Bio Lab practical questions

Lab basics

kilo (k) factor

base unit factor

centi factor

milli factor

micro factor

1000

1

0.01

0.001

0.000001

submultiple are

multiples are

smaller than the base

bigger than the base

Milli

a submultiple 1000 times smaller than the base unit

Micro-

a submultiple one million times smaller than the base unit

Centi-

a submultiple 100 times smaller than the base unit

Kilo-

a multiple 1000 times larger than the base unit

What is the total magnification of a microscope with 20x ocular lenses and a 30x objective lens

600

What happens to the field diameter as magnification increases?

The field diameter gets smaller.

(the less of the specimen you can see)

You know that the field diameter of a scope using a 10x objective lens is 20 mm. What is the field diameter of a 40x lens in mm? Do not include units in your answer

5

Field diameter= FD1 x Mag1 = FD2 x Mag2

Due to the short working distance, the high magnification objective lens is the one most likely to contact a slide, potentially breaking the slide and damaging the lens

True

Which objective lens should be used to initially get a specimen in focus under the microscope?

4x (lowest one)

Why should you only use the fine focus when trying to put a specimen in sharp focus when using the 40x objective lens?

because the working distance is too small, and the coarse focus moves the stage too quickly.

Name

A = Flask

B = Graduated cylinder

C = Beaker

D = Test Tube

Name

A = Centrifuge tube (50mL)

B = PCR tube

C = microcentrifuge tube

D = centrifuge tube (15mL)

Total mag formula

objective mag x ocular mag = total mag

As magnification increases, field diameter becomes _______.

smaller

How many mL are in 4.6 L?

big to small = mulit

4600

How many mg are in 63.6 g

big to small = multi

63600 (x1000)

Convert 899 µg to mg

small to big = divide

0.899 (/1000)

Convert 62 µL to mL

small to big (divide)

0.062 (/1000)

Convert 81 L to mL

big to small (mulit)

81000 (x1000)

Convert 6 L to µL

L to mL to uL

big to small (mulit)

6000000 (x1000ml x1000 ul)

Name

A = beaker

B = graduated cylinder

C = erlenmeyer flask

D = test tube

microgram

ug

small to large = dividing so you move deci to ___

large to small = multiplying so you move deci to ___

left

right

nm to mm

divide by 10^6 (6 becomes pos because moved to denomonator)

m to um

multiply (10^6 6 stays pos because you are multiplying which is in the numorator)

kg to cg

multiply (times by 10² stays pos 2 bc multiplying happens in numorator)

unknown field diameter

(known FD) x (initial FD) / final Mag

Molarity

mol/L

MW

g/mol

initial con. x volume initial = final con. x volume final

C1 x V1 = C2 = V2

in this formula units MUST MATCH

make 5ml of 10 mM NaCl from 50 um stock

1.0 uL of 50 um

mL to uL

x 1000

can a hypothesis be phrased as a question

no

Independent variable vs Dependent variable

IV : the thing you manipulate or change

DV; what changes bc of the IV

What button is used to subtract the mass of the weighing vessel from the display on a digital scale?

Tare

solute vs solvent

Solute: the substance being dissolved in a solution

Solvent: the liquid in greater quality (where the solute is being dissolved in)

How many grams of KOH are needed to make 1 liter of a 1 M KOH solution? FW KOH = 56.11 g/mol.

1

How many moles are in 1 L of a 2 M KOH solution? (FW KOH = 56.11 g/mol

2

How many moles are in 0.1 L of a 2 M KOH solution? (FW KOH = 56.11 g/mol)

0.2

How many grams of CaCO₃ are needed to prepare 2 L of a 6 M CaCO₃ solution (FW of CaCO₃ = 100.09 g/mol). Do not include units in your answer. Report your answer to the nearest two decimal places

1201.08

How many grams of NaCl are needed to prepare 1200 mL of a 2 M NaCl solution (FW of NaCl = 58.44 g/mol). Do not include units in your answer. Report your answer to the nearest two decimal places

140.26

Which is the best instrument to move 4 mL of water?

5mL serological pipette

best instrument for

100uL

300uL

1.5mL

7mL

P200 micropipette

P1000 micropipette

2mL serological pipette

10mL serological pipette

What is the purpose of the "first stop" when using a micropipette?

This is the appropriate starting position for drawing liquid up into the pipette

Name

A) plunger

B) volume Adjustment dial

C) Tip ejector button

D) volume display

E) volume range

How many grams of NaCl are needed to prepare 40 mL of a 2 M NaCl solution? (FW NaCl = 58.44 g/mol)

4.675

What's the difference between the tare and zero function on the balance? Describe a situation in which it would be beneficial to use the tare function over the zero function.

The zero button is used when there is nothing on the scale and you just want to calibrate the scale. However, the tare button is used to cancel out the weight of the object that is on the scale. It would be beneficial to use the tare button over the zero button if you are weighing a new mass in a beaker that already has liquid in it.

How much

36.5

Density formula

D = Mass/Volume

Chemistry

What must you make sure to always do when moving the probe between solutions

rinse the bottom third of probe w/ dH2O

How many grams of sucrose (FW = 342.3 g/mol) are needed to make 40 mL of a 0.2 M sucrose solution?

2.7384

How many mL of 1 mM BSA stock solution do you need to make 40 mL of an 0.2 mM BSA working solution

8

How can you tell that disodium phosphate (Na₂HPO₄) is the conjugate base and monosodium phosphate (NaH₂PO₄) is the weak acid

Disodium phosphate has one less hydrogen atom than monosodium phosphate

How many mL of the 100 mM NaH₂PO₄ stock solution will you need to make 40 mL of a 1.8 mM NaH₂PO₄ working solution

0.72

V= mL x mM / mM

Biological molecules

Glucose =

lactose =

starch =

maltose =

galactose =

glycogen =

glucose =

cellulose =

sucrose =

monosaccaride

disaccharide

polysaccharide

disaccharide

monosaccharide

polysaccharide

monosaccharide

polysaccharide

disaccharide

Enzymes

Both catalysts and enzymes work by lowering the activation energy needed to start a reaction.

true

A biological molecule that increases the rate of a reaction is most likely...

an enzyme

enzymes are ____

proteins

an enzyme is not used up in the reaction it catalyzes

true

This part of the enzyme binds to the substrate.

active site

True/False: A protein that has lost its three-dimensional structure due to low pH would still function as an enzyme.

False

A phosphatase enzyme will...

remove a phosphate group from a molecule.

Hue reflected is the one ____

seen by use

lipids =

nucleic acids =

proteins =

starch =

lipase

nuclease

pepsin

amylase

amylase produces

maltose

Lipase produces which product(s)?

glycerol and fatty acids

Pepsin produces which product(s)?

amino acids and peptides

How many essential amino acids are there?

9

Salivary amylase is an enzyme that begins breaking down carbohydrates while the food is still in the mouth. Once the food passes into the stomach, what happens to the salivary amylase?

It is inactivated by the acidic conditions of the stomach.

Which biological macromolecule(s) is/are chemically digested in the duodenum?

carbohydrates, lipids, and proteins

proper way to load a centrifuge tube into the rotor

hinges out

What type of tissue

simple columnar epithelium

esophagus

salivary gland

cecum

stomach

duodenum

pancrease

Name

A) esophagus

B) liver

C) pancreas

D) duodenum

E) stomach

F) gallbladder

A) jejunum

B) duodenum

C) descending colon

D) cecum

E) ileum

F) rectum

Membranes

True or False: Osmosis is a an active process that requires ATP.

F

Osmosis

the diffusion of water across a membrane.

The osmolarity of a cell is 0.3 Osm. Which solution of NaCl is isosmotic to the cell?

0.15

A cell is placed into a solution of pure water. What is the tonicity of the water solution?

hypotonic

Placing an animal cell into a hypertonic solution will result in...

crenation

A synthetic "cell" is made out of semi-permeable dialysis tubing, and it contains a 10% sucrose solution. It is placed into a beaker containing a 20% sucrose solution. The solution in the beaker is...

hypertonic

Imagine another scenario. This time, a cell is placed in a solution of NaCl that is more concentrated than the cytosol inside the cell. NaCl and its ions are not able to cross the cell membrane. What will happen?

Water will flow out of the cell.

How many grams of maltose do you need to make 550 mL of a 13 % w/v solution?

71.5

How many mL of acetone do you need to make 450 mL of a 8% v/v solution?

36

How many grams of NaOH do you need to make 750 mL of a 8% w/v solution?

60

How many mL of ethanol do you need to make 150 mL of a 65% v/v solution?

97.5

abdominal aorta

inferior vena cava