Brainscape's Knowledge GenomeTM

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


See full index

Biocheem > Lecture 10 > Flashcards

Lecture 10 Flashcards

1
Q

What is a proteins function determined by?

A

Its structure

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

What are the four parts to an amino acid?

A
  • Amine group
  • Carboxyl group
  • Alpha carbon
  • Variable R-group
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What varies between one amino acid an another?

A

The R-group

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

What is a Zwitterion?

A

A molecule that is overall neutral in terms of its net charge even though it has formal charges present because every molecules charge balances out

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

When is pKa smaller?

A

When an acid becomes stronger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the concentrations of acids and bases when pH = pKa?

A

[base] = [acid]. The concentration of the base equals the acid

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

What happens to the concentrations of the acid and base in the following situation?: pH < pKa

A

[acid] > [base]

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

What happens to the concentrations of the acid and base in the following situation?: pH > pKa

A

[acid] < [base]

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

What happens to the concentration of protons if pH is elevated?

A

The concentrated of protons goes down

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

What is the pKa of a carboxyl group for a typical amino acid?

A

pKa is around 2

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

What is the pKa of NH3?

A

Around 9.5

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

What happens to the carboxyl and amine group in a pH of 1?

A

The carboxyl becomes protonated and adds an it and is neutral and the NH3 keeps its H+ and become +1 making the overall molecule +1

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

What happen to carboxyl and amine at pH 11?

A

The carboxyl remains deprotonated (no H) and has a -1 charge and the amine group loses it H and is neutral making the overall molecule -1

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

What form of the carboxyl group and amine predominate at pH 7?

A

The carboxyl usually has the negative charge and the amine group usually has all 3 H’s and has a positive charge making the overall molecule neutral

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

What formal charge does an amino acid have at pH 7?

A

It has no formal charge

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

What is a chiral molecule?

A

An asymmetric molecule that cannot be superimposed on its mirror image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How are pH and protons related?

A

pH relates to the concentration of protons. The higher the pH the lower the concentration of protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What condition must the R have in order to ensure amino acids are chiral?

A

The R group must not be the same as any of the other three groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which form of stereoisomers is incorporated into proteins?

A

The L-form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How many amino acids are commonly incorporated into proteins?

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are amino acids classified by?

A

Their side chains (R groups)

22
Q

What are the 20 amino acids grouped on the basis of?

A
  • Nonpolar (hydrophobic)
  • Polar (uncharged)
  • Charged (very polar)
23
Q

What are the overall characteristics of an Hydrophobic Amino acids?

A
  • The side chain is largely hydrophobic

* The side chain usually contain carbon and hydrogen (except tryptophan and methionine)

24
Q

What is the relative size of alanine?

A

It is a relatively small amino acid

25
Q

What is the side chain of Alanine?

A

A methyl group

26
Q

What do aliphatic molecules contain?

A

Hydrocarbon structures that are non-aromatic, and saturated

27
Q

What is the smallest chiral amino acid?

A

Alanine

28
Q

What is the phobicity of Alanines side chain?

A

The CH3 sidechain is hydrophobic but because it is small it is not very hydrophobic it can still interact in hydrophobic interactions

29
Q

What is the size of Valine compared to Alanine?

A

Valine is larger than alanine

30
Q

Describe the R group of Valine?

A

Three carbons with the associated hydrogens

31
Q

What is the Aliphatic characteristics and phobicity of the side chain in Valine?

A
  • Aliphatic R group
  • Highly hydrophobic R group
  • Participates in hydrophobic interactions
32
Q

What is the Aliphatic characteristics and phobicity of the side chain in Leucine?

A
  • Aliphatic R group
  • Highly hydrophobic
  • Participates in hydrophobic interactions
33
Q

How many methyl groups bigger than Valine is Leucine?

A

Leucine is one methyl group bigger than Valine

34
Q

What is the Aliphatic characteristics and phobicity of the side chain in Isoleucine?

A
  • Aliphatic R group
  • Highly hydrophobic R group
  • Participates in hydrophobic interactions
35
Q

What is the three letter code for Isoleucine?

A

Ile

36
Q

Is the R group of Phenylalanine Aromatic or Aliphatic?

A

The R group is Aromatic

37
Q

What is the characteristics and phobicity of the side chain in Phenylalanine?

A
  • Aromatic R groups
  • Highly hydrophobic R group
  • Participates in hydrophobic interactions
38
Q

What are the characteristics of the R group of Tryptophan?

A
  • Aromatic R group (heterocyclic - contains more than one different atom)
  • Bulky hydrophobic
  • H bond donor
39
Q

Which Hydrophobic amino acid can form H bonds?

A

Tryptophan can be an H bond donor

40
Q

Which hydrophobic amino acids have aromatic R groups?

A
  • Phenylalanine

* Tryptophan

41
Q

Why is Tryptophan slightly polar?

A

Because the R group has a nitrogen that can be a hydrogen donor

42
Q

What is unique about Methionine?

A

It contains a sulfur atom within an thioether

43
Q

Is Methionine Aliphatic?

A

No it is not aliphatic because it contains a sulfur. It is an honorary aliphatic R group

44
Q

How does Methionine act in water?

A

It is hydrophobic and participates in hydrophobic interactions

45
Q

What two amino acids contain sulfur?

A

Methionine and cysteine

46
Q

Why is the Proline unique?

A

Because the R group is not exclusively attached to the alpha carbon

47
Q

Why can or can’t proline be described as aliphatic?

A

It is described as aliphatic because the side chain technically does contain only carbons and hydrogens but if you include its bond to the nitrogen is the it wouldn’t be aliphatic

48
Q

How is the amine group in proline different?

A

It is a secondary amino group instead of primary because the R group bonds with it

49
Q

/What is the Hydrophobicity of Proline

A

It is hydrophobic

50
Q

Despite Proline and Alanine being hydrophobic, what is unique about it?

A

Hydrophobic amino acids are generally found in the core participating in the hydrophobic effect but even though proline and alanine are hydrophobic it’s often found on the surface or proteins

Biocheem (38 decks)

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