 1: Diffusion & Osmosis • Concepts • semi-permeable membrane • diffusion • osmosis • solutions • hypotonic • hypertonic • isotonic • water potential
Lab 1: Diffusion & Osmosis • Conclusions • water moves from high concentration of water (hypotonic=low solute) to low concentration of water (hypertonic=high solute) • solute concentration & size of molecule affect movement through semi-permeable membrane
When a solution such as that inside dialysis tubing is separated from pure water by a selectively-permeable membrane water will move by osmosis from the surrounding area where the water potential is higher into the cell where water potential is lower due to the presence of solute. The movement of water into the cell causes the cell to swell and the cell membrane pushes against the cell wall to produce an increase in pressure (turgor). This process will continue until the water potential of the cell equals the water potential of the pure water outside the cell. At this point, a dynamic equilibrium is reached and net water movement will cease.
Animations and Videos • Bozeman - AP BIO Lab 1 - Diffusion and Osmosis • AP LAB 1 - Diffusion and Osmosis • AP WEB LAB - Osmosis and Diffusion
Lab 2: Enzyme Catalysis • Description • measured factors affecting enzyme activity • H2O2 H2O + O2 • measuredrate ofO2 production catalase
Lab 2: Enzyme Catalysis • Concepts • substrate • enzyme • enzyme structure • product • denaturation of protein • experimental design • rate of reactivity • reaction with enzyme vs. reaction without enzyme • optimum pH or temperature • test at various pH or temperature values
Lab 2: Enzyme Catalysis • Conclusions • enzyme reaction rate is affected by: • pH • temperature • substrate concentration • enzyme concentration calculate rate?
In the first few minutes of an enzymatic reaction, the number of substrate molecules is usually so large compared to the number of enzyme molecules that changing the substrate concentration does not (for a short period at least) affect the number of successful collisions between substrate and enzyme. During this early period, the enzyme is acting on substrate molecules at a constant rate. The slope of the graph line during this early period is called the initial velocity of the reaction. The initial velocity, or rate, of any enzyme catalyzed reaction is determined by the characteristics of the enzyme molecule. It is always the same for an enzyme and its substrate as long as temperature and pH are constant and substrate is present in excess. Also, in this experiment the disappearance of the substrate is essential in this reaction. Eventually, the rate of the reaction levels off.
Animations and Videos • Bozeman - AP BIO Lab 2 - Enzyme Catalyst • AP LAB 2 - Enzyme Catalyst • AP WEB LAB - Enzyme Catalyst
Lab 3: Mitosis & Meiosis • Description • cell stages of mitosis • exam slide of onion root tip • count number of cells in each stage to determine relative time spent in each stage • crossing over in meiosis • farther gene is from centromere the greater number of crossovers • observed crossing over in fungus, Sordaria • arrangement of ascospores
I P M A T Lab 3: Mitosis & Meiosis • Concepts • mitosis • interphase • prophase • metaphase • anaphase • telophase • meiosis • meiosis 1 • meiosis 2 • crossing over • tetrad in prophase 1
Lab 3: Mitosis & Meiosis • Conclusions • Mitosis • longest phase = interphase • each subsequent phase is shorter in duration • Meiosis • 4:4 arrangement in ascospores • no crossover • any other arrangement • crossover • 2:2:2:2 or 2:4:2
total crossover % crossover = total offspring % crossover distance fromcentromere = 2 Sordaria analysis
The relative lengths of the mitotic stages are: 53.4% prophase, 17.4% metaphase, 16.8% anaphase and 12.4% telophase. Meiosis is important for sexual reproduction because it reduces the chromosome number by half and it also results in new combinations of genes through independent assortment and crossing over, followed by the random fertilization of eggs by sperm.
Animations and Videos • Bozeman - AP BIO Lab 3 - Mitosis and Meiosis • AP LAB 3 - Mitosis and Meiosis • Bozeman - The Sodaria Cross • AP WEB LAB – Mitosis • AP WEB LAB - Meiosis
Lab 4: Photosynthesis • Description • determine rate of photosynthesis under different conditions • light vs. dark • boiled vs. unboiled chloroplasts • chloroplasts vs. no chloroplasts • use DPIP in place of NADP+ • DPIPox = blue • DPIPred = clear • measure light transmittance • paper chromatography to separate plant pigments
Lab 4: Photosynthesis • Concepts • photosynthesis • Photosystem 1 • NADPH • chlorophylls & other plant pigments • chlorophyll a • chlorophyll b • xanthophylls • carotenoids • experimental design • control vs. experimental
Lab 4: Photosynthesis • Conclusions • Pigments • pigments move at different rates based on solubility in solvent • Photosynthesis • light & unboiled chloroplasts produced highest rate of photosynthesis
Animations and Videos • Bozeman - AP BIO Lab 4 - Plant Pigments and Photosynthesis • AP LAB 4 - Plant Pigments and Photosynthesis • Using a Spectrophotometer • AP WEB LAB – Pigments • AP WEB LAB - Photosynthesis
The solvent moves up the paper by capillary action, which occurs as a result of the attraction of solvent molecules to the paper and the attraction of solvent molecules to one another. As the solvent moves up the paper, it carries along any substances dissolved in it, in this case pigments. The pigments are carried along at different rates because they are not equally soluble in the solvent and because they are attracted, to different degrees, to the cellulose in the paper through the formation of hydrogen bonds. Also, as the DPIP is reduced and becomes colorless, the resultant increase in light transmittance is measured over a time course using a spectrophotometer.
Lab 5: Cellular Respiration • Description • using respirometer to measure rate of O2 production by pea seeds • non-germinating peas • germinating peas • effect of temperature • control for changes in pressure & temperature in room
Lab 5: Cellular Respiration • Concepts • respiration • experimental design • control vs. experimental • function of KOH • function of vial with only glass beads
Lab 5: Cellular Respiration • Conclusions • temp = respiration • germination = respiration calculate rate?
Germinating peas respire and need to consume oxygen in order to continue the growing process. Pea seeds are non-germinating and do not respire actively. These seeds are no longer the site of growth and thus do not need oxygen for growth. In consideration to temperature, at higher temperatures more oxygen is consumed which means more respiration is occurring. 686 kilocalories are released during respiration. When temperature decreases molecular motion slows down and respiration decreases because less energy is made available.
Animations and Videos • Bozeman - Lab 5 - Cell Respiration • Bozeman - AP BIO Lab 5 - Cell Respiration • AP LAB 5- Cell Respiration • AP WEB LAB - Cell Respiration
Lab 6: Molecular Biology • Description • Transformation • insert foreign gene in bacteria by using engineered plasmid • also insert ampicillin resistant gene on same plasmid as selectable marker • Gel electrophoresis • cut DNA with restriction enzyme • fragments separate on gel based on size
Lab 6: Molecular Biology • Concepts • transformation • plasmid • selectable marker • ampicillin resistance • restriction enzyme • gel electrophoresis • DNA is negatively charged • smaller fragments travel faster
Lab 6: Transformation • Conclusions • can insert foreign DNA using vector • ampicillin becomes selecting agent • no transformation = no growth on amp+ plate
Lab 6: Gel Electrophoresis • Conclusions DNA = negatively charged correlate distance to size smaller fragments travel faster & therefore farther
Bacterial Transformation-Ampicillin Resistance: In this exercise, we will introduce competent E. Coli cells to take up the plasmid pAMP, which contains a gene for ampicillin resistance. Normally, E. Coli cells are destroyed by the antibiotic ampicillin, but E. Coli cells that have been transformed will be able to grow on agar plates containing ampicillin. Thus, we can select for transformants; those cells that are not transformed will be killed by ampicillin; those that have been transformed will survive.
Restriction Enzyme Cleavage of DNA: Restriction endonuclease recognizes specific DNA sequences in double-stranded DNA and digests the DNA at these sites. The result is the production of fragments of DNA of various lengths corresponding to the distance between identical DNA sequences within the chromosome. By taking DNA fragments and systematically reinserting the fragments into an organism with minimal genetic material, it is possible to determine the function of particular gene sequences
Electrophoresis: Fragments of DNA can be separated by gel electrophoresis when any molecule enters the electrical field, the mobility or speed at which it will move is influenced by the charge (negative charges travel to positive/top pole of gel), the density of the molecule, (the smaller the molecule, the faster it travels), the strength of the electrical field, and the density of the medium (gel) which it is migrating.
Animations and Videos • Bozeman - AP BIO Lab 6 - Molecular Biology • AP LAB 6 - Molecular Biology • AP WEB LAB - Molecular Biology
Lab 7: Genetics (Fly Lab) • Description • given fly of unknown genotype use crosses to determine mode of inheritance of trait
Lab 7: Genetics (Fly Lab) • Concepts • phenotype vs. genotype • dominant vs. recessive • P, F1, F2 generations • sex-linked • monohybrid cross • dihybrid cross • test cross • chi square
Lab 7: Genetics (Fly Lab) • Conclusions: Can you solve these? Case 1 Case 2
From this lab, you will be able to find genotypes and phenotypic expression within a fruit fly. Also, recessive genes and mutations will be revealed as the student crosses a variety of Drosophila alleles. For example, if a female carrier for an x-linked, recessive trait, was crossed with a male without the recessive trait the results would be: • ½ males with x-linked trait ½ males without • ½ female carriers ½ females without • 0 females express sex linked traits
Animations and Videos • Bozeman - AP BIO Lab 7 -Genetics of Organisms • AP LAB 7 - Genetics of Organisms • AP WEB LAB - Genetics of Organisms • Bozeman - Chi-squared Test
Lab 8: Population Genetics • Description • simulations were used to study effects of different parameters on frequency of alleles in a population • selection • heterozygous advantage • genetic drift
Lab 8: Population Genetics • Concepts • Hardy-Weinberg equilibrium • p + q = 1 • p2 + 2pq + q2 = 1 • required conditions • large population • random mating • no mutations • no natural selection • no migration • gene pool • heterozygous advantage • genetic drift • founder effect • bottleneck
Lab 8: Population Genetics • Conclusions • recessive alleles remain hidden in the pool of heterozygotes • even lethal recessive alleles are not completely removed from population • know how to solve H-W problems! • to calculate allele frequencies, use p + q = 1 • to calculate genotype frequencies or how many individuals, use, p2 + 2pq + q2 =1