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Module 1 Biotechnology Basics Copyright © Texas Education Agency 2009. All rights reserved. Lessons for Module 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Overview of Biotechnology Cell Structure and Function DNA Structure and Function Protein Synthesis Protein Structure and Function Math Skills Lab Overview Copyright © Texas Education Agency 2009. All rights reserved. Goals for Lesson 1.5 Identify significant figures Calculate in scientific notation Convert numbers in the metric system Describe units of concentration Perform calculations necessary for preparing stock solutions Calculate parallel dilution formulas Copyright © Texas Education Agency 2009. All rights reserved. Significant Figures All the numbers for which actual measurements are made plus one estimated number 1 2 You would estimate this measurement as 1.5 1 2 You would estimate this measurement as 1.48 Copyright © Texas Education Agency 2009. All rights reserved. Significant Figures Tells the person interpreting your data about the accuracy of the measuring instrument used to obtain the data Copyright © Texas Education Agency 2009. All rights reserved. Significant Figures Rules for counting sig figs 1. Digits other than zero are always significant. a. 96 = 2 sig figs b. 61.4 = 3 sig figs 2. Zeroes between 2 other sig figs are always significant. a. 5.029 = 4 sig figs b. 306 = 3 sig figs Copyright © Texas Education Agency 2009. All rights reserved. Significant Figures Rules for counting sig figs 3. Leading zeroes are never significant when they are to the left of non-zero numbers. a. 0.0025 = 2 sig figs b. 0.0821 = 3 sig figs 4. Trailing zeroes are only significant if there is a decimal present and they are to the right of nonzero numbers. a. 100 = 1 sig fig b. 100.0 = 4 sig figs c. 0.0820 = 3 sig figs Copyright © Texas Education Agency 2009. All rights reserved. Sig Fig Practice Significant Figures Rules for calculating with sig figs 1. In addition and subtraction, the answer should be rounded off so that it has the same number of decimal places as the quantity having the least number of decimal places. a. 1.1 + 225 = 226.1 = 226 (rounded to no decimal places) b. 2.65 – 1.4 = 1.25 = 1.3 (rounded to 1 decimal place) 2. In multiplication and division, the answer should have the same number of significant figures as the given data value with the least number of significant figures. a. 4.60 45 = 207 = 210 (rounded to 2 sig figs) b. 1.956 3.3 = 0.5927 = 0.59 (rounded to 2 sig figs) Copyright © Texas Education Agency 2009. All rights reserved. Scientific Notation A way to write very large and very small numbers A number in scientific notation is written in two parts, the coefficient and an exponent of 10 coefficient 5 x 1022 Copyright © Texas Education Agency 2009. All rights reserved. exponent of 10 Scientific Notation Changing standard numbers to scientific notation 1. Numbers greater than 10 a. Move decimal until only ONE number is to the left of the decimal. b. The exponent is the number of places the decimal has moved and it is POSITIVE. Ex. 125 = 1.25 102 15,000,000,000 = 1.5 1010 Copyright © Texas Education Agency 2009. All rights reserved. Scientific Notation Changing standard numbers to scientific notation 2. Numbers less than 1 a. Move decimal until only one number is to the left of the decimal. b. The exponent is the number of places the decimal has moved and it is NEGATIVE. Ex. 0.000189 = 1.89 10-4 0.5476 = 5.476 10-1 Copyright © Texas Education Agency 2009. All rights reserved. Scientific Notation Changing standard numbers to scientific notation 3. To change a number written in incorrect scientific notation: a. Move the decimal until only one number is to the left of the decimal. b. Correct the exponent. (remember: take away, add back) coefficient decreased by 2, so Ex. 504.2 106 = 5.042 108 The the exponent must increase by 2 0.0089 10-2 = 8.9 10-5 Copyright © Texas Education Agency 2009. All rights reserved. The coefficient increased by 3, so the exponent must decrease by 3 Scientific Notation Changing numbers in scientific notation to standard notation 1. 2. If the exponent is (+) move the decimal to the right the same number of places as the exponent. a. 1.65 101 = 16.5 b. 1.65 103 = 1650 If the exponent is (-) move the decimal to the left the same number of places as the exponent. a. 4.6 10-2 = 0.046 b. 1.23 10-3 = 0.00123 Scientific Notation Drill Copyright © Texas Education Agency 2009. All rights reserved. Scientific Notation Multiplication and division in scientific notation 1. To multiply numbers in scientific notation a. Multiply the coefficients. b. Add the exponents. c. Convert the answer to correct scientific notation. Ex: (2 109) x (4 103) = 8 x 1012 Copyright © Texas Education Agency 2009. All rights reserved. Scientific Notation Multiplication and division in scientific notation 2. To divide numbers in scientific notation a. Divide the coefficients. b. Subtract the exponents. c. Convert the answer to correct scientific notation. Ex: (8.4 106) (2.1 102) = 4 x 104 Multiplying and Dividing in Scientific Notation Copyright © Texas Education Agency 2009. All rights reserved. Scientific Notation Addition and Subtraction in Scientific Notation 1. Before numbers can be added or subtracted, the exponents must be equal. Ex. (5.4 103) + (6.0 102) = (5.4 103) + (0.6 103) = 6.0 103 Copyright © Texas Education Agency 2009. All rights reserved. Metric System Unit Unit Unit Unit Unit of of of of of length…..meter (m) mass ……gram (g) volume …liter (L) time …….second (s) temperature…degrees Celsius (°C) Copyright © Texas Education Agency 2009. All rights reserved. Metric System The metric system is based on units of 10. Prefix symbol Prefix name Prefix value Fraction or Multiple Power G giga one billion 1,000,000,000 109 M mega one million 1,000,000 106 k kilo one thousand 1000 103 1 10 BASIC UNIT: m, g, L, d deci 1/10 0.1 10-1 c centi 1/100 0.01 10-2 m milli 1/1000 0.001 10-3 µ micro 1/1,000,000 0.000 001 10-6 n nano 1/1,000,000,000 0.000 000 001 10-9 Copyright © Texas Education Agency 2009. All rights reserved. Metric System Converting measurements within the metric system is a simple matter of multiplying or dividing by 10, 100, 1000, etc. Even simpler, it is a matter of moving the decimal point to the left or right. Copyright © Texas Education Agency 2009. All rights reserved. Metric System One way to know where to place the decimal is to draw a "metric line" with the basic unit in the center, marking off six units to the left and six units to the right. To convert from one unit to another simply count the number of places to the left or right, and move the decimal in that direction that many places. Ex. 3 L = 0.003 kL Copyright © Texas Education Agency 2009. All rights reserved. Ex. 3 mg = 3000 µg Units of Concentration A solution is a homogeneous mixture of one substance (the solute) dissolved in another substance (the solvent). Concentration is a ratio of the amount of solute to the amount of solvent. Copyright © Texas Education Agency 2009. All rights reserved. Units of Concentration Molarity (M) is the most common unit of concentration Molarity is an expression of moles/Liter of the solute. Copyright © Texas Education Agency 2009. All rights reserved. Units of Concentration A mole is the SI unit of number of particles and can be used as an expression of the molecular weight of a substance. The formula weight of an element is expressed as grams/mole Copyright © Texas Education Agency 2009. All rights reserved. Units of Concentration The molar mass of a compound can be calculated by adding the molar mass of the individual elements. 22.99 + 35.45 = 58.44 g/mol Copyright © Texas Education Agency 2009. All rights reserved. Making Solutions You just calculated the molar mass of sodium chloride to be 58.44 g/mol. To determine how to make a stock solution of sodium chloride, use the formula: g = M x L x molar mass Copyright © Texas Education Agency 2009. All rights reserved. Making Solutions How many grams of NaCl would you need to prepare 500 mL of a 1 M solution? g = M x L x molar mass g = (1mol/L) (0.5L) (58.44g/mol) g = 29.22 g Copyright © Texas Education Agency 2009. All rights reserved. Making a Solution Diluting Solutions Once you have made a stock solution, you often will need to dilute it to a working concentration. To determine how to dilute the stock solution, use the formula: C1V1 = C2V2 Copyright © Texas Education Agency 2009. All rights reserved. C1 C2 V1 V2 – concentration of stock - concentration of diluted solution – volume needed of stock – final volume of dilution Diluting Solutions How many milliliters of a 1 M stock solution of NaCl are needed to prepare 100 ml of a 0.05 M solution? C1 V1 = C2 V2 (1)V1 = (0.05)(100) V1= 5 ml Dilutions Tutorial Copyright © Texas Education Agency 2009. All rights reserved. Resources Copyright © Texas Education Agency 2009. All rights reserved.