AMINO ACIDS PRACTICE QUESTIONS
FOR MCQs
1.
The R group in an amino acid specifies
a. Polarity
b. Individuality
c. Preference of reaction
d. Bond formation
2. All amino acids exist as α amino acids except
a. Glycine
b. Cysteine
c. Proline
d. Methionine
3. The simplest amino acid is
a. Glycine
b. Cysteine
c. Alanine
d. Valine
4. In the human body, all amino acids are S configured except
a. Glycine
b. Cysteine
c. Proline
d. Tryptophan
5. Glycine is the only amino acid that is
a. Achiral
b. Chiral
c. Isomeric
d. Simplicity
6. Amino acids do not have high boiling points above
a. 200-300⁰C
b. 300-400⁰C
c. 500⁰C
d. 350⁰C
7. What is the functional group of methionine
a. Diol
b. Thiol
c. Sulphide group
d. Indole
8. ỿ-carboxyl is the functional group of
a. gllutamne
b. arginine
c. aspartic acid
d. glutamic acid
9. All of the following amino acids are essential to the body except
a. Valine
a. Leucine
b. Alanine
c. Tryptophan
10. One of these amino acids are only essential during starvation
a. Serine
b. Histidine
c. Valine
d. Proline
11. Arginine contains both
a. Guanidino and amide group
b. Guanidinium and epsilum group
c. Guanidinium and amide group
d. Guanidino and epsilon groups
12. The structure
Is a derivative of;
a. Tyrosine
b. Histidine
c. Neurotransmitters
d. Threonine
13.The structure
are;
a. Citruline and orthinine
b. 4-hydroxyproline and 5-hydroxylysine
c. Citrulline and Ornithine
d. Azaserine and thyroxine
14. ------------- and ------------- are important components of protein collagen
a. 4-hydroxyleucine and 5-hydroxlysine
b. 4-hydroxyvaline and 5-hydroxyproline
c. 5-hydroxylysine and 4-hydroxyproline
d. Citrulline and Ornithine
15. An organic compound of amino acid sequence was weighed and found
to be 950KDa. This implies the compound is a
a. Peptidyl
b. Protein
c. Peptide
d. Polypeptide
16. What is the general absorbance rate of proteins
a. 280nm
b. 260nm
c. 230nm
d. 350nm
17. A patient was examined. During lab tests it was found he had
endothelial inflammation. What amino acid or it’s derivatives can best
treat the bacterial infection.
a. Histamine
b. Azaserine
c. 5-hydroxylysine
d. Homocysteine
18. What reaction amino acid will produce hydrindantin
a. Decarboxylation
b. Esterification
c. Biuret reaction
d. Non of the above
19. What is the functional group of methionine and arginine
a. Thioether and butylammonium
b. Thioether and guanidinium
c. Pyrrolidine and imidazole
d. Thiol and guanidinio
20. What forces that stabilize the structures of proteins
a. Hydrogen bonds, ionic and dispersion forces
b. Metallic bonds and vanderwaal forces
c. Peptide bonds and amide bonds
d. Amine, carboxylic and hydrogen bonds
21. The symbol of arginine is _____ Arg
22. All Amino acids are Assymetric: true or false .(ans. False)
That's a false statement! Not all amino acids are asymmetric. Amino acids
can be classified as either chiral or non-chiral. Chiral amino acids have an
asymmetric carbon atom in their structure, and therefore exist in two
different mirror-image forms, called enantiomers. Non-chiral amino acids
do not have an asymmetric carbon atom, and thus exist as a single form.
For example, glycine is a non-chiral amino acid, while phenylalanine is a
chiral amino acid.
23. Stereoisomers that are mirror images are called ___ Enantiomers.
The stereoisomers that are mirror images of each other are called
enantiomers. In chemistry, the term "enantiomer" refers to a pair of
compounds that have the same chemical formula and the same bond
connectivity, but they are mirror images of each other. When light passes
through a solution containing an enantiomer, the light is rotated either to
the left or to the right. The two enantiomers of a compound are often
referred to as the "right-handed" and "left-handed" forms.
24. Amino acid that must be obtained from the diet are called ___ Essential
The amino acids that must be obtained from the diet are called "essential
amino acids". Essential amino acids are the ones that our bodies cannot
synthesize in sufficient quantities, and therefore must be obtained through
the food we eat. There are nine essential amino acids, including histidine,
isoleucine, leucine, lysine, methionine, phenylalanine, threonine,
tryptophan, and valine. These amino acids are found in animal and plant
proteins, and are essential for the synthesis of proteins, hormones,
neurotransmitters, and other important molecules in the body.
25. Draw the structures of the following
Alannie, serine and Methionine
Ans.
Here are the structures of alanine, serine, and methionine:
Alanine: CH3-CH(NH2)-COOH
Serine: CH3-CH(OH)-CH(NH2)-COOH
Methionine: CH3-S-CH2-CH(NH2)-COOH
26. Give the abbreviation of the following
Histidine, threonine, Asparagine
Ans.
Here are the abbreviations for histidine, threonine, and asparagine:
Histidine: His
Threonine: Thr
Asparagine: Asn
27. Diasteroisomerism is a unique property of amino acids.
True/false ans. False
That statement is false. While it's true that some amino acids have stereoisomers,
this is not a unique property of amino acids. Stereoisomerism is actually a
property of all molecules that have a chiral center, and it's not specific to amino
acids. In fact, many other types of molecules, such as sugars and fatty acids, also
have stereoisomers. So while stereoisomerism is an important property of amino
acids, it's not unique to them.
28. The PH at which amino acids have equivalent positive and negative charges is
called ___ ans. Isoelectric point
"isoelectric point"! The isoelectric point (pI) of an amino acid is the pH at which
the overall charge of the amino acid is zero. At this point, the positive and
negative charges on the amino acid are balanced, and the molecule does not have
a net charge. The isoelectric point is determined by the amino acid's structure and
the individual charges on its side chain. For example, the isoelectric point of
alanine is 6.0, while the isoelectric point of arginine is 10.76.
29. The production of decarboxylation of histidine is ___Histamine
histamine"! Histidine can be decarboxylated to form histamine, a biogenic amine
that is involved in many physiological processes. Histamine is produced by a
specific enzyme called histidine decarboxylase, and it plays a role in inflammation,
allergies, and the regulation of stomach acid secretion. In the body, histamine is
stored in mast cells and basophils, and it is released in response to allergens,
irritants, and other stimuli.
30. The extend of amino acid solubility depends on ___, ___ and ___
Ans. Charge(polarity), size and hypophobicity.
The solubility of an amino acid depends on its charge, size, and hydrophobicity.
The charge of an amino acid is determined by the number of positive and
negative charges on its side chain, and it affects how well the amino acid can
interact with water. The size of an amino acid affects how well it can fit into the
solvent (usually water), while its hydrophobicity affects how well it interacts with
other molecules. All of these factors determine how soluble an amino acid is in a
solution.
31. Amino acid are colourless crystalline solid that are soluble in ___
Ans. Water
amino acids are generally colorless crystalline solids that are soluble in water! In
fact, amino acids have a high solubility in water due to the presence of both
hydrophilic and hydrophobic regions on their structures. The hydrophilic regions,
which are often polar or charged, interact with water molecules, while the
hydrophobic regions, which are often nonpolar, interact with each other. This
balance of interactions allows amino acids to be soluble in water.
32. All amino acids are called Alpha-amino acid except ___
Ans. Proline
all amino acids are classified as alpha-amino acids, except for proline! Proline is
considered a special case because it has a ring structure instead of a linear
structure like the other amino acids. In proline, the alpha-carbon atom is part of a
ring instead of being connected to a carboxyl group, an amino group, and two R
groups. This structure means that proline cannot form the typical hydrogen bonds
that other amino acids can form, and it has some different chemical properties as
a result.
33. All amino acids reacts with Ninhydrin to give a charcteristic yellow colour true
or false. (Ans. True)
34. ____ is the monomers of protein. Ans. Amino acid.
35. The connection between two amino acids residues is called a polypeptide.
True/false (Ans. False)
A polypeptide is not the connection between two amino acid residues, but rather
a long chain of amino acid residues. Two amino acid residues that are connected
by a peptide bond are called a dipeptide. A peptide is a chain of two or more
amino acid residues, and a polypeptide is a chain of many amino acid residues.
Proteins are made up of one or more polypeptides, and they can have complex
3D structures that perform a wide variety of functions in living organisms.
36. The interaction between different protein subunits is its _____ structure
Ans. D. Quaternary
That's the quaternary structure! The quaternary structure of a protein
refers to the way in which the protein's subunits (polypeptides) are
arranged and interact with each other. A protein can be made up of one or
more polypeptides, and each polypeptide can have a complex 3D structure
that allows it to interact with other polypeptides. The quaternary structure
determines the overall shape and function of the protein. Some proteins
have a very simple quaternary structure, while others are very complex.
37. Amino acids exist in aqueous solution as ____ (ans. A Zwitter ions)
In aqueous solution, amino acids exist in a form called zwitterions! Zwitterions are
molecules that have both positive and negative charges, making them neutral
overall. In an amino acid, the carboxyl group (-COOH) is acidic, while the amino
group (-NH2) is basic. In aqueous solution, the carboxyl group loses a proton (H+),
and the amino group gains a proton. This results in the amino acid having a
positive charge on the amino group and a negative charge on the carboxyl group.
38. The abbreviation of isoleucine is ___ (ans. c Ile)
39. ___ is an example of an imino acid. (Ans. Proline)
Proline is an example of an imino acid! An imino acid is a type of amino acid in
which the amino group (-NH2) is replaced with an imino group (-NH-). The imino
group is created when the amino group bonds with the alpha carbon of the amino
acid, forming a five-membered ring structure. In addition to proline, glycine and
hydroxyproline are also imino acids. Imino acids are important for the structure
and function of proteins, and they are often found in regions of the protein that
are important for folding or interaction with other molecules.
40. The monomer of protein is ___ (ans. B Amino acid)
49. Stereoisomer that are not mirror images of each other are called ___ (ans.
Diasteroisomers)
Stereoisomers that are not mirror images of each other are called diastereomers!
Diastereomers are molecules that have the same molecular formula and the same
connectivity of atoms, but they are arranged in different ways in space. This
means that they have different spatial orientations and are not mirror images of
each other. Diastereomers are often found in proteins, where they can influence
the protein's structure and function. The different spatial orientations of
diastereomers can lead to different interactions with other molecules, which can
have a significant impact on the protein's function.
50. The organelle involved in protein sorting, packaging and secretion is __ (ans.
Golgi Apparatus)
the Golgi apparatus! The Golgi apparatus is an organelle found in eukaryotic cells
that is involved in a variety of functions, including protein sorting, packaging, and
secretion. It consists of a series of flattened, membrane-bound sacs called
cisternae. Proteins are transported to the Golgi apparatus from the endoplasmic
reticulum (ER), where they are modified and sorted according to their final
destination.
51. The network of interconnecting membranes enclosing channels or outer
plasma membrane is called ____ ans.endoplasmic reticulum
the endoplasmic reticulum (ER)! The endoplasmic reticulum is a network of
membranes found in eukaryotic cells. It consists of two types: smooth ER and
rough ER. The smooth ER lacks ribosomes, while the rough ER is studded with
ribosomes. The rough ER is involved in the synthesis and transport of proteins,
while the smooth ER is involved in lipid synthesis, detoxification, and calcium
regulation. The ER is connected to the nuclear envelope, and it extends
throughout the cell, forming a network of interconnected membranes.
52. The biosynthesis of protein is referred to as __
Ans. D. Translation.
Protein translation is the process by which the genetic code in mRNA is translated
into a protein. It occurs in the ribosomes of the rough endoplasmic reticulum. The
mRNA is decoded into a sequence of amino acids, which are then linked together
to form a polypeptide chain. This process is catalyzed by the ribosome, and it
involves the use of transfer RNA (tRNA) molecules that carry amino acids to the
ribosome.