globular proteins 1, haemoglobin

what two groups do scientists divide proteins into?

• globular proteins

• fibrous proteins

what are the three globular proteins?

• haemoglobin

• enzymes

• insulin

what shape are globular proteins?

spherical

why are globular proteins soluble in water??

they have hydrophilic amino acids on their surface so the hydrophilic r groups can interact with water

where are hydrophobic amino acids found in globular proteins?

deep in the centre of the protein far away from water

how many polypeptide subunits does haemoglobin contain?

4

what are the names of the 4 subunits found in haemoglobin?

two called alpha subunits, two called beta subunits

where is haemoglobin found?

in red blood cells

what is the function of haemoglobin?

to bind to oxygen

what does each subunit of haemoglobin contain?

the prosthetic group haem

what type of protein is haemoglobin?

a conjugated protein

what ion does each haem group contain?

an Fe 2+ ion where the oxygen binds

how many oxygen molecules can bind to one haemoglobin molecule bind to?

4 oxygen molecules

what changes when oxygen attaches to haemoglobin making what easier?

the quaternary structure of the protein slightly changes making it easier for oxygen to attach