Biochem Lab Final

Metric System

Set of standard units defined to measure length, weight, capacity (volume) It is based on the decimal system as it includes numbers in powers of 10.

Metric Units

1Liter (L)	1000 milli liter (mL)
1 mL	1000 micro-liter (µL)
1Gram(g)	1000 milli grams (mg)
1 mg	1000 micro-grams

Metric Conversion

Solution

A homogeneous mixture (components are uniformly distributed) composed of two or more substances

Solute

A substance dissolved in another substance

Solvent

A substance that dissolves a solute

Concentration

A measure of the amount of solute that has been dissolved in a specified amount of solvent or solution

Lab 1 Calculations

• Solute(gr) = M.W.(Molecular Weight) M(Molar) * V(Liter)

• Molarity (M) = Moles of solute/Liters of solution

• Molarity = Mass of the solute/(Molar mass of the solute)(Vol. of soln. in liters)

Molarity

A measure of how much of a substance is dissolved in a solution

Micropipettors

• Accurate, precise, and rapid dispensing of volumes

• From 1-10,000µL

• The “0” is the decimal point

Precision

Extent of agreement among repeated measurement

Accuracy

Difference between experimental value and expected (true) value

Standard Deviation (S.D.)

• How widely spread or dispersed the values in a data set are from the average or expected value

• A low standard deviation means that most of the numbers are close to the expected value. A high standard deviation means that the numbers are more spread out

Percent Error

% Error = (measured - true value)/true value * 100

Lab 1 Experiment

Strong Acid

A compound containing a hydrogen ion that it can give up to the solution (dissociation is complete)

Strong Base

A compound that yields a hydroxyl ion when  dissolved in water (dissociation is complete)

Weak Acids

Don’t dissociate completely in water

Assessing Acid Strength

• Equilibrium constant or dissociation constant

• Tendency to lose protons/hydrogen ions

Titration

A technique to determine the concentration of an unknown solution

Equivalence Point

At the equivalence point in an acid-base titration, moles of base = moles of acid and the solution only contains salt and water

Buffers

Solutions containing a weak acid and its conjugated base are capable of resisting changes in pH upon addition of small amount of acid or base

Henderson-Hasselbach Equation

Lab 2 Experiment