Unit 2 - Types Of Proteins Flashcards
Are globular proteins water insoluble or soluble?
Globular proteins are water soluble
Insulin is a —- protein
Globular
Why do hormones need to be water soluble?
So they can travel in the blood stream, as hormones do
Why do hormones have to be specific shapes?
Have to fit into specific receptors on the cell surface membrane
What is a conjugated protein?
Globular proteins that contain a non-protein component
What is a non protein component called
Prosthetic group
What are proteins without a prosthetic group known as?
Simple proteins
Examples of prosthetic groups
Glycoproteins, lipoproteins
In each haemoglobin 4 subunits, there is..?
a prosthetic haem group, from fe 2+ ions
How is haemoglobin able to carry oxygen?
The fe 2+ ions in the haemoglobins subunits (4x) are able to combine reversibly with an oxygen molecule
What does catalase have 4 of?
Haem prosthetic groups
What do the haem prosthetic groups in catalase enzyme allow it to do?
Can interact with hydrogen peroxide and speed up its breaking down, which is useful as it is damaging to cells
What is a common byproduct of metabolism
Hydrogen peroxide, harmful if accumulates in cells
Fibrous proteins are formed from
Long, insoluble molecules
How are fibrous proteins so long
High proportion of amino acids with hydrophobic r groups, in primary structures
The amino acid sequence in fibrous proteins is
Limited range, small r groups, quite repetitive
What does the repetition of amino acids mean in a fibrous protein
Very organised structure
Examples of fibrous proteins
Keratin, elastin, collagen
Which protein is NOT folded into a complex, 3D shape?
Fibrous, globular are!
What amino acid does keratin have a lot of?
High sulfur contented cysteine!
What determines the flexibility of a fibrous protein
Amount of disulfide bridges - hair has less than nails, which are more brittle
Cysteine amino acid, very frequent in keratin that has lots of sulfur
Where is the fibrous protein elastin found?
The walls of blood vessels, alveoli in lungs
Enable to stretch when needed, and return back to normal shape
Elastin has a _____ protein
Quaternary, made of many stretchy molecules called tropoelastin
What is elastin made of
Tropoelastin
Where is collagen found
Connective tissue, (skin, tendons, ligaments, nervous system)
