Proteins 2 Flashcards Preview

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Flashcards in Proteins 2 Deck (15)
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1
Q

What are the 3 types of proteins?

A

Glycoproteins
Lipoproteins
Metalloproteins

2
Q

Define glycoproteins.

A

Any class of proteins which have carbohydrate groups attached to the polypeptide chain.

3
Q

Give 2 examples of glycoproteins.

A

Immunoglobulins

Blood group determinants

4
Q

What is glycosylation?

A

A process which occurs in the endoplasmic reticulum and golgi apparatus. It’s roles are: protein stabilisation, effect solubility, protein orientation, signalling and cell recognition.

5
Q

Define lipoproteins.

A

When proteins and lipids bond together and transport water and insoluble fats/cholesterol in the blood.

6
Q

Define good cholesterol.

A

High-density lipoprotein, transported back to the liver.

7
Q

Define bad cholesterol.

A

Low-density lipoprotein, get caught in arteries and can lead to heart attacks.

8
Q

Define metalloproteins.

A

Protein molecules with a bound metal ion, i.e haemoglobin. One third of proteins need a metal ion for their specific role.

9
Q

Haemoglobin is made up of…

A

2 alpha chains, 2 beta chains and an iron heme group.

10
Q

What is cooperative binding?

A

When the binding of a molecule to one subunit changes the affinity of the other subunits to the molecule.

11
Q

Define collagen.

A

Fibrous proteins which make up about 30% of the total proteins in humans. Strong and composed of repeated unit.

12
Q

How is collagen formed?

A

Polypeptides coil and form a helix and then 2 more join in to form a triple helix and are held together by hydrogen bonds. These can then form fibrils.

13
Q

What are LDL receptors?

A

Glycoproteins. They are present on the surface of all cells causing the internalisation of LDL.

14
Q

What are the 5 LDL receptor mutation effects?

A
No receptors produced
Receptors never reach cell surface
Receptors can't bind to LDL
Receptors don't internalise on binding to LDL
Receptors don't release LDL
15
Q

Define cryoglobulins.

A

Proteins which precipitate and solidify when the temperature gets less than 37 degrees celsius.