Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOC 2200 > Amino acids overview > Flashcards

Amino acids overview Flashcards

1
Q

Amino acid:

A

a compound that contains
both an amino group and a carboxyl
group

(a)- amino group, (a)-carboxyl group, alpha (a) carbon, Side chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

(a)-Amino acid:

A

an amino acid in which the amino group
is on the carbon adjacent to the carboxyl group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Side chain:

A

Varies between different amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Amino Acids-Nomenclature:

A
  • 1,1- = (a) amino acid
    Example: glycine.

-1,2- = (B) amino acid
Example: β-alanine.

  • 1,3- = γ amino acid
    Example: γ-aminobutyric acid
    (GABA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Amino acids are the
building…

A

blocks of proteins

  • alphabet of 20 α-amino acids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

all proteins in bacteria to humans are
constructed…

A

from this same set of 20 amino
acids which is over 2 billion years old

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

amino acids vary in their…

A

properties of size,
shape, charge, hydrogen-bonding capacity
and chemical reactivity

-amino acids also have many common
properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The Protein Alphabet: (A-L)

A

A - Ala - alanine

C - Cys - cysteine

D - Asp - aspartate

E - Glu - glutamate

F - Phe - phenylalanine

G - Gly - glycine

H - His - histidine

I - ile - isoleucine

K - Lys - lysine

L - Leu - leucine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The Protein Alphabet: (M-Y)

A

M - Met - methionine

N - Asn - asparagine

P - Pro - proline

Q - Gln - glutamine

R - Arg - arginine

S - Ser - serine

T - The - threonine

V - Val - valine

W - Trp - trytophan

Y - Tyr - tyrosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The language of proteins

A

-Amino acids
(the alphabet)

  • Proteins
    (words)
  • Metabolic pathways
    (sentences)

-Biological processes (chapters)

-The cell
(the story)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

19 of the 20 common amino acids have

A

a chiral
α-carbon atom (glycine does not)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Threonine and isoleucine have

A

2 chiral carbons
each (4 possible stereoisomers each)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Mirror image pairs of amino acids are

A

are
designated L (levo) and D (dextro)

-Proteins are assembled from L-amino acids
(a few D-amino acids occur in nature)

-The L-amino acids are found in biological systems.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Configuration

A
  • An L-Amino acid has the H2N- on the left hand side
    when drawn in this FISCHER projection.
  • By contrast, most carbohydrates are D-configured

-In the R,S (priority) system, 19 of the vital 20 (a)-amino
acids are S, and one (cysteine) is R.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

D/L -configurations

A

D)

-the form of glyceraldehyde whose asymmetrical carbon atom has a hydroxyl group projecting to the right

L)

-whose asymmetrical carbon atom has a hydroxyl group projecting to the left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Amino Acids

A
  • Colorless, crystalline, water soluble
    substances
  • R group gives individuality
  • R group varies from a simple H to a
    complex phenyl ring
  • Classification reflects structural features
    or properties of R groups
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Important Properties of Amino Acids:

A
  1. They have the capacity to polymerize
  2. They have interesting acid base properties
  3. They have varied structure and chemical
    functionality
  4. They are chiral
18
Q

Amino acids are…

A

Ampholytes.

-They can act as either an acid or a base

-They are zwitterions or molecules that
have both a positive and a negative
charge

  • Because of their ionic nature they have
    extremely high melting temperatures
19
Q

Although (a)-amino acids are commonly
written in the…

A

unionized form, they are
more properly written in the zwitterion
(internal salt) form

20
Q

Most amino acids are…
(charge rates)

A

zwitterions.

  • Amino acids are zwitterions at neutral pH
    (contain negative and positive charged groups)
21
Q

In acid solution the basic amino group is…

A

protonated

22
Q

In neutral solution the
zwitterion is formed by

A

an internal acid-base
reaction.

23
Q

In basic solution the carboxylic acid…

A

group
is ionized

24
Q

Zwitterion Definition:

A

The form HA , with zero net charge,

25
Q

Isoelectric Point Definition:

A

The pH at which the zwitterion is the predominant
form

26
Q

The average pKa of an -carboxyl group is…

A

2.19,
which makes it considerably stronger acids than
acetic acid (pKa
4.76)

– The greater acidity is accounted for by the
electron-withdrawing inductive effect of the
adjacent -NH3
+ group

27
Q

Due to the electron-withdrawing inductive effect of the…

A

(a)-NH3
+ group, side chain -CO2H groups are also
stronger than acetic acid

– The effect decreases with distance from the -NH3
+ group.

Compare:

(a)-CO2H group of alanine (pKa
2.35) R = CH3

(B)-CO2H group of aspartic acid (pKa
3.86) R = HO2CCH2

(y)-CO2H group of glutamic acid (pKa
4.07) R = HO2CCH2CH2

28
Q

The average value of pKa
for an (a)-NH3
+ group is…

A

9.47, compared with a value of 10.60 for a primary
alkylammonium ion

29
Q

The isoelectric point, pI…

A

of an amino acid is the pH at
which the majority of its molecules in solution have no
net charge

– the pI for glycine, for example, falls between the pKa
values
for the carboxyl and amino groups

30
Q

pI equation:

A

pI = (pK1 + pK2) / 2

31
Q

Why does the same carboxyl group
have different pKa
values?

A

the dissociation constant of a
carboxyl group is different when it is in a different chemical
environment.

32
Q

Make pg 41 flashcard

A
33
Q

Protein modification

A

Further protein diversity is achieved by post-synthesis (AKA posttranslational) modification of proteins. Some are:

  1. Acetylation of N-terminal
  2. Proline and lysine oxidised to hydroxyproline
    and hydroxylysine
  3. Carboxylation of glutamate residues
  4. Glycosylation
  5. Phosphorylation (Ser, Thr, Tyr residues)
  6. Farnesylation
  7. Post-synthesis cleavage
  8. Glycation (diabetes)
34
Q

post-synthesis modifications to protein structure add…

A

precision
to the regulation of protein activity inside and outside the cell

35
Q

Post-Translational Modification

A

The repertoire of side chain functionality is embellished by the ability of
some amino acids to be chemically modified after translation:

36
Q

Non-standard amino acids
not found in proteins

A

Ornithine and citrulline are intermediates in biosynthesis

37
Q
A
38
Q

Amino Acid Derivatives:

A
  • Visible symptoms of allergies are caused by the release of histamine
    in mast cells
  • Serotonin, which is derived from tryptophan, functions as a
    neurotransmitter and regulator.
39
Q

Essential Amino Acids
(EAAs)

A
  • Amino acids that the body cannot metabolize
    or make on its own in sufficient quantities
  • Therefore EAAs must be consumed in the diet
  • Usually considered to be from 8-10 amino
    acids
    –developing children may need more of certain
    amino acids and therefore they may be
    considered essential to their diet
40
Q

Essential Amino Acids:

A
  • 10 amino acids not synthesized by the body
  • arg, his, ile, leu, lys, met, phe, thr, trp, val
  • Must obtain from the diet
  • All in dairy products
  • 1 or more missing in grains and vegetables
41
Q

Other required amino acids

A
  • Special cases where more of certain amino acids are needed
  • Newborn children

– need more growth promoting aa’s -
arginine, taurine and cystine

  • Disease states (eg. alcoholics)
42
Q

Slide 80

A

BIOC 2200 (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions