Practice Quiz 4 (amino acids, proteins)
You have 15 minutes to finish the quiz.
Q.1:
The 3 dimensional structure of proteins and their function is directly related to the chemical properties of amino acids side chains. Which of the following is
not
associated with amino acid side chains in proteins.
polar groups
hydrophobic groups
positively charged groups
sulfur containing groups
all of the above are found in proteins
Q.2 :
Which of the following groups of amino acids have ionic (charged) residues?
Ser, Thr, Tyr
Lys, Asp, Glu, His
Val, Ala, Leu
Cys, Gln, Asn
Q.3 :
The following is true for amino acid residues EXCEPT (the residue is the part of the molecule which is different in all amino acids)
the residue can have amino and carboxylic groups
the residue may contain sulfur
the residue may have OH groups
all are true
Q.4:
Which statement is
false
?
Glycine is a non essential amino acid
Glycine is not optically active
Glycine is a zwitter ion
all are true
Q.5:
Which amino acids are NOT commonly found in proteins?
alpha amino acids
aromatic amino acids
D-amino acids
optically active amino acids
Q.6 :
Which statement is false?
primary structure of proteins refers to the amino acid sequence
proteins are formed from amino acids in a condensation reaction
amino acid chains can interact via beta sheet formation
the quarternary structure of proteins refers to the interaction of proteins and carbohydrates
Q.7 :
Which of the following interactions have NO influence on the three dimensional folding of proteins (tertiary structure)?
polar and ionic interactions between sections of the protein chain
interaction between an OH group and a O=C group
sulfur - sulfur bridges
all of the above have an influence on the tertiary structure
Q.8 :
KSCN is a substance which is capable of forming strong H-bonds with H-N- and HO- groups. A concentrated aqueous solution of KSCN is added to a globular protein solution. Which of the following is
not
observed :
H-bonds within the alpha helix are disrupted
the addition helps non polar amino acids to form H-bonds
the three dimentional structure of the protein is disrupted (protein is denatured)
all of the above is observed
Q.9 :
Which are structural proteins:
blood proteins
some enzymes
alpha keratin
proteins have no structural function
Q.10 :
Which is not associated with proteins?
proteins work as catalysts in chemical reactions
proteins can transport substances across the biomembrane
proteins are hydrolysed by the cell to obtain energy
certain proteins function as hormones
collagen is a structural protein
all of the above are true