MIDTERM LEC: PROTEINS

Question 1

The word PROTEINS come from the Greek word ____ which means “first rank of importance”

Answer 1

“proteis”

Question 2

Most proteins are synthesized in the liver except:

Answer 2

immunoglobulins, adult hgb, factor VIII

Question 3

High molecular weight composed of amino
acid - combined together by peptide bonds

Answer 3

PROTEINS

Question 3

Also called macromolecule

Answer 3

PROTEINS

Question 4

best quantified by immunologic measurements since it is below the level of detection by electrophoresis Clinical

Answer 4

PROTEINS

Question 5

● Marker for nutritional status
● Confirms if specimen is CSF

Answer 5

PROTEINS

Question 6

are amphoteric which means that they are able to react both as a base and as an acid

Answer 6

PROTEINS

Question 7

Simplest form of protein

Answer 7

amino acid

Question 7

produced in the Liver

Answer 7

fetal hemoglobin

Question 8

produced in Bone Marrow

Answer 8

adult hgb

Question 9

produce in Endothelial Cells, part of Coagulation Cascade

Answer 9

factor VIII

Question 10

Biological function of proteins:

Answer 10

● Structural support for the tissue (collagen
and keratin)
● Contraction and relaxation of muscles
● Coagulation and immunologic function
● Transport of metabolic substances [esp
cannot travel blood alone]
● pH buffer
● Precursor of hormones [Most of the
hormones are made up of proteins]
● Maintenance of osmotic pressure
● Biochemical catalysts [All enzymes are
Proteins]

Question 11

– for smaller polypeptides

Answer 11

Pepsin (enzyme)

Question 12

protein denaturation

Answer 12

HCI

Question 13

convert trypsinogen to
trypsin

Answer 13

Enteropeptidase

Question 14

cleaves peptide bonds

Answer 14

Chymotrypsin

Question 14

Total Protein – Albumin =

Answer 14

Globulin

Question 15

linear sequence of amino acids

Answer 15

Primary Structure

Question 16

it determines the identity of protein,
molecular structure, function and binding
capacity

Answer 16

Primary Structure

Question 17

refers to specific regular three-dimensional
formations into which portions of the
polypeptide chain fold [a-helix & B-pleated
sheet]

Answer 17

Secondary Structure

Question 18

actual 3-dimentional structure or folding pattern

Answer 18

Quaternary Structure

Question 18

responsible for physical and
chemical properties of proteins

Answer 18

Tertiary Structure

Question 19

may consists of single or more
polypeptide

Answer 19

Proteins

Question 20

a large number of amino
acids join together

Answer 20

Polypeptide

Question 21

2-20 of Amino acids

Answer 21

Oligopeptide

Question 22

contain peptide chains which on hydrolysis will yield only amino acids

Answer 22

Simple Proteins

Question 22

Amino acids are linked by peptide bonds

Answer 22

Peptide

Question 23

- contain protein and non-protein group - Ex. Metalloproteins, lipoproteins, glycoproteins, nucleoproteins, mucoprotein [Lipoproteins – protein molecule with lipid]

Answer 23

Conjugated Proteins

Question 24

transport protein bound to thyroxine (T4) and Retinol (Vit A)

Answer 24

Prealbumin/Transthyretin

Question 24

best quantified by immunologic measurements since it is below the level of detection by electrophoresis

Answer 24

Prealbumin/Transthyretin

Question 25

Clinical Significance: - Marker for nutritional status - Confirms if specimen is CSF - [Albumin is still abundant in CSF, Pre-albumin also but few]

Answer 25

Prealbumin/Transthyretin

Question 26

Most abundant protein generally used for transport [starts in fetal life to death] [50%]

Answer 26

Albumin

Question 27

Maintains fluid balance in tissues [contributes in oncotic pressure 80%]

Answer 27

Albumin

Question 28

Clinical Significance: ● negative acute phase reactant

Answer 28

Albumin

Question 29

are substances that are related to inflammation

Answer 29

acute phase reactant

Question 29

decreased levels: malnutrition, malabsorption, liver disease, renal disease, skin loss, dilution

Answer 29

Albumin

Question 30

level decreases in cases of inflammation

Answer 30

negative acute phase reactant

Question 31

value of the substance increase in cases of inflammation

Answer 31

positive acute phase reactant/APR

Question 32

not an actual disease state,🡩 albumin levels in the blood, it doesn’t mean a Disease, it can be an artifact (venous stasis, over infusion in IV, dehydration (most common)] [Protein production is Constant = there is no Increased synthesis Albumin

Answer 32

Hyperalbuminemia

Question 33

will tell a problem/disease state

Answer 33

Hypoalbuminemia

Question 34

Globulins

Answer 34

Alpha1, alpha2, beta and gamma fractions [dependent in electrophoretic mobility & migration]

Question 35

inactivate proteases [trypsin & neutrophil elastase] [releases WBCs to fight infxn but can attack normal tse esp. Lungs, will lead to Emphysema]

Answer 35

α-1 antitrypsin/anti-proteinase

Question 35

major component of α-1 globulins

Answer 35

α-1 antitrypsin/anti-proteinase

Question 36

Clinical Significance: ▪ acute phase reactant ▪ deficiency: pulmonary emphysema, hepatic cirrhosis [emphysema -chronic obstructive pulmonary dse] [hepatic cirrhosis due to genetic mutations abnormal proteins form aggregates cannot secreted in the Liver causing liver damage]

Answer 36

α-1 antitrypsin/anti-proteinase

Question 37

# * cleave pancreatic elastase

Answer 37

α-1 antichymotrypsin

Question 38

serine proteinase inhibitor

Answer 38

α-1 antichymotrypsin

Question 39

Clinical Significance: ▪ acute phase reactant ▪ associated with: Alzheimer disease and Parkinson’s disease [problem in the Liver most likely affected production proteins

Answer 39

α-1 antichymotrypsin

Question 40

o protects fetus from immunologic attack by the mother o levels decreases gradually after birth

Answer 40

α-1 fetoprotein

Question 41

Clinical Significance: ▪ increased levels: Spina Bifida, Neural Tube Defects, Anencephaly ▪ decreased levels: Down Syndrome and Trisomy 18

Answer 41

α-1 fetoprotein

Question 42

α-1 fetoprotein tumor marker:

Answer 42

hepatocellular CA

Question 43

undetected during adulthood, if detectable/🡩 α1 fetoprotein it will show presences tumor esp. Hepatocellular Carcinoma

Answer 43

α-1 fetoprotein

Question 44

only protein that is negatively charged even in acidic state [presence salicylic acid]

Answer 44

α-1 glycoprotein /orosomucoid

Question 45

Clinical Significance: ▪ Acute phase reactant ▪ increased levels: stress, Carcinoma, Rheumatoid Arthritis, inflammation, Acute Myocardial Infection, pregnancy, pneumonia, surgery

Answer 45

α-1 glycoprotein /orosomucoid

Question 46

largest major non-immunoglobulin

Answer 46

α-2 macroglobulin

Question 47

inactivate proteases

Answer 47

α-2 macroglobulin

Question 48

Clinical Significance: ▪ increased levels: nephrotic syndrome [> albumin concentration] [nephrotic syndrome filters protein too large in the kidney, problem in Glomerulus membrane is destroyed]

Answer 48

α-2 macroglobulin

Question 49

transports cholesterol, triglycerides and phospholipids

Answer 49

Lipoprotein

Answer 50

Ceruloplasmin

Question 51

Clinical Significance: ▪ Acute phase reactant ▪ increased levels: Menke’s Kinky Hair Syndrome ▪ decreased levels: Wilson’s disease, malnutrition, malabsorption [Wilson’s disease (hallmark: Keiser Fletcher Rings) – 🡩 levels copper in the body, most of Ceruloplasmin will be bound to the 🡩 levels of copper]

Answer 51

Ceruloplasmin