BIO 111 TAMU LAB EXAM 1 QUESTIONS AND ANSWERS 2024.

Accuracy a measure of how close a result matches a correct or standard value. For example, how close a dart is to the bullseye in a dartboard is an indicator of accuracy. Precision a measure of variability. For example, three darts placed close together on a dartboard indicate high precision, but if this cluster of darts is far from the bullseye it would also indicate low accuracy. Brainpower Read More Previous Play Next Rewind 10 seconds Move forward 10 seconds Unmute 0:01 / 0:15 Full screen an ideal experiment yields results with both high accuracy and high precision. Although biological and/or environmental conditions may limit one or both of these features, poor technique is an unacceptable source of errors. Aliquot a portion of something (noun); or to divide or transfer a portion of something (verb). For this lab, aliquot refers to an amount of liquid. Micropipette an instrument used to measure/deliver amounts of liquid with high accuracy and precision. Micropipettes are expensive so treat these with respect. Spectrophotometer: an instrument for measuring the intensity of light that is transmitted through a sample (transmittance) or absorbed by a sample (absorbance). In this lab, you will measure light absorbance at a defined wavelength. The use of a spectrophotometer is called spectrophotometry. Molar weight a measure of mass. By definition, a mole is 6x1023 objects (atoms, molecules, Aggies, etc.). The mass of an object is defined by its composition at the atomic level. Standard curve a graph in which properties of known samples are measured and plotted. The direct proportionality of these properties can then be used to determine the same information from unknown samples. In this lab, a standard curve of Absorbance versus protein concentration will be used to determine the concentration of protein in an unknown sample. Standard Curve Practice Problems Molar Weight Practice Problems Bradford Assay is an assay that uses Coomassie Blue dye to bind the common part of all proteins, that is the peptide backbone. By itself, Bradford reagent has a reddish-brown color and the highest absorbance (absorbance spectrum maximum) at 465 nm. Bradford reagent bound with proteins, however, is blue and has an absorbance spectrum maximum at 595 nm. As protein concentration increases, more of the protein-dye complex will be formed and the resulting solution will be a more intense blue color. Which statement correctly describes, in general, a blank used to 0 (zero) the spectrophotometer? The blank includes everything in your experimental samples except what you want to measure Which of these reagents binds to protein to create a color change that you can measure Braford reagent For the experiment measuring concentrations of BSA using spectrophotometry, the blank will include which of the following Bradford Reagent NaCl Enzymes Protiens and a Catalysts for chemical reactions in living things Define what enzymes bind too substrates, and enzymes only bind to very specific substrates Enzymes are effected by PH levals, Temperature, and the conentration of enzymes and substrates β-galactosidase enzyme that hydrolyzes lactose to form glucose and galactose why did there have to be orhto-nitrophenol added to the ONPG and glactose to measure it in a spectrometer? Orth-nitrophenol has a yellow color, and both ONPG and glactose are colorless Study how to calculate ONPG and Z buffers ----- Enzyme Activity formula (A420nm/time)x1000 Which of the following would not be expected to have an effect on the activity of ß-galactosidase? Absorbance BSA concentration true about spectrophotometers Can measure how much light passes through the sample (transmittance). Works by shining light of a specific wavelength through the sample. Can measure how much light is absorbed by a solution. Bacteria Used in Lab 2 Escherichia coli What is the purpose of lysis buffer in the experimental reactions? Breaks open cells by disrupting the cell membrane. What is cellular respiration an overarching term which includes all the processes a living organism uses to produce ATP (adenosine triphosphate). These processes include: glycolysis, fermentation, oxidation of pyruvate, and the Krebs cycle. Each of these processes/cycles requires multiple steps and reactions, involving many enzymes and reactions along the way. Example of anaerobic respiration fermentation, happens at end of glycosis example of aerobic respiration cellular respiration