Amino Acids

Question 1

Essential Amino Acids PVT TIM HaLL

Answer 1

Phenylalanine, Valine, Tryptophan, Threonine, Isoleucine, Methionine, Histidine, Leucine, Lysine

Question 2

Glucogenic Amino Acids

“We met his valentine who is so sweet”

Answer 2

Methionine, Histidine, Valine

Question 3

Glucogenic and Ketogenic Amino Acids

Go PITTT! (alma matter)

Answer 3

Isoleucine, phenylalanine, threonine, tryptophan, tyrosine

Question 4

Ketongenic

“The only purely ketogenic amino acids”

Answer 4

Leucine, and Lysine

Question 5

Acidic Amino Acids

Answer 5

Aspartic Acid and Glutamic Acid

*Negatively charged at body ph

Question 6

Basic Amino Acids

“His Lys are basic”

Answer 6

Histidine, Lysine and Arginine

Arginine is most basic

Histidine has no charge at body ph

Arginine and histidine are required during periods of growth

Arginine and lysine are increased in histones which bin negatively charged DNA

Question 7

aliphatic side chains (organic compounds whose carbon atoms are linked in open chains, either straight or branched, rather than containing a benzene ring):

Answer 7

Leucine, Alanine, Valine Isoleucine, and Glycine

Question 8

_____ and _____ have linear/ straight aliphatic side chain

Answer 8

Gly and alanine have linear/ straight aliphatic side chain

Question 9

____, ____ and _____ contain branched aliphatic side chains therefore they are termed branched chain amino acids

Answer 9

Valine, Leucine and Isoleucine contain branched aliphatic side chains therefore they are termed branched chain amino acids

Question 10

Nonpolar Aliphatic

GIV (e) LAP dance

Answer 10

Glycine, Isoleucine, Valine, Leucine, Analine, Proline

Question 11

side chains containing Hydroxyl (-OH) groups:

Answer 11

Serine, threonine and tyrosine

Question 12

side chains containing Sulfur atoms:

Answer 12

Cysteine and methionine

Question 13

side chains containing acidic groups and their amides:

Answer 13

Aspartate (asp d.) Glutamate (glue,E)

Asparginine (asn, N) Glutamine (glu, Q)

Question 14

side chains containing basic groups:

Answer 14

With side chains containing basic groups: - Arginine, lysine and histidine

Question 15

side chains containing aromatic rings:

“http://”

Answer 15

With side chains containing aromatic rings: Histidine, tyrosine tryptophan, & phenylalanine

Question 16

Imino acid

Answer 16

Proline

*contributes to the formation of collagen

Question 17

Amino Acids with nonpolar side chains

“GAVe Too Much LIPP”

Answer 17

Glycine, Alanine, Valine, Tryptophan, Methionine, Leucine, Isoleucine, Phenylalanine, and Proline

Question 18

Uncharged Amino Acids with polar side chains

Answer 18

Hydroxyl: Serine, Threonine, Tyrosine

Sulfur: Cysteine

Amide: Asparagine, Glutamine

Question 19

Charged polar amino acids

Answer 19

Aspartic acid, Glutamic acid

Question 20

Amino acids with basic side chains

Answer 20

Lysine, Arginine, Histidine

At physiologic pH, the R groups of Lysine and Arginine are
fully ionized and positively charged

Question 21

Contributes to buffering role of proteins such as hemoglobin

Answer 21

Histidine

Question 22

Essential amino acids

Answer 22

Arg, Val, His, Leu, Ile, Lys, Met, Phe, Thr, Trp.

Question 23

Non- essential amino acids:

Answer 23

Gly, Ala, Ser, Cys, Asp, Asn, Glu, Gln, Tyr, Pro

• Synthesized in the body from the 10
essential amino acids.

Question 24

Glucogenic amino acids:

Answer 24

Gly, Ala, Ser, Cys, Glu, Gln, Pro, His, Arg, Met, Val, Asp, Asn

• Serve as precursor for the formation of glucose or glycogen

Question 25

Ketogenic amino acids:

Answer 25

Leu & Lys (purely ketogenic)

• Precursor for the formation of acetyl CoA

Question 26

Here at 6th position of β chain of Hb, Glutamate is replaced by Valine
•Clinical manifestation → ________

Answer 26

Sickle Cell

Question 27

Proline,
disrupts the conformation of the α helix, producing a bend
(Because the peptide bond nitrogen of proline lacks a hydrogen atom to
contribute to a hydrogen bond )

Question 28

Valine is an amino acid used in the synthesis of proteins. It contains an alpha-amino group, an alpha-carboxylic acid group, and a side chain isopropyl group making it a non-polar aliphatic amino acid.

Question 29

Arginine is a basic amino acid

Question 30

Cysteine is Sulphur containing amino acid.

Question 31

Phenylalanine is an aromatic amino acid.

Question 32

Tryptophan is also an aromatic amino acid

Question 33

_____ is the main phospholipid found in brain white matter, mainly myelinated axons of neurons, and is therefore the main white matter membrane phospholipid that would be visible on MRI in white matter lesions.

Answer 33

Sphingosine

Question 34

Isoleucine is a branched chain nonpolar, or hydrophobic amino acid. It is considered aliphatic since it does not contain a ringed structure as part of the side chain.

Answer 34

TAKEAWAY: Amino acids are categorized based on the properties of the side chain. Aromatic vs aliphatic is based on the presence of a ring structure. Polarity within an amino acid is generated by the presence of an oxygen, nitrogen or sulfur at its terminal end.

Question 35

Proline shares many properties with the aliphatic group, but is not considered aliphatic. Proline is formally NOT an amino acid, but an imino acid. Nonetheless, it is called an amino acid. Proline is not aromatic but is a nonpolar and hydrophobic amino acid. Despite being nonpolar, this amino acid is not considered to be aliphatic due to the ring structure within the side chain. Proline is unique to other amino acids since the side chain and alpha-amino N form a rigid, five-membered ring structure making it a secondary amino group.

Question 36

Aspartate or aspartic acid is aliphatic in nature because it does not contain a ring structure. However, it is polar due to the side chain containing a carboxylic acid.

Question 37

Phenylalanine is an aromatic nonpolar, or hydrophobic amino acid. Despite being nonpolar, this amino acid is not considered to be aliphatic due to the benzene ring within the side chain.

Question 38

Tyrosine is an uncharged polar, or hydrophilic amino acid. The benzene ring structure within the side chain makes this aromatic, not aliphatic. The hydroxyl group on the terminal end generates a polarity.

Question 39

Cysteine is an uncharged polar hydrophilic amino acid. It has a side chain that contains a sulfhydryl (-SH) group essential for the active site of many enzymes, as well as utilized in a manner to strengthen the structural integrity of proteins. They are found in tertiary and quaternary protein structures in which two cysteines are oxidized to form a covalent cross-link called a disulfide bond.

Answer 39

TAKEAWAY: Cysteine is an amino acid unique for having a free sulfhydryl group. This makes it capable of bonding with other cysteines in order to form a disulfide bond. This covalent bond is found in many tertiary and quaternary protein structures.

Question 40

Glycine is a hydrophobic amino acid, containing only a hydrogen as its side chain. Due to its small and compact size, it is integral for certain structures such as alpha-helices in secondary protein structures. It is also the most abundant amino acid found in the collagen triple helix for the same reason. However, glycine does not contain a sulfhydryl group necessary for the formation of disulfide bonds.

Question 41

Lysine is a positively charged hydrophilic amino acid, classified as basic due to its side chain containing an amino group. It is also an essential amino acid, and as such must be obtained from the diet. However, lysine does not contain a sulfhydryl group necessary for the formation of disulfide bonds.

Question 42

Methionine is an essential hydrophobic amino acid, containing an S-methyl thioether side chain. It is known to be the initiator codon, indicating the start of the coding region during mRNA translation. It is similar to cysteine in that it contains a sulfur in the side chain. However, this sulfur is not situated in a manner to chemically form the disulfide bonds that the sulfhydryl group in cysteine is capable of.

Question 43

Serine is a non-charged polar hydrophilic amino acid. It contains a free hydroxyl group capable of undergoing O-linked glycosylation. Due to this side chain, serine is also one of three amino acids commonly phosphorylated by kinases during eukaryotic cell signaling. However, serine does not contain a sulfhydryl group necessary for the formation of disulfide bonds.

Question 44

The plasma membrane is made up of a phospholipid bilayer with the hydrophobic tails inward and the hydrophilic heads on the outside. Several types of proteins associate with the plasma membrane in ways that coalesce with the membrane’s structural properties. The transmembrane protein in particular contains hydrophobic regions that pass through the membrane, as well as hydrophilic regions of the transmembrane protein exposed to the water on either side of the membrane. This region could contain any of the positively charged, negatively charged or non-charged polar hydrophilic amino acids.

Answer 44

TAKEAWAY: Amino acids can be categorized by the structural properties of their respective R-chains. One such way is whether they are hydrophilic or hydrophobic. For a transmembrane protein to interact with the aqueous environments on either side of the cell membrane, amino acids that are hydrophilic in nature must form that particular region of the protein.

Question 45

Isoleucine, along with alanine, valine, leucine, Glycine, proline, phenylalanine, methionine, and tryptophan are all hydrophobic amino acids. As such this amino acid would be found within the hydrophobic regions of the transmembrane protein interacting interiorly with the hydrophobic tails of the lipid molecules, in order to be sequestered away from water. This question was asking for a hydrophilic amino acid that would associate with the aqueous environments on either side of the cell membrane.

Question 46

Histidine is a weakly basic amino acid, containing an imidazole ring for a side chain. This ring has a pKa of 6.4-7.0, allowing this amino acid to function as an excellent buffering system. This side chain can thus be either positively charged (protonated) or neutral, depending on the environment it is in. Albumin has an abundance of histidine residues within its structure allowing for its enhanced ability to buffer the blood in comparison to globulin.

Answer 46

TAKEAWAY: Histidine is a unique amino acid capable of acting like a buffer, due to its imidazole side chain that has a pKa of 6.4-7.0. This side chain can be either positively charged (protonated) or neutral, depending on the environment it is in.

Question 47

Aspartate is a negatively charged hydrophilic amino acid, with an acidic side chain capable of reacting with other amino acids and proteins in the body. It has a pKa of 3.9, which is far too low to be able to buffer the blood.

Question 48

Arginine is a positively charged amino acid and precursor for the biosynthesis of nitric oxide. In addition, it is classified as a conditionally essential amino acid. However, arginine is not known to have any buffering capabilities.

Question 49

Leucine is a hydrophobic amino acid with a branched aliphatic side chain. It is one of two exclusively ketogenic amino acids in the body, the other being lysine. Leucine is also an essential amino acid. However, leucine is not known to have any buffering capabilities.

Question 50

Phenol is a hydrocarbon arranged in a ring-like three-dimensional structure. Aromatic compounds (e.g, benzene, phenol ringed), named for their fragrant properties, confer properties of hydrophobicity (lipid solubility) when added to amino acids and other organic compounds. Hydrophobic chemicals pass through the phospholipid bilayer of plasma membranes by simple diffusion.

Answer 50

TAKEAWAY - Aromatic compounds (e.g, benzene, phenol ringed), named for their fragrant properties, confer properties of hydrophobicity (lipid solubility) when added to amino acids and other organic compounds. Hydrophobic chemicals pass through the phospholipid bilayer of plasma membranes by simple diffusion.