chapter 1 biochemistry study guide

8/9/2019 Chapter 1 BioChemistry Study Guide

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Chapter 1 ³Measurement´

1.1 Units of Measurement

Length

o Meter (m) ± slightly longer than a yard

1 m = 100 cm

1 m = 39.4 in.

o Centimeter (cm) ± smaller unit of length

and commonly used in chemistry

2.54 cm = 1 in.

Volume ± amount of space a substance

occupies

o Liter (L) ± slightly larger than the quart

and commonly used to measure volume

1 L = 1000 mL

1 L = 1.06 qt

o Milliliter (mL) ± more convenient for

measuring smaller volume of fluids in

hospital or lab

946 mL = 1 qt

Mass (weight) ± measure of the quantity of

material it contains

o Gram (g)

454 g = 1 lb

o Kilogram (kg)

1 kg = 1000 g

1 kg = 2.20 lb

Temperature ± how hot or cold that object is

(metric system measured on the Celsius

temperature scale but SI system measured on

the Kelvin (K) temperature scale

o Celsius (°C) scale ± water freezes at

0 °C and boils at 100 °C

o Fahrenheit (°F) scale ± water freezes at

32 °F and boils at 212 °F

o Kelvin (K) ± 0 K

Time

o Years

o Days

o Minutes

o Seconds

Table 1.1 ³Units of Measurement´

Measurement Metric SI

Length Meter (m) Meter (m)

Volume Liter (L) Cubic meter

(m3)

Mass Gram (g) Kilogram (kg)

Time Second (s) Second (s)

Temperature Celsius (°C) Kelvin (K)

1.2 Scientific Notation

Scientific notation ± easy way to write small and

large numbers

o Example

Width of a human hair is

0.000008 m, but in scientific

notation is 8 * 10-6

m

Writing a number in scientific notation:

o Two parts ±

A coefficient

Power of 10

o Example

2.4 * 103

Coefficient is 2.4

103

shows the power of 10

Table 1.2 ³Some Powers of 10´

Number Multiples of Ten Scientific

Notation

10000 10*10*10*10 1 * 104

1000 10*10*10 1 * 103

100 10*10 1 * 102

10 10 1 * 101

1 0 1 *100

0.1 1/10 1 * 10-1

0.01 1/10*1/10 = 1/100 1 * 10-2

0.001 1/10*1/10*1/10 =

1/1000

1 * 10-3

0.0001 1/10*1/10*1/10*1/10

= 1/10000

1 * 10-4

Scientific notation and calculators:

o Using the EE or EXP key on calculator



1.3 Measured Numbers and Significant Figures

Measured numbers ± number that I obtain from

using a measuring tool

o Example

Height

Weight

Temperature

Table 1.4 ³Significant Figures in Measured

Numbers´

Rule Measured

Number

Number of

Significant

Figures

A number is a

significant figure

if it is

(a) Not a

zero

4.5 g 2

122.35 m 5

(b) A zero

b/t

nonzero

digits

205 m 3

5.082 kg 4

(c) A zero at

the end

of a

decimal

number

50. L 2

25.0 °C 3

16.00 g 4

(d) Any digit

in the

coefficient of a

number

written in

scientific

notation

4.0 * 105

m 2

5.70 * 10-3

g 3

A zero is not

significant if it is

(a) At the

beginnin

g of a

decimal

number

0.0004 lb 1

0075 m 2

(b) Used as

a

placehol

der in a

large

number

without a

decimal

point

850000 m 2

1250000 g 3

Significant figures ± all the digits including the

estimated digit

Exact numbers ± numbers obtained by counting

items

o Example

1 ft = 12 in.

1 qt = 4 cups

1 lb = 16 ounces

1 L = 1000 mL

1 m = 100 cm

1 kg = 1000 g

1.4 Significant Figures in Calculations

Rounding off

o Rules for rounding off:

If the first digit to be

dropped is 4 or less, it and

all following digits are

simply dropped from the

number

If the first digit to be

dropped is 5 or greater, the

last retained digit of the

number is increased by 1

Example:



y 8.4234 rounds off to

8.42 or 8.4

y 14.780 rounds off to

14.8 or 15

Multiplication and division ± final answer is

written so it has the same number of

significant figures as the measurement with

the fewest significant figures (SFs)

o Example

24.65 * 0.67 = 16.5155 ± 17

Adding significant zeros ± significant zeros

may need to be written after the calculator

result

o Example

8.00 / 2.00 = 4 = 4.00

Addition and subtraction ± final answer iswritten so it has the same number of

decimal places as the measurement with the

fewest decimal places

o Example

2.045 + 34.1 = 36.145 =

36.1

1.5 Prefixes and equalities

Prefix ± attached to any unit to increase or

decrease its size by some factor of ten Prefixes that increase the size of the unit ±

o Tera = 1000000000000

o Giga = 1000000000

o Mega = 1000000

o Kilo = 1000

Prefixes that decrease the size of the unit ±

o Deci = 0.1

o Centi = 0.01

o Milli = 0.001

o Micro = 0.000001

o Nano = 0.000000001

o Pico = 0.000000000001

Measuring length

o Some length qualities:

1 m = 100 cm

1 m = 1000 mm

1 cm = 10 mm

Measuring volume

o Some volume equalities:

1 L = 10 dL

1 L = 1000 mL

1 dL = 100 mL

o Cubic centimeter (cm3)

1 cm3

= 1 cc = 1 mL

Measuring mass

o Some mass equalities:

1 kg = 1000 g

1 g = 1000 mg

1 mg = 1000 µg

1.6 Writing Conversion Factors

Conversion factors ± one of the quantities is

the numerator and the other is thedenominator

o Example

Numerator / Denominator

60 min / 1 h and 1 h / 60

min

Metric conversion factors

o Example

Metric equality (1 m = 100

cm) Conversion factors (100 cm

/ 1 m and 1 m / 100 cm)

Table 1.9 ³Some Common Equalities

Quantity U.S. Metric (SI) Metric (U.S)

Length

1 ft = 12 in. 1 km =

1000 m

2.54 cm = 1

in.

1 yard = 3 ft 1 m = 1000

mm

1 m = 39.4

in.

1 mile =

5280 ft

1 cm = 10

mm

1 km =

0.621 mi

Volume

1 qt = 4

cups

1 L = 1000

mL

946 mL = 1

qt

1 qt = 2 pt 1 dL = 100 1 L = 1.06



mL qt

1 gallon = 4

qt

1 mL = 1

cm3

Mass

1 lb = 16 oz 1 kg = 1000

g

1 kg = 2.20

lb

1 g = 1000mg

454 g = 1 lb

Time

1 h = 60

min

1 min = 60 s

Metric (U.S) system conversion factors

o Example

1 kg = 2.20 lb

Conversion factors

y 2.20 lb / 1 kg or 1 kg /

2.20 lb

Conversion factors stated within a problem

o Example

1 h = 85 km

Conversion factors

y 85 km / 1 h or 1 h / 85

km

Conversion factors for a percentage, ppm, and

ppb

o Example

18% body fat by mass = 100 kg

body mass

Conversion factors

y 100 kg body mass / 18

kg body fat or 18 kg

body fat / 100 kg body

mass

1.7 Problem Solving

Example

o Given quantity * one or more

conversion factors = desired

quantity

Guide to problem solving (GPS) using

conversion factors

o Given/Need

o Plan

o Equalities/Conversion Factors

o Set Up Problem

Using two or more conversion factors ± each

factor is arranged to cancel the preceding

unit until the final unit is obtained

1.8 Density

Density ± to determine an object will sink or

float

Formula

o Density = mass of substance /

volume of substance

Density of solids ± calculated from its mass

and volume

Specific gravity (sp gr) ± ratio between thedensity of a substance and the density of

water

Formula

o Specific gravity = density of sample

/ density of water

chapter 1 biochemistry study guide

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