DNA Replication

Question 1

DNA Name

Answer 1

Deoxyribonucleic Acid

Question 2

DNA

Answer 2

Nucleis acid polymer made of repeating monomers called nucleotides

Question 3

DNA Function

Answer 3

Stores + transmits the genetic instructions used to synthesize proteins

Question 4

DNA Monomer

Answer 4

Nucleotide

Question 5

Nucleotide Structure

Answer 5

Phosphate group + Pentose / Deoxyribose Sugar + Nitrogenous Base

Question 6

DNA Structure

Answer 6

Double helix; 2 strands of nucleotides held together by base pairing + twisted to form DH; Sugar-phosphate backbone

Question 7

Sides of Twisted Ladder Model of DNA

Answer 7

Sugar-phosphate backbone

Question 8

Rungs of Twisted Ladder Model of DNA

Answer 8

Base pairs (A-T, C-G)

Question 9

Nucleotide → Double Helix

Answer 9

Nucleotide (covalent bond joins nucleotides) → Strand (polynucleotide) → Double Helix (2 strands)

Question 10

Base Pairing + H-Bonds in DNA

Answer 10

Complementary base pairings (A-T (2 H-bonds) and C-G (3 H-bonds) ) are held together by H-bonds

Question 11

DNA Strands Direction

Answer 11

Antiparallel (5’ → 3’)

Question 12

Antiparallel

Answer 12

2 strands run in opposite directions (5’ → 3’)

Question 13

5’ End

Answer 13

Has phosphate group

Question 14

3’ End

Answer 14

Has free hydroxyl (-OH) group

Question 15

Nitrogenous Bases of DNA

Answer 15

Purines vs. Pyrimidines; Base pairing matches 1 purine with 1 pyrimidine → Consistent DNA width

Question 16

Purines

Answer 16

Double-ring structure: Adenine + Guanine

Question 17

Pyrimidines

Answer 17

Single-ring structure: Cytosine + Thymine

Question 18

DNA Method to Store Information (Genetic Code)

Answer 18

DNA = Biological code written using 4 nitrogen bases (A, T, C, G) → Sequence of bases stores genetic info → Sequence → Proteins → Traits

Question 19

DNA Replication

Answer 19

Base pairing rules allow accurate DNA copying; Produces 2 identical
molecules; Semi-Conservative

Question 20

Semi-Conservative Replication

Answer 20

Each new DNA molecule contains 1 parental strand + 1 new strand

Question 21

DNA Replication Starting Location

Answer 21

Multiple locations among each pair of strands - both directions from each origin → Many copies produced

Question 22

Characteristics that allow DNA to be copied

Answer 22

H-bonds easy to break → Unzip DNA

Question 23

DNA Synthesis

Answer 23

Can only be synthesized 5’ → 3’

Question 24

DNA Polymerase

Answer 24

Enzyme that synthesizes DNA; Read template 3’ → 5’; Synthesizes new strand 5’ → 3’

Question 25

DNA Strands

Answer 25

1 is continuous; Other is discontinuous

Question 26

Leading Strand

Answer 26

Synthesized toward the fork; Continuous strand

Question 27

Lagging Strand

Answer 27

Synthesized away from the fork; Discontinuous strand; Made of Okazaki fragments

Question 28

Replication Fork

Answer 28

Y-shaped structure formed during DNA replication where double-stranded DNA helix unwound + separate into single strands

Question 29

Okazaki Fragments

Answer 29

Short + newly synthesized DNA segments formed discontinuously on lagging strand during DNA replication

Question 30

RNA Primer

Answer 30

Needed to start DNA polymerase; Binding site for DNA polymerase to initiate DNA replication

Question 31

DNA Replication Key Enzymes Order

Answer 31

Helicase → SSB Proteins → Primase → DNA Polymerase → DNA Ligase

Question 32

Helicase

Answer 32

Breaks H-bonds → Unzips / unwinds DNA → Single-stranded DNA templates

Question 33

SSB Proteins

Answer 33

Keep strands separated + stable

Question 34

Primase

Answer 34

Builds RNA primer (starting point for DNA synthesis)

Question 35

DNA Polymerase

Answer 35

Adds nucleotides in the 5’ → 3’ direction to template; DNA repair + fix mistakes; Remove RNA primers + replace them with DNA nucleotides

Question 36

DNA Ligase

Answer 36

Join / seals gaps between Okazaki fragments

Question 37

Enzymes in DNA Replication

Answer 37

All work together at the replication fork

Question 38

DNA Replication Steps

Answer 38

Double helix unwinds (Helicase) + stays separate (SSB proteins) → Synthesis of Leading/Lagging Strand

Question 39

Synthesis of Leading Strand

Answer 39

Builds RNA primer (Primase) → Add nucleotides to template (DNA Polymerase) → Replace RNA primer with DNA (DNA Polymerase)

Question 40

Synthesis of Lagging Strand

Answer 40

Builds RNA primer for Okazaki fragment (Primase) → Add nucleotides to fragment (DNA Polymerase) → Replace RNA primer with DNA (DNA Polymerase) → Join fragments (Ligase)

Question 41

PCR