Biochemistry Exam 3 Flashcards
Basic structure of an amino acid contains what 2 functional groups?
Amine and carboxylic acid
What are amines derived from?
Ammonia (NH3)
What is carboxylic acid derived from?
Carbon double bonded to oxygen and single bonded to a hydroxyl group
Short chains of amino acids (2~50) held together by peptide bonds
Peptides
Chain of 2 amino acids
Dipeptides
Longer chains of amino acids (>50)
Polypeptides
Large chains of polypeptides (200-300 typically) are known as
Proteins
Why are certain amino acids “essential”?
The body cannot synthesize them so we have to get them from our diet
What are the essential amino acids? (10)
PVT TIM HALL
Phenylalanine (Phe)
Valine (Val)
Threonine (Thr)
Tryptophan (Trp)
Isoleucine (Ile)
Methionine (Met)
Histidine (His)
Arginine (Arg)
Leucine (Leu)
Lysine (Lys)
What are the nonessential amino acids?
Alanine (Ala)
Asparagine (Asn)
Aspartic acid (Asp)
Cysteine (Cys)
Glutamic acid (Glu)
Glutamine (Gln)
Glycine (Gly)
Proline (Pro)
Serine (Ser)
Tyrosine (Tyr)
What are the 2 recently identified amino acids?
Selenocysteine (Sec)
Pyrrolysine (Pyl)
Inherited enzyme defects which inhibit metabolism of certain amino acids
Amino-acidopathies
Where are proteins primarily synthesized?
The liver
What proteins are not synthesized in the liver? Where are these synthesized?
Immunoglobulins/antibodies
They are synthesized in plasma cells
What are the 4 levels of protein structure?
Primary, Secondary, Tertiary, and Quarternary
If pH > pI, what is the protein’s net charge?
Negative
If pH < pI, what is the protein’s net charge?
Positive
What are simple proteins composed of?
Peptide chains of only amino acids
What simple protein shapes serve as transporters, enzymes, and messengers?
Globular simple proteins
What simple protein shape provides structure to cells?
Fibrous simple proteins
What makes up conjugated proteins?
A protein and a nonprotein (referred to as “prothetic group”)
Functions of proteins (8)
-Enzymes
-Hormones
-Transport
-Immunoglobulins
-Structural
-Storage
-Energy source
-Osmotic force
Proteins that increase in quantity during inflammation
Positive acute phase proteins
Proteins that decrease in quantity during inflammation
Negative acute phase proteins
Positive acute phase proteins
-CRP
-Complement
-Fibrinogen
-Plasminogen activator inhibitor-1
-Alpha-2 macroglobulin
-Ferritin
-Ceruloplasmin
-Haptoglobin
-Alpha-1 Antiotrypsin
Negative acute phase proteins
-Albumin
-Transferrin
-Transthyretin (pre-albumin)
-Retinol-binding protein
-Antithrombin
-Transcortin
_____ % of each protein is bound nitrogen
16%
Where is does the breakdown of proteins primarily occur?
Liver
What are the most frequently analyzed proteins?
Plasma/serum proteins
What are the 2 main groups of proteins most frequently analyzed?
Albumin and globulins
What are the 4 types of globulins?
Alpha-1, Alpha-2, Beta, and Gamma
What is the calculation for albumin?
Total Protein - globulins
Another name for pre-albumin
Transthyretin
Which protein serves as a transport protein for triiodothyronine (T3) and thyroxine (T4)?
Pre-albumin
Which protein is critical in the transport of retinol (Vit A)?
Pre-albumin
What could low values of Pre-albumin may indicate?
-Nutritional deficiency
-Hepatic damage
-Negative acute phase inflammatory response
What could increased values of Pre-albumin indicate?
-Alcohol abuse
-Steroid therapy
-Chronic renal failure
What is the most abundant (highest concentration) protein found in plasma/serum?
Albumin
Reference range for Albumin
3.5 - 5.5 g/dL
or
35 - 55 g/L
What is albumins primary function?
Bind and transport various substances in blood
What could decreased albumin values indicate?
-Negative acute phase inflammatory response
-Liver &/or kidney disease
-Malnutrition
-Malabsorption
What could increased albumin values indicate?
Most commonly: Dehydration
