proteins

Question 1

crude extract

Answer 1

breaking tissues or cells by lysis or homogenization

Question 2

sub cellular ractionation

Answer 2

remove/isolate specific
organelles by centrifugation/filtering

Question 3

separation of protein fractions

Answer 3

remove/enrich specific
proteins by ‘salting out’-precipitation (use the solubility of
the protein) and by further refined method

Question 4

separation of protein properties

Answer 4

• Charge: pI of the protein vs pH and salt concentration of the
  solution
• Size: molecular mass and shape of the protein
• Affinity for a ligand (enzyme substrate, antibody, etc)
• Solubility
• Hydrophobicity
• Thermal stability

Question 5

electrophoresis

Answer 5

• Electric field pulls proteins according to their charge
• Gel matrix hinders mobility of proteins according to their size and
  shape

Question 6

2D electrophoresis

Answer 6

Combine isoelectric focusing and SDS electrophoresis (charge and size)

Question 7

isoelectric focusing

Answer 7

Separates proteins according to their isoelectric point (pI) and can be used
to determine the pI of a protein
Separation on charge
Each protein will migrate
until it reaches a pH=pI

Question 8

total activity

Answer 8

total enzyme units

Question 9

specific activity

Answer 9

number of enzyme units per milligram of total protein, increased by pruification

Question 10

immunoblotting (western blotting)

Answer 10

specific antibodies target specific proteins, detection depends on chemistry linked in secondary antibody

Question 11

mass spectrometry

Answer 11

*Basic principle of mass spectrometry
➢measure mass (m) to charge (z) ratio
*Analyse protein sequence (protein sequencing)
*Analyse protein modifications