C11 Amino Acids & Proteins Flashcards Preview

Clinical Chemistry > C11 Amino Acids & Proteins > Flashcards

Flashcards in C11 Amino Acids & Proteins Deck (70):
1

Proteins

single most important group of organic compounds associated with living organisms

2

Lipids

water insoluble fatty molecules- require proteins in order to be transported through the plasma...lipoproteins

3

Amino acids

building blocks of proteins

4

DNA

very large molecule that contains biochemical codes to make proteins from amino acids

5

Genomics

study of DNA

6

Genome

all the DNA in a living organism

7

Nucleotides

2 purine bases (adenine and guanine)
2 pyrimidine bases (cytosine & thymine)

8

Adenine bonds with?

Thymine

9

Guanine bonds with?

Cytosine

10

Three groups of consecutive bases that provide the code for an amino acid?

codon

11

Sequence of DNA that provides the code for an entire protein?

Gene

12

When cells divide, the DNA condenses in visible structures called?

chromosomes

13

Each nucleated cell has 23 pairs of chromosomes, each representing a pair of DNA molecules which are joined at a central?

centromere

14

Human DNA contains how many genes?

20-25,000

15

DNA provides a code for the creation of?

mRNA

16

How is mRNA created?

actions of RNA polymerase and a promoter protein (Transcription)

17

What is translation?

When mRNA goes into the ribosomes where it meets up with individual amino acids and assembles them together to create proteins

18

What are DNA or NAT probes?

lab techniques that allow for the detection of specific nucleotide sequences

19

Advantages of DNA probes and NAT?

extremely specific, sensitive, and faster than routine culture

20

Disadvantages of DNA probes and NAT?

extreme sensitivity can cause problems if contaminated with outside sources, difficult and expensive techniques

21

All proteins are composed of?

amino acids

22

How many naturally occurring amino acids are there?

20

23

Aminoacidopathies?

uncommon, inherited, genetic disorders of amino acid metabolism

24

Most common aminoacidopathy?

Phenylketonuria (PKU)

25

Phenylketonuria

autosomal recessive (requires 2 defective genes from both parents), absence of phenylalanine hydroxylase... si cannot be converted to tyrosine, it accumulates and is converted to phenylpyruvic acid (which is toxic to newborns and kids resulting in brain damage and mental retardation) damage begins 2-3 wks after birth, treated with dietary restrictions

26

Guthrie Test

Small disk of filter (PKU) paper is punched out and placed on agar plate containing Bacillus subtillis & B2 thienylalanine, the agar gel is able support bacterial growth but B2 thienylalanine inhibits it, though with extra phenylalanine bacteria can grow, growth is proportional to amount of phenylalanine in serum

27

Primary (Protein conformation)

amino acid sequence

28

Secondary (protein conformation)

winding, twisting of the amino acid chain, regulated by hydrogen bonding between different locations on the chain

29

Tertiary (protein conformation)

3D structure of the amino acid chain, regulated by chemical interactions between the "R" groups

30

Quaternary (protein conformation)

non-covalent bonding between 2 or more polypeptide chains

31

Amino acids are linked together by a special type of chemical bond called?

peptide bond

32

A peptide bond occurs between a __ and a ___ of another?

carboxyl group of one amino acid, amino group

33

Whenever 2 amino acids are linked together with a peptide bond, what molecule is produced?

water

34

amphoteric

may have a + or - electric charge

35

Most proteins are synthesized in?

the liver

36

Immunoglobulins are synthesized in?

B-lymphs

37

3 sources of amino acids?

digestion and absorption, synthesis by liver, and re-utilization from protein catabolism

38

How many of the 20 amino acids can be synthesized by the liver and how many must be ingested?

11 are synthesized, 9 must be ingested

39

Peptide chains composed only of amino acids?

simple proteins

40

composed of a protein fraction and a non protein fraction?

conjugated proteins

41

lipoproteins

protein+lipid

42

glycoprotein

protein+carbohydrate

43

nucleoprotein

protein+nucleic acids

44

General functions of proteins:

energy source, contribute to osmotic pressure, act as buffers, transport molecules, coagulation/hemostasis, immune function, hormones and hormone receptors, structural molecules

45

Prealbumin

migrates ahead of albumin, decreased amt indicated poor nutrition, 15-40 mg/dl

46

Albumin

highest concentration of proteins, 80% of tissue osmotic pressure, major transport and binding protein, decreased amt associated with poor nutrition, liver, and renal disease

47

Alpha-1-Anti-Trypsin

Migrates in Alpha1 band, acute phase reactant, decreased amt associated with pulmonary disease

48

Alpha-1-Fetoprotein

Migrates between alpha1 and albumin band, synthesized in yolk sac and liver during gestation decreases after birth, increased: spina bifida, neural tube defects, twins, hepatocellular cancer, decreased: down syndrome and trisomy 18

49

Haptoglobin

Alpha 2, binds free hemoglobin, preventing loss in urine,, increased: inflammatory conditions, decreased: intravascular hemolysis

50

Transferrin

Beta, iron transport protein, increased with iron deficiency, decreased with anemia

51

Hemopexin

beta, acute phase reactant, bind free heme and transports it to liver

52

Complement

activated can lyse cells, C3 and C4 most abundant, increased in acute inflammatory conditions, decreased in chronic autoimmune disorders (RA and LE)

53

C-Reactive Protein (CRP)

Gamma, increased in infection, gout, autoimmune disease, cancers, tissue necrosis, early indicator for CVD and Type 2 diabetes

54

hs-CRP (high sensitivity)

high CRP in lower survival post AMI and arterial re-closure post balloon angioplasty,

55

Immunoglobulins

gamma, each antibody has 2 heavy & 2 light chains, antibody specificity determined by variable region at end of heavy & light chains, light chains are kappy lambda, multiple myeloma produces large concentrations of a single class of IgG, Waldenstrom's disease produces IgM

56

IgG

increased in chronic infections

57

IgM

increased with acute infections

58

IgE

associated with parasitic infections & allergic immune reactions

59

IgA

found in secretions

60

Myoglobin

heme protein found in skeletal & cardiac muscle, AMI, elevated 1-3hrs post AMI, peaks at 5-12hrs post AMI, returns to normal by 18-30hrs, also elevated in crush injuries & renal failure 30-90ng/ml

61

Troponin

complex of 3 proteins that regulate muscle contraction in cardiac & skeletal muscle, associated with cardiac tissue & is useful to evaluate possible AMIs, elevated 3-4hrs post AMI, peaks 10-24hrs post AMI, remains elevated 10-14 days, single best test for the diagnosis of AMI <.06ng/ml

62

B-Type Natriuretic Peptide (BNP)

hormone the heart releases in response to increased heart pressure associated with CHF, increased BNP causes arterial and venous vasodilation, suppression of aldosterone and promotes diuresis (decreases bp) 0-100pg/ml

63

Actue Phase Proteins (Reactants)

Positive-increased concentration during inflammation
Negative-decreased concentration during inflammation

64

Hypoprotenemia

below normal TP indicates a negative nitrogen balance, decreased protein synthesis, increased protein loss

65

Hyperprotenemia

excessive protein synthesis, dehydration

66

Kjedahl Method for Total Protein

classic reference method used to standardize all other techniques (technically difficult, labor intensive, and expensive) based upon measurement of total nitrogen and the following relationship between nitrogen and protein (16%)(Total Nitrogen)=(Total Protein)
No longer done routinely!

67

Biuret Method for Total Protein

**** most common technique, all proteins have peptide bonds, cupric ions react with peptide bonds to produce a violet color that is measured at 540 nm

68

Dry binding technique

most protein will bind with various dyes to produce colored complexes, downside is that different proteins have different affinities for different dyes resulting in variable results

69

Albumin determination

measured by Brom Cresol Green (BCG) and Brom Cresol Purple (BCP)

70

Refractometer

protein (and other substances) in solution refract light rays as they pass through the solution