Plasma Proteins

Question 1

where are polar groups found on globular proteins

Answer 1

On the proteins surface

Question 2

Where are hydrophobic groups found in globular proteins

Answer 2

In the globular protein interior

Question 3

Fibrous vs Globular protein solubility

Answer 3

Folding in globular proteins increases solubility of proteins in water
Fibrous proteins are mainly insoluble structural proteins

Question 4

What structure do globular proteins have

Answer 4

Quaternary structure

Question 5

Hemoglobin structure

Answer 5

• 4 polypeptide chains: two alpha, 2 beta
• Held together by non covalent interactions
• Each chain has a heme group in center that carries oxygen
• Hb molecule has 4 heme groups and carries 4 O2 molecules

Question 6

Hb function

Answer 6

Carries O2 & CO2 to and from the lungs and tissues

Question 7

What does HbA undergo

Answer 7

Glycosylation (addition of glucose)

Question 8

Who are HbA1c levels high in

Answer 8

Patients with diabetes mellitus

Question 9

Function of albumin

Answer 9

Transports hormones, fatty acids, cholestrol through the blood

Question 10

Is albumin solube/insoluble

Answer 10

Soluble

Question 11

What is albumin synthesised as

Answer 11

As a pre-proprotein

Question 12

Low blood albumin levels caused by (6)

Answer 12

1. Liver disease: cirrhosis most common
2. Excess excretion by the kidneys: as in nephrotic syndrome
3. Burns: plasma loss in absence of skin barrier
4. Redistribution
5. Acute disease states
6. Mutation causing albuminemia (v/ rare)

Question 13

High blood albumin levels caused by (3)

Answer 13

1. Severe/chronic dehydration
2. Retinol (vit A) deficiency
3. High protein diets

Question 14

APRs concentration changes in… (4)

Answer 14

1. Infection
2. Surgery
3. Injury
4. Cancer

Question 15

Examples of positive APRs

Answer 15

• C-reactive protein
• Fibrinogen
• alpha 1 antitrypsin

Question 16

Examples of negative APRs

Answer 16

• Albumin
• Transferrin
• Antithrombin

Question 17

Globulins vs albumins

Answer 17

Globulins have a higher molecular weight & water solubility than albumins

Question 18

What are globulin made of

Answer 18

Different proteins called alpha, beta and gamma types

Question 19

Function of globulins

Answer 19

Bind with Hb to transport metals (e.g.: iron) in the blood & fight infection

Question 20

What are high globulin levels caused by (10)

Answer 20

1. Chronic inflammatory diseases (TB)
2. Bone marrow disorders (multiple myeloma)
3. Leukemias
4. Autoimmunity (collagen diseases)
5. Rheumatoid arthritis
6. Liver disease
7. Carcinoid syndrome
8. Ulcerative colitis
9. Kidney disease (nephrosis)
10. Chronic infections

Question 21

Low globulin levels are caused by (7)

Answer 21

1. Hepatic dysfunction
2. Celiac disease
3. Inflammatory bowel disease
4. Acute haemolytic anaemia
5. Proteins not digested and and absorbed properly
6. Hypogammaglobulinemia
7. Renal disease (kidneys dont filter protein from blood and it leaks into urine)

Question 22

What is transferrin

Answer 22

beta globulin

Question 23

Fuction of transferrin

Answer 23

Binds free iron in serum

Question 24

What causes decreased transferrin levels

Answer 24

1. Liver disease (cirrhosis)
2. Chronic infections
3. Nephrosis
4. Congenitalatransferrinaemia

Question 25

What are immunoglobulins

Answer 25

Antibodies produced by B cells in response to antigen stimulation of the organism

Question 26

Immunoglobulin structure

Answer 26

• Minimum 4 polypeptide chains
• 2 heavy chains and 2 light chains linked by disulphide bridges
• Light chains contain the constant and variable region