Amino Acids - Nitrogen Compounds

Question 1

What are amino acids?

Answer 1

Organic compounds containing amine + carboxylic acid functional group + side chain, which is specific to each amino acid

Question 2

What is the general formula for amino acids?

Answer 2

RCH(NH2)COOH

Question 3

How many amino acids is there?

Answer 3

20

Question 4

How do you name amino acids?

Answer 4

Prefix = amino
Suffix = _anoic acid
Number carbon which NH2 is attached to

Question 5

What is the name of CH3CH(NH2)COOH?

Answer 5

2 - amino propanoic acid

Question 6

What is the name of C6H5CH2CH(NH2)COOH

Answer 6

2 - amino 3 - phenyl propanoic acid

Question 7

What is the base group of an amino acid?

Answer 7

NH2

Question 8

What is the acid group of an amino acid?

Answer 8

COOH

Question 9

How is a zwitterion formed?

Answer 9

H from COOH is donated to NH2

Question 10

What should the charge of a zwitterion be?

Answer 10

Neutral

Question 11

When does a zwitterion form?

Answer 11

At isoelectric point

Question 12

What is an isoelectric point?

Answer 12

pH at which an amino acid exists as a zwitterion

Question 13

What happens to a zwitterion when pH increases

(H+ removed)?

Answer 13

H+ from NH3 is removed

Negative overall charge

Question 14

What happens to a zwitterion when pH decreases (H+ donated)?

Answer 14

H+ donated to COO-

Positive overall charge

Question 15

What is the isoelectric point affected by?

Answer 15

Different R groups

Question 16

Draw zwitterion for alanine (CH3) and increase + decrease of pH

Answer 16

LOOK AT NOTES

Question 17

Draw zwitterion for glutamic acid (CH2CH2COOH) and increase + decrease of pH

Answer 17

LOOK AT NOTES

Question 18

Draw zwitterion for LYSINE ((CH2)4NH2) and increase + decrease of pH

Answer 18

LOOK AT NOTES

Question 19

If you are increasing pH of a zwitterion that has COOH in its R group can you remove H+ from that as well?

Answer 19

YES

Question 20

Which group can you only remove H+ from?

Answer 20

COOH

Question 21

If you are decreasing pH of a zwitterion that has NH2 in its R group can you donate H+ to it as well?

Answer 21

YES

Question 22

What happens when an amino acid reacts with an acid?

Answer 22

To NH2 to from NH3+

Question 23

What is produced when CH3CH(NH2)COOH + HCl?

Answer 23

CH3CH(NH3+)COOHCl-

Question 24

What happens when an amino acid reacts with an alkali?

Answer 24

Metal reacts with COOH to form COO-Na+

Question 25

What is produced when CH3CH(NH2)COOH + NaOH?

Answer 25

CH3CH(NH2)COO-Na+ + H2O

Question 26

What is the general formula when an amino acid + alcohol?

Answer 26

COOH part + alcohol ⇌ ester + H2O

Question 27

What happens when an amino acid reacts with an alcohol?

Answer 27

OH from amino acid removed H from alcohol removed Join together to form ester H2O produced too

Question 28

What are the conditions needed for an amino acid reacting with an alcohol?

Answer 28

Heat Strong acid catalyst - H2SO4 Reversible reaction

Question 29

What is the problem sometimes with using H2SO4 as a strong acid catalyst when reacting an amino acid with an alcohol?

Answer 29

Sometimes donates H+ to NH2

Question 30

What is produced when CH3CH(NH2)COOH + CH3OH?

Answer 30

CH3(NH2)COOCH3 + H2O

Question 31

What is needed for a cis/trans isomer?

Answer 31

To have H as one of the groups

Question 32

What is needed for a E/Z isomer?

Answer 32

C=C | 2 different groups attached to each carbon

Question 33

What is a stereoisomer?

Answer 33

Isomer that has the same structural + molecular formula but a different spatial arrangement of atoms

Question 34

What is superimpose?

Answer 34

Place or lie over another and they are the exact same

Question 35

What does it mean if two molecules are identical?

Answer 35

You can superimpose them | BUT they are not isomers

Question 36

What does it mean if two molecules aren't identical?

Answer 36

Cannot superimpose | So ARE isomers (stereoisomers)

Question 37

What is optical isomerism?

Answer 37

2 isomers you can't superimpose

Question 38

What does an isomer have to have to be optical isomerism?

Answer 38

A carbon with 4 different groups attached

Question 39

What is a chiral centre?

Answer 39

A carbon with 4 different groups attached

Question 40

When identifying chiral centres what must you do?

Answer 40

Draw out displayed formula Draw on all C's and H's Identify with a star *

Question 41

What is called when one molecule has one chiral centre and they mirror image each other?

Answer 41

Enantiomers

Question 42

What is racemic mixture?

Answer 42

Both enantiomers in a mixture

Question 43

If a molecule has 1 chiral centre, how many isomers does it have?

Answer 43

2

Question 44

How do you find the other isomer of a molecule with one chiral centre?

Answer 44

Mirror image it

Question 45

If a molecule has 2 chiral centres, how may isomers does it have?

Answer 45

4

Question 46

How do you find the second isomer of an isomer with 2 chiral centres?

Answer 46

Mirror image the first

Question 47

How do you find the third isomer of an isomer with 2 chiral centres?

Answer 47

Draw mirror image of top half of isomer 1 but keep bottom part the same

Question 48

How do you find the fourth isomer of an isomer with 2 chiral centres?

Answer 48

Draw mirror image of bottom half of isomer 1 but keep top half the same

Question 49

How do you know it is an alpha amino acid?

Answer 49

COOH + NH2 attached to same carbon