2.1: The structure of RNA and DNA Flashcards Preview

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Flashcards in 2.1: The structure of RNA and DNA Deck (65):
1

Nucleic acids are a group of the most what molecules?

Nucleic acids are a group of the most important molecules

2

Nucleic acids are a group of the most important molecules, of which the best known are what?

Nucleic acids are a group of the most important molecules, of which the best known are:
1. Deoxyribonucleic acid (DNA)
2. Ribonucleic acid (RNA)

3

The what structure of DNA makes it what?

The double helix structure of DNA makes it immediately recognisable

4

What does DNA carry?

DNA carries genetic information

5

Despite its complex structure, what is DNA made up of?

Despite its complex structure, DNA is made up of nucleotides

6

Despite its complex structure, DNA is made up of nucleotides that have what?

Despite its complex structure, DNA is made up of nucleotides that have just 3 basic components

7

What are individual nucleotides made up of?

Individual nucleotides are made up of 3 components, a:
1. Pentose sugar
2. Phosphate group
3. Nitrogen-containing organic base

8

Individual nucleotides are made up of 3 components, a pentose sugar (so called because it has what), a phosphate group and a nitrogen-containing organic base?

Individual nucleotides are made up of 3 components, a:
1. Pentose sugar (so called because it has 5 carbon atoms)
2. Phosphate group
3. Nitrogen-containing organic base

9

Individual nucleotides are made up of 3 components, a pentose sugar (so called because it has 5 carbon atoms), a phosphate group and a nitrogen-containing organic base.
What are these nitrogen-containing organic bases?

These nitrogen-containing organic bases are:
1. A - Adenine
2. C - Cytosine
3. G - Guanine
4. T - Thymine
5. U - Uracil

10

Individual nucleotides are made up of 3 components, a pentose sugar (so called because it has 5 carbon atoms), a phosphate group and a nitrogen-containing organic base.
The pentose sugar, phosphate group and organic base are joined, as a result of what, to form what?

The:
1. Pentose sugar
2. Phosphate group
3. Organic base
are joined, as a result of condensation reactions, to form a single nucleotide (mononucleotide)

11

Individual nucleotides are made up of 3 components, a pentose sugar (so called because it has 5 carbon atoms), a phosphate group and a nitrogen-containing organic base.
The pentose sugar, phosphate group and organic base are joined, as a result of condensation reactions, to form a single nucleotide (mononucleotide).
2 mononucleotides may, in turn, be joined as a result of a condensation reaction between what?

2 mononucleotides may, in turn, be joined as a result of a condensation reaction between the:
1. Deoxyribose sugar of one mononucleotide
2. Phosphate group of another

12

Individual nucleotides are made up of 3 components, a pentose sugar (so called because it has 5 carbon atoms), a phosphate group and a nitrogen-containing organic base.
The pentose sugar, phosphate group and organic base are joined, as a result of condensation reactions, to form a single nucleotide (mononucleotide).
2 mononucleotides may, in turn, be joined as a result of a condensation reaction between the deoxyribose sugar of one mononucleotide and the phosphate group of another.
What is the bond formed between them called?

The bond formed between them is called a phosphodiester bond

13

Individual nucleotides are made up of 3 components, a pentose sugar (so called because it has 5 carbon atoms), a phosphate group and a nitrogen-containing organic base.
The pentose sugar, phosphate group and organic base are joined, as a result of condensation reactions, to form a single nucleotide (mononucleotide).
2 mononucleotides may, in turn, be joined as a result of a condensation reaction between the deoxyribose sugar of one mononucleotide and the phosphate group of another.
The bond formed between them is called a phosphodiester bond.
What is the new structure called?

The new structure is called a dinucleotide

14

Individual nucleotides are made up of 3 components, a pentose sugar (so called because it has 5 carbon atoms), a phosphate group and a nitrogen-containing organic base.
The pentose sugar, phosphate group and organic base are joined, as a result of condensation reactions, to form a single nucleotide (mononucleotide).
2 mononucleotides may, in turn, be joined as a result of a condensation reaction between the deoxyribose sugar of one mononucleotide and the phosphate group of another.
The bond formed between them is called a phosphodiester bond.
The new structure is called a dinucleotide.
The continued linking of mononucleotides in this way forms a long chain known as what?

The continued linking of mononucleotides in this way forms a long chain known as a polynucleotide

15

Individual nucleotides are made up of 3 components, a pentose sugar (so called because it has 5 carbon atoms), a phosphate group and a nitrogen-containing organic base.
The pentose sugar, phosphate group and organic base are joined, as a result of condensation reactions, to form a single nucleotide (mononucleotide).
2 mononucleotides may, in turn, be joined as a result of a condensation reaction between the deoxyribose sugar of one mononucleotide and the phosphate group of another.
The bond formed between them is called a phosphodiester bond.
The new structure is called a dinucleotide.
The continued linking of mononucleotides in this way forms a long chain known as a polynucleotide.
In addition to DNA and RNA, some other what molecules contain nucleotides?

In addition to:
1. DNA
2. RNA
,some other biologically important molecules contain nucleotides

16

'Thymine' is a base in DNA, but what is 'thiamine'?

'Thymine' is a base in DNA, but 'thiamine' is vitamin B1

17

Don't get confused between DNA and proteins.
DNA is a sequence of bases, but proteins are a sequence of what?

1. DNA is a sequence of bases
,but
2. Proteins are a sequence of amino acids

18

Don't get confused between DNA and proteins.
DNA is a sequence of bases, but proteins are a sequence of amino acids.
What join to form a polynucleotide and what join to form a polypeptide?

1. Nucleotides join to form a polynucleotide
2. Amino acids join to form a polypeptide

19

Ribonucleic acid (RNA) structure:
Ribonucleic acid is a polymer made up of what?

Ribonucleic acid is a polymer made up of nucleotides

20

Ribonucleic acid (RNA) structure:
Ribonucleic acid is a polymer made up of nucleotides.
RNA is a what chain?

RNA is a:
1. Single
2. Relatively short
3. Polynucleotide
chain

21

Ribonucleic acid (RNA) structure:
Ribonucleic acid is a polymer made up of nucleotides.
RNA is a single, relatively short, polynucleotide chain in which the pentose sugar is always what?

RNA is a:
1. Single
2. Relatively short
3. Polynucleotide
chain in which the pentose sugar is always ribose

22

Ribonucleic acid (RNA) structure:
Ribonucleic acid is a polymer made up of nucleotides.
RNA is a single, relatively short, polynucleotide chain in which the pentose sugar is always ribose and what are the organic bases?

RNA is a single, relatively short, polynucleotide chain in which the:
1. Pentose sugar is always ribose
2. Organic bases are A, U, C and G

23

Ribonucleic acid (RNA) structure:
Ribonucleic acid is a polymer made up of nucleotides.
RNA is a single, relatively short, polynucleotide chain in which the pentose sugar is always ribose and the organic bases are A, U, C and G.
What does one type of RNA do?

One type of RNA transfers genetic information from DNA to the ribosomes

24

Ribonucleic acid (RNA) structure:
Ribonucleic acid is a polymer made up of nucleotides.
RNA is a single, relatively short, polynucleotide chain in which the pentose sugar is always ribose and the organic bases are A, U, C and G.
One type of RNA transfers genetic information from DNA to the ribosomes.
What are the ribosomes themselves made up of?

The ribosomes themselves are made up of:
1. Proteins
2. Another type of RNA

25

Ribonucleic acid (RNA) structure:
Ribonucleic acid is a polymer made up of nucleotides.
RNA is a single, relatively short, polynucleotide chain in which the pentose sugar is always ribose and the organic bases are A, U, C and G.
One type of RNA transfers genetic information from DNA to the ribosomes.
The ribosomes themselves are made up of proteins and another type of RNA.
What is a third type of RNA involved in?

A third type of RNA is involved in protein synthesis

26

DNA structure:
In what year, who worked out the structure of DNA?

In 1953:
1. James Watson
2. Francis Crick
worked out the structure of DNA

27

DNA structure:
In 1953, James Watson and Francis Crick worked out the structure of DNA, following what by who?

In 1953:
1. James Watson
2. Francis Crick
worked out the structure of DNA, following pioneering work by Rosalind Franklin

28

DNA structure:
In 1953, James Watson and Francis Crick worked out the structure of DNA, following pioneering work by Rosalind Franklin on what?

In 1953:
1. James Watson
2. Francis Crick
worked out the structure of DNA, following pioneering work by Rosalind Franklin on the X-ray diffraction patterns of DNA

29

DNA structure:
In DNA, what is the pentose sugar?

In DNA, the pentose sugar is deoxyribose

30

DNA structure:
In DNA, the pentose sugar is deoxyribose and what are the organic bases?

In DNA, the:
1. Pentose sugar is deoxyribose
2. Organic bases are A, T, C and G

31

DNA structure:
In DNA, the pentose sugar is deoxyribose and the organic bases are A, T, C and G.
What is DNA made up of?

DNA is made up of 2 strands of nucleotides (polynucleotides)

32

DNA structure:
In DNA, the pentose sugar is deoxyribose and the organic bases are A, T, C and G.
DNA is made up of 2 strands of nucleotides (polynucleotides).
Each of the 2 strands is what and they are joined together by what formed between where?

Each of the 2 strands is extremely long and they are joined together by hydrogen bonds formed between certain bases

33

Base pairing:
The bases on the 2 strands of DNA attach to each other by what bonds?

The bases on the 2 strands of DNA attach to each other by hydrogen bonds

34

Base pairing:
The bases on the 2 strands of DNA attach to each other by hydrogen bonds.
It is these hydrogen bonds that hold the 2 strands together.
What is the base pairing?

The base pairing is specific

35

Base pairing:
The bases on the 2 strands of DNA attach to each other by hydrogen bonds.
It is these hydrogen bonds that hold the 2 strands together.
The base pairing is specific.
What are the base pairs?

The base pairs are:
1. A and T
2. G and C

36

Base pairing:
The bases on the 2 strands of DNA attach to each other by hydrogen bonds.
It is these hydrogen bonds that hold the 2 strands together.
The base pairing is specific.
A always pairs with T and G always pairs with C.
As a result of these pairings, A is said to be what and G is said to be what?

As a result of these pairings:
1. A is said to be complementary to T
2. G is said to be complementary to C

37

Base pairing:
The bases on the 2 strands of DNA attach to each other by hydrogen bonds.
It is these hydrogen bonds that hold the 2 strands together.
The base pairing is specific.
A always pairs with T and G always pairs with C.
As a result of these pairings, A is said to be complementary to T and G is said to be complementary to C.
It follows that the quantities of A and T and C and G in DNA are always the same.
However, what varies from species to species?

The ratio of:
1. A and T
to
2. G and C
varies from species to species

38

In every molecule of DNA, what are always the same?

In every molecule of DNA, the:
1. Phosphate group
2. Deoxyribose
3. 4 bases
are always the same

39

In every molecule of DNA, the phosphate group, the deoxyribose and the 4 bases are always the same.
What differs between one DNA molecule and another one are what?

What differs between one DNA molecule and another one are the:
1. Proportions
2. More importantly, the sequence
,of each of the 4 bases

40

In order to appreciate the structure of DNA, you need to imagine the ladder-like arrangement of the 2 polynucleotide chains being twisted.
In this way, what wind around one another to form a double helix?

In this way, the uprights of:
1. Phosphate
2. Deoxyribose
wind around one another to form a double helix

41

Why is DNA a stable molecule?

DNA is a stable molecule, because:
1. The phosphodiester backbone protects the more chemically reactive organic bases inside the double helix
2. Hydrogen bonds link the organic base pairs

42

DNA is a stable molecule, because the phosphodiester backbone protects the more chemically reactive organic bases inside the double helix and hydrogen bonds link the organic base pairs, forming what between what?

DNA is a stable molecule, because:
1. The phosphodiester backbone protects the more chemically reactive organic bases inside the double helix
2. Hydrogen bonds link the organic base pairs, forming bridges (rungs) between the phosphodiester uprights

43

DNA is a stable molecule, because the phosphodiester backbone protects the more chemically reactive organic bases inside the double helix and hydrogen bonds link the organic base pairs, forming bridges (rungs) between the phosphodiester uprights.
As there are how many hydrogen bonds between C and G, the what the proportion of what, the more stable the DNA molecule?

As there are 3 hydrogen bonds between:
1. C
2. G
,the higher the proportion of C - G pairings, the more stable the DNA molecule

44

DNA is the hereditary material responsible for passing genetic information from what?

DNA is the hereditary material responsible for passing genetic information from:
1. Cell to cell
2. Generation to generation

45

DNA is the hereditary material responsible for passing genetic information from cell to cell and generation to generation.
In total, there are around how many base pairs in the DNA of a typical mammalian cell?

In total, there are around 3.2 billion base pairs in the DNA of a typical mammalian cell

46

DNA is the hereditary material responsible for passing genetic information from cell to cell and generation to generation.
In total, there are around 3.2 billion base pairs in the DNA of a typical mammalian cell.
What does this vast number mean?

This vast number means that there is an almost infinite variety of sequences of bases along the length of a DNA molecule

47

DNA is the hereditary material responsible for passing genetic information from cell to cell and generation to generation.
In total, there are around 3.2 billion base pairs in the DNA of a typical mammalian cell.
This vast number means that there is an almost infinite variety of sequences of bases along the length of a DNA molecule.
It is this variety that provides what?

It is this variety that provides the genetic diversity within living organisms

48

The DNA molecule is adapted to carry out its functions in a number of ways:
1. It is a very stable structure, which normally passes from generation to generation how?

DNA is a very stable structure, which normally passes from:
1. Generation
to
2. Generation
without change

49

The DNA molecule is adapted to carry out its functions in a number of ways:
1. It is a very stable structure, which normally passes from generation to generation without change.
Only rarely does DNA do what?

Only rarely does DNA mutate

50

The DNA molecule is adapted to carry out its functions in a number of ways:
1. It is a very stable structure, which normally passes from generation to generation without change.
Only rarely does DNA mutate.
2. Its 2 separate strands are joined only with what?

DNA's 2 separate strands are joined only with hydrogen bonds

51

The DNA molecule is adapted to carry out its functions in a number of ways:
1. It is a very stable structure, which normally passes from generation to generation without change.
Only rarely does DNA mutate.
2. Its 2 separate strands are joined only with hydrogen bonds, which allow them to do what?

DNA's 2 separate strands are joined only with hydrogen bonds, which allow them to separate during:
1. DNA replication
2. Protein synthesis

52

The DNA molecule is adapted to carry out its functions in a number of ways:
1. It is a very stable structure, which normally passes from generation to generation without change.
Only rarely does DNA mutate.
2. Its 2 separate strands are joined only with hydrogen bonds, which allow them to separate during DNA replication and protein synthesis.
3. It is an extremely large molecule and therefore carries what?

DNA:
1. Is an extremely large molecule
2. Therefore carries an immense amount of genetic information

53

The DNA molecule is adapted to carry out its functions in a number of ways:
1. It is a very stable structure, which normally passes from generation to generation without change.
Only rarely does DNA mutate.
2. Its 2 separate strands are joined only with hydrogen bonds, which allow them to separate during DNA replication and protein synthesis.
3. It is an extremely large molecule and therefore carries an immense amount of genetic information.
4. By having the base pairs within what, the genetic information is to some extent protected from being what?

By having the base pairs within the helical cylinder of the deoxyribose-phosphate backbone, the genetic information is to some extent protected from being corrupted by outside:
1. Chemical
2. Physical
forces

54

The DNA molecule is adapted to carry out its functions in a number of ways:
1. It is a very stable structure, which normally passes from generation to generation without change.
Only rarely does DNA mutate.
2. Its 2 separate strands are joined only with hydrogen bonds, which allow them to separate during DNA replication and protein synthesis.
3. It is an extremely large molecule and therefore carries an immense amount of genetic information.
4. By having the base pairs within the helical cylinder of the deoxyribose-phosphate backbone, the genetic information is to some extent protected from being corrupted by outside chemical and physical forces.
5. What does base pairing lead to?

Base pairing leads to DNA being able to:
1. Replicate
2. Transfer
information as mRNA

55

What does the function of the remarkable molecule that is DNA depend on?

The function of the remarkable molecule that is DNA depends on the sequence of base pairs that is possesses

56

Nucleic acids are large molecules contained where?

Nucleic acids are large molecules contained in the nucleus of cells

57

Nucleic acids are large molecules contained in the nucleus of cells (hence the name).
Nucleic acids are composed of monomers called nucleotides.
A nucleotide is composed of 3 subunits (one phosphate group, one pentose sugar and one organic nitrogenous base.
These subunits are joined by what to form what?

These subunits are joined by covalent bonds to form a nucleotide molecule

58

In DNA, the sugar is what, whereas in RNA, what is the sugar?

In:
1. DNA, the sugar is deoxyribose
,whereas
2. RNA, the sugar is ribose

59

Features of nucleotides:
DNA and RNA have the same what, but a different pentose sugar and different what?

DNA and RNA have:
1. The same phosphate group
,but:
2. A different pentose sugar
3. Different base pairs

60

Apart from U in place of T, RNA is different to DNA in how many other ways?

Apart from U in place of T, RNA is different to DNA in 2 other ways - The:
1. Sugar is ribose, not deoxyribose
2. Nucleotide strand is a single strand, not double

61

Apart from U in place of T, RNA is different to DNA in 2 other ways - The sugar is ribose, not deoxyribose and the nucleotide strand is a single strand, not double.
Also, there are 2 different kinds of what?

Also, there are 2 different kinds of DNA:
1. Messenger RNA (mRNA)
2. Transfer RNA (tRNA)

62

There are 5 bases (A, T, C, G and U), split into what?

There are 5 bases (A, T, C, G and U), split into 2 types:
1. Purine bases
2. Pyrimidine bases

63

There are 5 bases (A, T, C, G and U), split into 2 types - Purine bases and pyrimidine bases.
What are the purine bases?

The purine bases are:
1. A
2. G

64

There are 5 bases (A, T, C, G and U), split into 2 types - Purine bases and pyrimidine bases.
What are the pyrimidine bases?

The pyrimidine bases are:
1. T
2. C
3. U

65

What are the 2 antiparallel strands in DNA held together by?

The 2 antiparallel strands in DNA are held together by hydrogen bonds