AS-Biology(*) > Nucleic acids > Flashcards

Nucleic acids Flashcards

(28 cards)

Study These Flashcards
1
Q

DNA and RNA are both polymers of _________

A

nucleotides

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

what are the 3 components in a nucleotide

A
  • phosphate group
  • pentose
  • nitrogen containing base
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe the structure of a DNA nucleotide

A
  • phosphate group
  • 5 carbon pentose sugar called deoxyribose
  • one of 4 nitrogen bases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the 4 bases in a DNA nucleotide

A
  • adenine
  • cytosine
  • guanine
  • thymine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

describe the structure of an RNA nucleotide

A
  • phosphate group
  • 5 carbon pentose sugar called ribose
  • one of 4 nitrogen bases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the 4 bases in an RNA nucleotide

A
  • adenine
  • cytosine
  • guanine
  • uracil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the diffeence between bases in DNA and RNA

A

in RNA uracil replaces thymine

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

how are dinucleotides formed

A
  • condensation reaction
  • between the phosphate group (5’ end) of one nucleotide and the ribose (RNA) or the deoxyribose (DNA) (3’ end) of another
  • the bond formed is called a phosphodiester
  • one molecule of water is produced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how are polynucleotides formed

A
  • more nucleotides are added by condensation reactions
  • many phosphodiester bonds form and these bonds form the sugar-phosphate “backbone” which is stable and strong
  • nucleotides can only be added in a 5’ - 3’ direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

name the molcule that catalyses the joining of nucleotides in the following:
1. DNA
2. RNA

A
  1. DNA polymerase
  2. RNA polymerase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

describe the structure of a DNA molecule

A
  • double helix with two polynucleotide chains held together by hydrogen bonds between specific complementary base pairs
  • both polynucelotide strands run in opposite directions, this means they are antiparralel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

structure of the DNA double helix:

A

DNA

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

what bonds and how many are formed between these base pairs:
1. adenine and thymine
2. cytosine and guanine

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

what is the function of DNA

A

hold genetic information

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

explain how this structure feature helps the function of DNA:

  • sugar phosphate backbone and double helix structure
A
  • provides strength and stability
  • protects information coded in the bases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

explain how this structure feature helps the function of DNA:

  • long molecule
Study These Flashcards
A

can store alot of information

17
Q

explain how this structure feature helps the function of DNA:

  • helix structure
18
Q

explain how this structure feature helps the function of DNA:

  • base sequence
Study These Flashcards
A

codes for amino acids

19
Q

explain how this structure feature helps the function of DNA:

  • double stranded
Study These Flashcards
A

allows semi-conservative replication beacause each strand can act as a template

20
Q

explain how this structure feature helps the function of DNA:

  • complemantary base pairing
Study These Flashcards
A

allows accurate replication

21
Q

explain how this structure feature helps the function of DNA:

  • weak hydrogen bonds between bases
Study These Flashcards
A

easily broken and seperation of strands for semi-conservative replication

22
Q

explain how this structure feature helps the function of DNA:

  • many hydrogen bonds in the whole molceule
Study These Flashcards
A

strong and stable molecule

23
Q

what is chargaffs base pairing rule

Study These Flashcards
A
  • adenine bonds with thymine and makes 2 H bonds
  • cytosine bonds with guanine and makes 3 H bonds
24
Q

what is mRNA

Study These Flashcards
A
  • messenger RNA
25
what is tRNA
* transfer RNA * single stranded polynucleotide folded into a cloverleaf shape * it brings amino acids to the ribosome during protein synthesis
26
what is rRNA
* ribosomal RNA * found in ribosomes along with protein
27
explain the steps of the process of semi conservative replication
1. The two strands of DNA seperate by breaking the hydrogen bonds between complementary base pairs. This is catalysed by **DNA helicase** 2. Each strand acts as a template and free DNA nucleotides are attracted to exposed complementary bases on the template strands 3. **DNA polymerase** joins together the nucleotides through condensation reactions that form phosphodiester bonds 4. Two DNA molecules are formed that each contain an original strand and a new strand
28
explain why polynucleotides are formed only in a 5' to 3' direction
* DNA polyermase has a specific active site that is complementary to the 5' end of the incoming free DNA nucleotide and the 3' end of the new strand
AS-Biology(*)
flashcards
Decks in class (22)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions