KH 01 Flashcards

1
Q

What are 3 informational biopolymers?

A

DNA, RNA and protein

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

What is a polymer?

A

A covalent bond-linked chain of monomers

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

What is a sequence?

A

The order of the different kinds of monomer units in the polymer chain. It’s the information in an informational biopolymer. Different sequence = different information

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

In the case of DNA, RNA and protein, what would be the information?

A

The DNA sequence, the RNA sequence and the protein sequence

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

What are the 2 elements that form the common generic structure of informational biopolymers?

A

A common element (shared by all the different monomers) and a characteristic element (that makes each monomer different from the others)

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

What is the polymer backbone?

A

The common element of informational biopolymers “linked” by covalent bonding between monomers

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

What do the characteristic elements form that protrude form the polymer backbone?

A

Side-chains

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

If the monomer has one joining site in the common element, how many monomer units can be joined together?

A

Only two monomer units. It can only form a dimer (no other joining sites are exposed at the common element’s ends, there is no further chain growth)

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

If the monomer has two joining site in the common element, how many monomer units can be joined together?

A

Potentially infinite monomer units. We can make linear polymers (joining sites are exposed at the common element’s ends, further chain growth is possible)

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

If the monomer has three joining site in the common element, how many monomer units can be joined together?

A

Potentially infinite monomer units. We can make branched polymers.

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

Can cells make branched polymers?

A

Yes (ex: complex carbohydrates)

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

Can informational biopolymers make branched polymers?

A

No. Informational biopolymers are always linear and have two joining sites

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

Packaging and handling of (1) molecules may be more efficient than of (2) molecules

A
  1. Linear
  2. Branched
    (this is a good thing for scientific progress because it would have been harder to determine the structures if they had been branched)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In most cases, how many ends do linear informational biopolymers have?

A

2 ends, but in some cases, the two ends can be joined, giving an unbranched circular molecule (ex: viruses)

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

Are the monomers in informational biopolymers symmetric?

A

No, they are asymmetric. The two joining sites are different (there is an “A” end and a “B” end. A can only join with B, B can only join with A)

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

Is the informational polymer symmetric?

A

Like the monomers, the polymer is asymmetric. The “A” end and the “B” end are also chemically distinct

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

Polymer growth is…?

A

Unidirectional. For DNA, RNA and protein, growth of the chain occurs only at one end

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

What is the convention when showing biopolymer representations on a sheet of paper and depicting polymer growth?

A

Polymer chain growth is depicted in the rightward direction. New monomers are added at the right end

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

What is the typical chain length of DNA?

A

About 1000 to 100 million nucleotides

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

What is the typical chain length of RNA?

A

About 20 to 10 000 nucleotides

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

What are the nucleic acids’ (DNA, RNA) monomers?

A

Nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the proteins’ monomers?

A

Amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the typical chain length of protein?

A

About 100 to 1000 amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the nucleotides’ polymers?

A

Nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the amino acids’ polymers?

A

Protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the characteristic element in nucleotides?

A

A heterocyclic base (ex: adenine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the common element that form the polymer backbone in nucleotides?

A

A pentose sugar phosphate (ex: ribose)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the 2 joining sites on the nucleotide’s common element?

A

The 5’ phosphate (the acid in “nucleic acid”, has a negative charge) and the 3’ hydroxyl (OH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Nucleic acid polymer growth is always by addition of monomers to which end?

A

The 3’ end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What charge do nucleic acids have?

A

A strong negative charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The monomer polarity is reflected in the polymer, so we speak of the ___ end and the ___ end of a nucleic acid chain.

A

5’ end, 3’ end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the pentose sugar phosphate found in DNA?

A

Deoxyribose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the pentose sugar phosphate found in RNA?

A

Ribose

34
Q

What is deoxyribose missing compared to ribose?

A

The 2’ hydroxyl (OH)

35
Q

Why does DNA have a greater stability than RNA?

A

Because DNA’s deoxyribose is missing the 2’ - OH, which makes it much more resistant to chain cleavage by hydrolysis (more stable in water)

36
Q

What is the name of the bond that links the pentose sugar phosphate to the heterocyclic base?

A

The N-glycosidic bond

37
Q

What are the 2 purines?

A

Adenine and Guanine

38
Q

What are the 3 pyrimidines?

A

Uracil, Thymine and Cytosine

39
Q

Which pyrimidine is only found in RNA?

A

Uracil

40
Q

Which pyrimidine is only found in DNA?

A

Thymine

41
Q

What is the advantage of having thymine instead of uracil in DNA?

A

Thymine makes some chemical damage easier to repair

42
Q

Between purines and pyrimidines, which contain a pair of fused rings?

A

Purines

43
Q

Between purines and pyrimidines, which contain only a single ring?

A

Pyrimidines

44
Q

What is the bond between adjacent nucleotides?

A

A phosphodiester bond (diester because the phosphate is joined in an ester linkage to the 5’ OH of the downstream nucleotide and in another ester linkage to the 3’ OH of the upstream nucleotide)

45
Q

What is the characteristic element in amino acids?

A

The amino acid side chain (R)

46
Q

What is the common element that forms the polymer backbone in amino acids?

A

The alpha carbon liked to a COOH (carboxyl) group and a NH2 (amino group)

47
Q

What stereoisomers of amino acids are used in protein synthesis?

A

The L stereoisomers (not the D)

48
Q

What are the 2 joining sites on the amino acid’s common element?

A

The amino (NH2) group and the carboxyl (COOH) group

49
Q

The monomer polarity is reflected in the polymer, so we speak of the _____ and the _____ end of a protein.

A

amino terminus, carboxyl terminus / amino end, carboxyl end

50
Q

Protein polymer growth is always by addition of monomers to which end?

A

The carboxyl (COOH) end

51
Q

How many amino acid side chains are there?

A

20

52
Q

What are the main 3 classes of amino acids?

A

Hydrophobic (8 amino acids), hydrophilic (9 amino acids), and special (3 amino acids). Their chemical properties define them.

53
Q

What is the bond between adjacent amino acids?

A

A peptide bond

54
Q

How do the nucleic acids’ monomers have to be in order to be incorporated into the growing polymer chain?

A

“Energized”. They have to be in the form of high-energy nucleoside triphosphates (NTPs)

55
Q

What happens when the monomers are in the form of nucleoside triphosphates (NTPs) and are about to be incorporated into the growing polymer chain?

A

The outer 2 phosphates are “kicked out”

56
Q

How do the proteins’ monomers have to be in order to be incorporated into the growing polymer chain?

A

“Energized”. They have to be in the form of high-energy amino acyl-tRNA esters

57
Q

What happens when the monomers are in the form of amino acyl-tRNA esters and are about to be incorporated into the growing polymer chain?

A

The tRNA molecule is “kicked out”

58
Q

Can energized monomers join a growing chain by themselves?

A

No, the linkage reaction is catalyzed by a specific enzyme

59
Q

What are the respective templates of the biopolymers DNA, RNA and protein?

A

DNA, DNA, mRNA

60
Q

What are the respective enzymes of the biopolymers DNA, RNA and protein?

A

DNA polymerase, RNA polymerase, ribosome

61
Q

The enzyme is associated with a _____ biopolymer that directs the enzyme to incorporate the correct flavor monomer.

A

template

62
Q

How are DNA strands held together?

A

By H-bonds between complementary bases (Watson-Crick base pairs)

63
Q

DNA is generally in a ____-handed helix named “B” DNA

A

right

64
Q

Are the two DNA strands parallel or antiparallel?

A

Antiparallel

65
Q

RNA and protein usually exist as single polymer chains, but how does DNA exist?

A

As double-stranded, duplex DNA

66
Q

What can DNA-binding proteins do?

A

Make contact with base-pairs at the major or minor grooves and identify specific sequences without having to separate the strands

67
Q

How are sugar-phosphate backbones and base-pairs placed in the DNA structure?

A

Sugar-phosphate backbones are on the outside and base-pairs are stacked on the inside

68
Q

How do we call DNA strand separation?

A

Denaturation

69
Q

How does DNA strand separation occur?

A

By breaking the H-bonds that link the DNA strands together (ex: by heat, melting)

70
Q

What is renaturation?

A

Denatured DNA strands can accurately re-form base-paired duplex DNA by formation of H-bonds between complementary base-pair sequences

71
Q

DNA denaturation and renaturation are important during which biological processes?

A

DNA replication and transcription. They are also exploited in many experimental techniques in molecular biology and genomics

72
Q

What do we call the temperature at which the DNA is one-half melted?

A

The Tm

73
Q

What does the Tm depend on?

A

Its base composition

74
Q

DNA with a higher proportion of ___ base-pairs has a higher Tm (it takes a higher temperature to have the DNA one-half melted)

A

G-C

75
Q

Why does it take less energy to separate an A-T base-pair than a C-G base-pair?

A

Because A-T base-pairs have 2 H-bonds whereas C-G base-pairs have 3.

76
Q

Why is DNA like spaghetti?

A

Because it can bend about its long axis. This is an important property in DNA-protein interactions and in the folding of DNA into compact condensed structures

77
Q

Why do we call the link between adjacent nucleotides a phosphoDIESTER bond?

A

Because the phosphate is joined in an ester linkage to the 5’ OH of the downstream nucleotide and in another ester linkage to the 3’ OH of the upstream nucleotide

78
Q

What does upstream mean in biology?

A

The opposite direction in which a template DNA strand is transcribed

79
Q

What does downstream mean in biology?

A

The direction in which a template DNA strand is transcribed

80
Q

What do nucleoside triphosphate (NTPs) include in DNA?

A

Adenosine triphosphate (ATP), cytidine triphosphate (CTP), guanosine triphosphate (GTP) and uridine triphosphate (UTP)

81
Q

What do nucleoside triphosphate (NTPs) include in RNA?

A

Deoxyadenosine triphosphate (ATP), deoxycytidine triphosphate (CTP), deoxyguanosine triphosphate (GTP) and deoxyuridine triphosphate (UTP)