Quantities Flashcards
What is Avogadro’s number?
The number of molecules in one mole of a substance
How many molecules are in a mole of a substance?
6.022 x 10^23
How many molecules of NaCl in 10g?
- 10g NaCl/58.44g/mol = 0.171moles NaCl
- 0.171 moles NaCl x 6.022 x 10^23 =
1.03 x 10^23 molecules
How many molecules in 10µL of a 1M NaCl solution?
- 10µL = 10 x 10^-6L
- n = MV
- n = 1mol/L x 10 x 10^-6L = 1 x 10^-5 mol
- (1 x 10^-5 mol) x (6.022 x 10^23 molecules/mol) =
6.022 x 10^18 molecules
How many molecules in 44g of CO2?
- 44g CO2/44g/mol = 1 mole CO2
- 1 mole CO2 x 6.022 x 10^23 =
6.022 x 10^23 molecules
What is the average weight of an amino acid?
110 Da
What is the average weight of a dNTP?
327.0 Da
(single strand DNA)
What is a Dalton?
Atomic mass unit
What is the approximate weight of the following peptide:
M-A-R-S-H?
M = 149 Da
A = 89 Da
R = 174 Da
S = 105 Da
H = 155 Da
TOTAL = 672 Da
How many molecules of M-A-R-S-H in 1 pmol?
- 1pmol = 1 x 10^-12 moles
- Molecules = moles x Avogadro’s number
- (1 x 10^-12 moles) x (6.022 x 10^23 molecules/mole) =
6.022 x 10^11 molecules
What is the weight of 1 pmol of M-A-R-S-H?
- 1pmol = 1 x 10^-12 moles
- Weight (g) = Moles x Molar Mass (g/mol)
- (1 x 10^-12) x 672 g/mol =
6.72 x 10^-10 g
What is the approximate weight of the the following oligonucleotide?
A-A-A-C-C-C-G-G-G-T-T-T
(3 x 331.2) + (3 x 307.2) + (3 x 347.2) + (3 x 322.2) = 3923.4 Da (or g/mol)
How many molecules of A-A-A-C-C-C-G-G-G-T-T-T in 1 nmol?
- 1nmol = 1 x 10^-9 mol
- Molecules = moles x Avogadro’s number
- 1 x 10^-9mol x 6.022 x 10^23 = 6.022 x 10^14 molecules
What is the weight of 1 nmol of A-A-A-C-C-C-G-G-G-T-T-T?
- 1nmol = 1 x 10^-9 moles
- Weight (g) = Moles x Molar Mass (g/mol)
- (1 x 10^-9) x 3923.4 g/mol =
3.92 x 10^-6g
How would you make up 50ml of a 5M NaCl solution (MW NaCl = 58.44)?
- n = MV
- n = 5M x 0.05L = 0.25 mol
- Mass = moles x molar mass
- Mass = 0.25 mol x 58.44 g/mol = 14.61 g
- Add 14.61 g NaCl to 50ml solution
How would you make up a 100µM solution of the following oligonucleotide A-A-A-A-A-C-C-C-C-C-G-G-G-G-G-T-T-T-T-T if you were provided with 25 nmol of the oligo as a dried powder?
- 100µM = 1 x 10^-4M (mol/L)
- 25nmol = 2.5 x 10^-8 mol
- V = n/M
- V = (2.5 x 10^-8 mol) / (1 x 10^-4 mol/L) = 2.5 x 10^-4 L = 0.25ml
- Add 25 nmol dried powder to 0.25ml solution
How would you make up a 100µM solution of the following oligonucleotide A-A-A-A-A-C-C-C-C-C-G-G-G-G-G-T-T-T-T-T if you were provided with 10µg of the oligo as a dried powder?
- 100 µM = 1 x 10^-4M (mol/L)
- 10 µg = 1 x 10^-5 g
- (5 x 331.2) + (5 x 307.2) + (5 x 347.2) + (5 x 322.2) = 6539 Da (or g/mol)
- Moles = mass / molar mass
- Moles = (1 x 10^-5 g) / (6539 g/mol) = 1.53 x 10^-9 moles
- Volume = moles / concentration
- Volumes = 1.53 x 10^-9 moles / 1 x 10^-4 mol/L = 1.53 x 10^-5 L = 0.0153ml
- Add 10µg oligo to 0.0153ml solution
How many µm^3 in 1cm^3?
1 µm^3 = 1 x 10^-6 m^3
1 cm^3 = 1 x 10^-2 m^3
(1 x 10^-2)^3 m^3 / (1 x 10^-6)^3 m^3 =
1, 000, 000, 000, 000 µm^3 in 1 cm^3
How many nm^3 in 1cm^3?
1 nm^3 = 1 x 10^-9 m^3
1 cm^3 = 1 x 10^-2 m^3
(1 x 10^-2)^3 m^3 / (1 x 10^-9)^3 m^3 =
1 x 10^21 nm^3 in 1 cm^3
What is the approximate diameter of a human hair?
0.1 mm
What is the approximate diameter of a human cell?
10 - 100 µm
What is the approximate diameter of a bacterium?
0.5 µm
What is the approximate diameter of a virus?
10 - 100 nm
What is the approximate diameter of DNA?
10 nm
What is the approximate diameter of a protein?
1 - 100 nm
What is the approximate volume of an oocyte?
4,000,000 µm^3
What is the approximate volume of a fibroblast cell?
2,000 µm^3
What is the approximate volume of a red blood cell?
100 µm^3
What is the approximate volume of an E.coli?
1 µm^3
How many E.coli would fit in 1cm^3?
10^12
How many E.coli would you expect in 1ml of an overnight culture grown in a rich media?
10^9 to 10^10
How many E.coli would fit in a fibroblast?
2000
How many antibodies in IgM?
5
What is the approximate weight of an IgM molecule?
850 kDa
What exactly does it mean to say the affinity of a protein receptor for its ligand is 1 picomolar?
- Receptor has dissociation constant (Kd) of 10^-12 mol/L
- If a ligand is present at 10^-12 mol/L then 50% of receptors bound
Approximately how many protein molecules in a yeast cell?
42 million
How many proteins encoded by the yeast genome?
6,000
What is the abundance range of proteins in a yeast cell?
1000 - 10,000
About how many mRNA are there in a yeast cell?
60,000
What is the approximate weight of now human genome?
3.2 pg
Explain Dynamic Range
Dynamic range is the SIZE of the concentration range which a sensor or receptor can detect a molecule
Explain the Law of Mass Action
The rate at which a chemical reaction takes place is proportional to the product of the active masses of the reactants
Explain Kd
- Equilibrium Dissociation Constant
- When ligand concentration is equal to Kd, half of the receptors are occupied by a ligand at equilibrium
Explain the relationship between Kd and affinity
HIGHER the Kd, the LOWER the Affinity of receptor for ligand
