Proteins Questions Flashcards
How many amino acids are considered essential?
10
CO2 is carried by HbA as?
Carbamate
In the Henderson-Hasselbalch equation, if you need the pH of the buffer to be greater than the pKa of the acid that you will use to make the buffer, which of the following will you increase?
[Conjugate Base]
BPG stabilizes the “T” form of HbA via what type of interaction?
Salt Bridge
When a mutation compromises biologic function of HbA, the condition is termed what?
Hemoglobinopathy
When H+ binds to HbA, which form of HbA exists?
T Form
What is the oxidation state of Fe in myoglobin & hemoglobin?
2+
Which blood protein saturates with O2 at low pressures?
Myoglobin
Myoglobin releases O2 to the muscle tissue at which partial pressure of O2?
5 mmHg
True or False
Proline can be accommodated on any turn of the alpha-helix.
False
When blood glucose enters the RBC, it glycates the pendent chain of which amino acid?
Lysine
Primary structures of peptides are stabilized by what?
Covalent Peptide Bonds
What type of HbA acts as a buffer?
Deoxyhemoglobin
Beta pleated sheets derive their stability from what type of intermolecular force of attraction?
Hydrogen Bonds
Myoglobin is rich in what type of secondary structure?
Alpha Helicies
Reduced production of a & b subunits of HbA results in what?
Alpha & Beta Thalassemia
In the Henderson-Hasselbalch equation, if you need the pH of the buffer to be less than the pKa of the acid that you will use to make the buffer, what will you increase?
Molar Concentration of the Acid
Of the two types of beta sheets, in which is the hydrogen bond oriented perpendicular to the backbone of the polypeptide?
Antiparallel Beta Sheets
What type of proteins are enzymes?
Globular
What joins two adjacent strands of an antiparallel beta sheet?
Loops & Bends
What is the p50 value for HbA with O2?
26 mmHg
Which amino acid is the precursor to Tyrosine?
Phenylalanine
The porphyrin ring around the central Fe atom in Hemoglobin is also called what?
Tetrapyrrole
BPG stabilizes which form of hemoglobin?
T Form
The interior of myoglobin contains polar or non-polar groups?
Non-Polar Groups
What kind of protein is collagen?
Fibrous
True or False
pKa values do not depend on the properties of the medium.
False
Electrostative interaction are between what?
Positive & Negative Charges within or between Biomolecules
What value represents the affinity of Fe2+ in hemoglobin towards CO?
~200 times
How many amino acids make up the beta chain of hemoglobin?
146 Amino Acids
Which form of HbA binds to O2?
R Form
In the Henderson-Hasselbalch equation, if the [A-] is less than [HA] what is the relationship between pH & pKa?
pH is less than pKa
Define fatty acid
A long unbranched chain carboxylic acid containing 10 to 20 carbon atoms.
Which blood protein has a sigmoidal O2 binding curve?
Hemoglobin
Replacing the 6th amino acid of the beta chain of Glu of HbA with Val results in which disease?
Sickle Cell Anemia
Describe the hydrogen bonding in beta sheets.
Between CO & NH on two different polypeptide chains
If Fe in hemoglobin is oxidized to 3+, what disease results?
Methemoglobin
Which amino acid has a pyrrolidine side chain?
Proline
What are the subunits of Fetal Hemoglobin?
a2g2 (alpha2 gamma2)
Dehydration of carbonic acid is catalyzed by which enzyme?
Carbonic Anhydrase
When the acid is exactly half neutralized ([A-] = [HA]), what is the relationship between pH & pKa?
pH = pKa
The CO2 released from tissues & carried by HbA attaches to which terminal of the polypeptide chain?
N-Terminal
How many aminoacyl residues are present in loops?
More than 4
In what disease is Histidine (His F8) replaced by Tyrosine?
Hemoglobin M
In the Henderson-Hasselbalch equation, if the [A] > [HA], what is the relationship between pH & pKa?
pH > pKa
What amino acid is responsible for PKU?
Phenylalanine
In the Henderson-Hasselbalcg equation, if the [A] = [HA], what is the relationship between pH & pKa?
pH = pKa
Most biomolecules are what?
Amphipathic
True or False
Amino acids with a non-polar side chain are called hydrophilic.
False
What force is responsible for the stability of aplha-helicies?
Hydrogen Bonds
An increased concentration in RBCs because of a mutation of hemoglobin results in which disease?
Polycythemia
The surface of globular proteins contains hydrophilic or hydrophobic groups?
Hydrophilic
The complete turn of alpha helix contains an average of how many aminoacyl residues?
3.6
Which blood protein is monomeric?
Myoglobin
Which blood protein is a good transporter of O2?
Hemoglobin
How many heme units exist in hemoglobin?
4
What can denature the disulfide bond in peptides?
Reducing Agents
Salt bridges are comparable in strength to which other intermolecular bond?
Hydrogen Bonds
Oxidative metabolism produces which gas?
CO2
How many amino acids make up the alpha chain of hemoglobin?
141
True or False
Solubility of amino acids reflects their ionic character.
True
Which blood protein is a tetrameric structure?
Hemoglobin
The buffer range or buffer capacity is between what range?
pH ± 1.0
What group determines the properties of amino acids?
Pendant R Group
F8 in myoglobin refers to the ______ Histidine?
Proximal
How many aminoacyl residues join two polypeptide together in a beta bend?
4
The hydrogen bond in the alpha-helix is between which two species?
CO & NH