Amino Acids and Proteins Flashcards
(86 cards)
1
Q
What is the basic structure of a single amino acid?
A
It contains at least one amino group and one carboxyl functional group
2
Q
True or False: Amino acids can have neutral, positive and negative functional group but their net charge is going to be neutral.
A
True, classified as zwitterions.
3
Q
How do amino acids differ from one another?
A
by their chemical composition of their R groups, referred as side chains.
4
Q
True or False: The amino group of one amino acid cannot be covalently linked with a carboxyl group of another.
A
False, the amino group of one amino acid can be covalently linked with a carboxyl group of another, thus forming a peptide bond.
5
Q
Peptide bond
A
when an amino group of one amino acid links with the carboxyl group of another amino acid
6
Q
Polypeptide
A
when a chain of amino acids is linked by peptide bonds
7
Q
Protein
A
a large polypeptide
8
Q
True or False: Proteins found in human plasma are usually between 100 and 150 amino acids in the length of their polypeptide chains.
A
True
9
Q
Amino acids
A
are the building blocks of proteins
10
Q
The content and simple arrangement of amino acids in a specific protein are determined by?
A
the sequence of the nucleotide basis (the gene that encodes protein)
11
Q
In order to function correctly, what must proteins have?
A
the correct sequence of amino acids.
12
Q
Primary structure represents
A
the number and types of amino acids in the specific amino acid sequence.
13
Q
Secondary structure
A
refers to commonly formed structures stabilized by hydrogen bonds between the amino acids within the protein.
14
Q
What are the common secondary structures?
A
alpha-helix, beta-pleated sheet
15
Q
True or False: secondary structures add new properties to a protein such as strength and flexibility.
A
True
16
Q
The _________ of certain amino acids in a chain can help determine the secondary, tertiary, and potentially quaternary structure of a protein.
A
location
17
Q
Tertiary structure
A
refers to the overall shape, or conformation of the protein molecule.
18
Q
Conformation
A
is known as the fold, or the spatial relationship of the secondary structures to another one.
19
Q
The functional and physical and chemical properties of a protein are related to it’s
A
tertiary structure.
Tertiary structures are three dimensional and result form the interaction of side chains, which are stabilized through the hydrophobic effect, ionic attraction, hydrogen bonds, and disulfide bonds
20
Q
Quaternary structure
A
is the shape of structure that results from the interaction of more than one protein molecule, or protein subunits, held together by nonconvalent forces (such as hydrogen bonds and electrostatic interactions.)
21
Q
Which structure is described when a shape or structure, when you get interaction between more than one protein molecule in its tertiary structure?
A
Quaternary structure, also known as multiverse
22
Q
In order to get a quaternary structure, how many tertiary proteins will you have to come together and link up?
A
Two or more
23
Q
True or False: every protein has a quaternary structure
A
False
24
Q
What is denaturation?
A
When the secondary, tertiary, or quaternary structure of a protein is disturbed, and the protein lose its functional and chemical characteristics.
25
Denaturation can be caused by
heat, hydrolysis by strong acid or alkali, enzymatic action, exposure to urea, or other substances, or exposure to ultraviolet light.
26
True or False: protein digestion actually starts all the way up in the mouth
True.
27
Zwitterion
amino acids can have positive, neutral and negative parts, but their whole net charge is neutral.
28
Explain the process of digestion and absorption of dietary proteins
Starts at the mouth (mechanical digestion + some chemical digestion), goes to the stomach by swallowing (chemical digestion), in the stomach (pepsin breast down the proteins into peptides), in the small intestine (digestive enzymes secreted from the pancreas into the small intestine) - enzymes break down peptides into amino acids - amino absorption occurs, then it goes into the bloodstream, a small amount of dietary protein gets lost in the feces (going out through the large intestine).
29
Aminoacidopathies
are a class of inherited errors of metabolism in which there is an enzyme defect that inhibits the body's ability to metabolize certain amino acids
30
True or False: aminoacidopathies can exist only in activity of specific enzyme in metabolic pathway
False, aminoacidopathies can exist in either activity of specific enzyme in metabolic pathway or in membrane transport system for amino acids
31
Aminoacidopathies can cause severe medical conditions like
brain damage, death, just due to the accumulation of toxic amino acids and byproducts of amino acid metabolism in blood.
32
True or False: all states require screening for up to 26 amino acids
False: every state requires at least some, but the state you live in will vary what tests are screen for.
33
Over ____ diseases result from aminoacidopathies
100
34
Most babies are screen for a ___ test
PKU, called Phenylketonuria, which is a test that screens for one of the many aminoacidopathies.
Sample is collected within 24 hours of birth in a hospital, home birth is done by midwife or in outpatient.
35
Amino acid analysis' blood samples should be drawn after at least
6 to 8 hour fast.
36
The reason why you don't want any platelets or white cells aspirate up into the blood sample of an amino acid analysis test is because
the sample can have high levels of aspartic acid and glutamic acid, and you don't want any hemolysis
37
Isoelectric point
the pH at which an amino acid or protein has no net charge.
and that is dependent on how acidic or basic the medium that protein is in.
38
Adsorption of a protein
the protein's individual ability to have water playing to its surface; static
it helps maintain osmotic equilibrium
example: albumin
39
True or False: proteins can be used for specific binding to antibodies
True
40
True or False: proteins catalyze almost all reactions in living cell, so they virtually control all cellular processes in our bodies
true.
Some of their major functions include catalyze biochemical reactions and enzymes, transporting metals like iron and copper, acting like receptors for hormones, providing structures and support to cells, and participating in the immune response to antibodies.
41
What do proteins consist of?
carbon, oxygen, hydrogen, nitrogen, and sulfur
42
What sets proteins apart from pure carbohydrates and lipids?
they contain nitrogen
43
Simple Proteins
contain peptide chains composed of only amino acids. May be globular or fibrous in shape
44
Globular proteins
are globe-like and have symmetrical proteins that are soluble in water. They function as transporters, enzymes, and messengers.
Examples: albumin, hemoglobin, and the immunoglobulins.
45
Fibrous proteins
form long protein filaments or subunits, are asymmetrical and usually inert, and are generally water insoluble due to their hydrophobic R groups.
Examples: collagens, elastin's, and keratins
46
What are the protein functions?
-energy production
-water distribution
-buffering
-molecule transport
-glycoprotein production
-antibody production
-antibody production
-cellular protein production
-structural protein production
-enzyme production
-receptor
47
Complex or conjugated protein
consist of a protein and a nonprotein
they have more than on tertiary structure
48
List the conjugated proteins
-Nucleoproteins (DNA and RNA)
-Mucoproteins (Carbohydrates - >40% of total weight)
-Glycoproteins (Carbohydrates - 10-40% of total weight)
-Lipoproteins (Cholesterol, triglycerides, phospholipids)
-Enzymes (Aminotransferase, phosphtases)
-Hormones (Insulin, testosterone, TSH, cortisol)
-Immnunoglobulins (anitbodies- IgG, IgM etc.)
49
Plasma proteins
Albumin = ~54%
Globulins = ~46%
We don't measure globulins separately, we only measure total protein and albumin, so to find out your concentration of your globulins, you have to do math
Total protein - albumin = globulins
50
State the reference range for serum total protein ***
6.5-8.3 g/dL
51
State the reference range for and albumin***
3.5-5.5 g/dL
52
What are the different factors that can affect your plasma protein concentration?
-nutritional status
-physiological changes
-synthesis rate
-extracellular distribution
53
The albumin globulin (AG) ratio reference range
1.1-1.8
54
If we had a total protein of 8.1 and an albumin of 5.2. What would be the AG ratio? Is it normal?
1.) 8.1 - 5.2 = [2.9 ] globulin
2.) Albumin/globulin = 5.2/2.9 = 1.8
3.) Yes, it's normal. It is in the normal range.
55
If we had a total protein of 6.5 and albumin of 3.5. What is the the AG ratio? Is it normal?
1.) 6.5 -3.5 = [3] globulin
2.) Albumin/globulin = 3.5/3.0 = 1.2
3. Yes, it's normal. It is still in the normal range.
56
Can your albumin to higher than your total protein?
No. If your albumin is higher than your total protein you have a problem. It could be your analyzer, your reagent, your sample, there is an issue somewhere.
57
Prealbumin (transthyretin)
- It is not a precursor to albumin. It is before albumin in electrophoresis.
- Reference range serum: 10-20 mg/dL
- Reference range CSF: 0.0-3.1 mg/dL
- Transporter protein (T3/T4 and Vit A)
-Synthesized in liver and choroid plexus cells (half-life 2 days)
-What stimulates synthesis? (Glucocorticoid hormones, Androgens, Nonsteroidal anti-inflammatory drugs (NSAID's)
58
If you see a low prealbumin on a geriatric patient or a pediatric patient, it's an indication of ....
poor nutritional status.
It is a test that is ordered in order to assess whether or not somebody is getting adequate nutrition
59
Albumin
- Reference range: 3.5 - 5.5 g/dL
- ~54% of total protein ( 40% blood, 60% in extravascular space, CSF & Urine & amniotic fluid)
- Synthesized in the liver
-Function (Maintain colloid osmotic pressure - oncotic pressure)
-Function (Transport protein (fatty acids, phospholids, metallic ions, amino acids, drugs, hormones, and bilirubin))
-Factors affecting concentration (colloid osmotic pressure and protein intake)
60
Say a patient is over hydrated, they have plenty of albumin in their bodies, and their kidneys are functioning correctly. Will albumin cling to the water?
Yes, it will maintain that water status and their kidneys are going to flush out the rest that they don't need.
61
Say a patient has an issue with producing albumin. There is a possibility that they have liver damage, thus a lower amount of albumin in their extra vascular space. The albumin wants to go to those highly concentrated areas in their blood to the extra vascular space. When it does that, what happens with the water?
The albumin takes the water with it. It can cause edema in their peripheral tissues.
62
True or False: albumin tends to be decreased in liver disorders
True. The liver isn't producing it in GI conditions, because of malabsorption.
63
True or False: Muscle wasting diseases, severe burns, renal disease, starvation, and malnutrition will cause an decrease in albumin.
true
64
Kwashiokor (edit this)
-Kwashiokor is a type of malnutrition that usually occurs in famine and drought areas. It occurs due to insufficient protein in the diet. You're still getting calories, but it's not the calories you need.
-Symptoms: slow growth, weight loss, fatigue, irritability, muscle wasting, enlargement of the abdomen and live, skin changes, swelling, frequent infections, and weakening of the immune system.
- Seen in places where food is limited or in what food you have that is like a filler food like just rice.
So your body can still synthesize albumin, but it wants to escape to those peripheral tissues. So it takes water with it. Often gets into the abdomen and children will show a lot in their face.
65
Marasmus
a severe type of malnutrition that has the deficiency of both proteins and calories.
increase chance of chronic infection that can affect muscles and tissues. Can lead to insufficiency of vitamins and can lead to complete starvation.
66
Which disease occurs with severe protein deficiency?
Kwashiokor
67
Which disease has symptoms that includes: weight loss, dehydration, chronic diarrhea, and/or stomach shrinkage?
Marasmus
68
Which disease has symptoms that includes: Edema or puffy or swollen appearance due to fluid retention, bulging of the abdomen, and/ or inability to grow or gain weight?
Kwashiokor
69
Which disease decreases serum albumin levels and known cause is malnutrition?
Kwashiokor
70
Which disease has serum albumin levels not affected as much, tends to be more normal, but is known cause is overall starvation?
Marasmus
71
Alpha-1-antitrypsin
- 90% synthesized in liver
- secreted into circulation
- Protects elastin in the lungs by inhibiting neutrophil elastase
-acute phase reactive, protease inhibitor, it's main function is to inhibit the neutrophil elastase
72
True or false: if you have a decrease amount of alpha-1-antitrypsin, you can end up with damage to your lungs
True
73
Alpha-2-macroglobulin (edit this)
-is a major component of the alpha 2-macroglobulin fraction.
- it is a large protein (It can't cross the blood brain barrier and it can't cross the kidneys' glomeruli)
- it's a tertiary protein (synthesize in the liver)
-serine protease inhibitor (pepsin, trysin, thrombin, and plasmin
- Decreased in: inflammatory disorders, prostate cancer, acute pancreatitis
- Increased in: nephrotic syndrome, contraceptive use, pregnancy, estrogen therapy
- The measurement of this is very useful in evaluating renal disease and damage to the glomerulis.
-If you have a patient with kidney disease, you can see an 10% increase.
-It is a positive, acute phase reaction, both alpha-1 antitrypsin and alpha 2-macroglobulin will go up in acute inflammatory reaction. And albumin and prealbumin will go down
74
Haptoglobin
- alpha 2 glycoprotein synthesized in the liver as tetramer.
- Primary function is to bind free hemoglobin ( to prevent the lost of its constituent iron).
-Increased: inflammatory diseases, burns, trauma
-decreased: intravascular hemolysis because of the formation of a haptoglobin hemoglobin complex removal from the liver.
75
Ceruloplasmin
- synthesized in the liver (also macrophages and lymphocytes -less than 1%)
-Transport Protein for Copper (90% bound to ceruloplasmin)
-Positive acute phase reactant
-Increased: (inflammation, severe infection, tissue damage, pregnancy, estrogen use, some cancers, medication)
-Decreased levels:
- Primary (genetic) - Wilson's disease
- Secondary: malnutrition, or malabsorption, severe liver disease, nephrotic syndrome
Wilson's disease: Free copper is deposited in the liver, brain, and other organs and causes headaches, cirrhosis, neurologic DNA damage. Copper is also deposited in the cornea, which produces the characteristic gazer rings.
76
Transferrin
-synthesized in the liver
-transport iron and stores iron
-Increase levels in iron deficiency
- Decrease levels in iron overload, nephrotic syndrome, liver disease, inflammation.
-negative acute reactant
77
Fibrinogen
-synthesized in the liver
-It helps forms clot when activated by thrombin*****
-Increased levels in infection and pregnancy
-decreased levels in coagulation
-required serum on electrophoresis because it interferes with it.
78
C-reactive protein
- ref rang: 0
- positive acute reactant
- infection and tissue inflammation can result in a level >10 mg/dl
-anything above 1mg/dL is considered abnormal
-Elevated CRP levels stimulate the production of tissue factor, which initiates coagulation, activates complement, and binds to the LDL in an atherosclerotic plaque.
One reason why the high sensitivity therapy is used is it can help us evaluate risk of cardiovascular disease. C-reactive protein and HS-CRP are the same thing, but you're looking at different levels. HS-CRP is you're looking down.
79
Myoglobin
-ref rang: 10-95 ng/mL (serum) < or = 21 mcg/L (urine)
-Stores oxygen intracellularly
-Major muscle protein
-Functions: coordinates the oxygenation of hemoglobin by blocking other molecules, binds hemoglobin by trading the oxygen molecule
-Increased levels: Rhabdomyolysis, muscle injections, strenuous exercise, kidney failure
80
Other proteins of clinical significance
- Beta-2 microglobulin
- Troponin
- Fetal fibronectin
- BNP (B-type Natriuretic peptide)
- Cross-Linked C-Telopeptides (CTX)
81
Total protein abnormalities
-Hypoproteinemia
-Total protein level less than ref interval
-Occurs in any condition where a negative nitrogen balance exists
-Can be caused by excessive loss, decreased intake, decreased synthesis, or accelerated breakdown of proteins
-Hyperproteinemia
-An increase in total plasma proteins
-Occurs in dehydration, when concentration of proteins is elevated due to decreased volume of solvent water
- Also results from excessive production of proteins (gamma-globulins)
82
Total proteins****
-Most often measure in serum
-ref interval: 6.5 to 8.3 g/dL (65 to 85 g/L ) in ambulatory adults
-Method of measurement: Kjeldahl, refractometry, buret, dye binding
83
Methods of Analysis
fractionation, identification, and quantitation of specific proteins
-Salt fractionation: used of sodium salt to cause precipitation of globulins, leaving behind albumin, which can be measured
-Albumin: binding of positively charged albumin with anionic dye to electrostatic forces
-Total globulins: measurement of total globulin level in serum by direct colorimetric method using glyoxylic acid; albumin can then be calculated by subtracting globulin from total protein.
-Electrophoresis: separation of proteins on basis of electric charge densities
84
Urine protein (mircorprotein)
increased level: kidney failure, nephrotic syndrome, glomerulonephritis
-
85
CSF proteins*******
-central spinal fluid bathes the brain and spinal cord
-CSF is produced by the choroid plexus cells and brain ventricles
-CSF is reabsorbed through the arachnoid
-95% plasma protein and spinal fluid comes from the plasma
- 5% is made in the brain
-large (ish) proteins not found
-Permeability of brain barrier
-CSF albumin/Plasma albumin x 100 = no more than 65%
-If that ratio is 85%, you have a brain bleed.
86
Amphoteric
able to react both as a base and as an acid
