AP Biology Flashcards: Dna Replication

What this deck covers

This deck focuses on Dna Replication, giving you a quick way to review the definitions, rules, and examples that matter most for AP Biology.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What is the function of the sliding clamp in DNA replication?

Answer: Increases processivity of DNA polymerase. Keeps polymerase attached for longer synthesis periods.

Flashcard 2: What prevents the re-annealing of DNA strands during replication?

Answer: Single-strand binding proteins. Coat separated strands to maintain single-strand state.

Flashcard 3: What is the role of exonuclease in DNA replication?

Answer: Removes mismatched nucleotides. Ensures accuracy by removing incorrectly paired bases.

Flashcard 4: Identify the enzyme that initiates the unwinding of DNA.

Answer: Helicase. Motor protein that moves along DNA breaking base pairs.

Flashcard 5: What is the role of telomerase in DNA replication?

Answer: Extends telomeres in eukaryotic cells. Solves the end-replication problem at chromosome tips.

Flashcard 6: Identify the function of single-strand binding proteins in replication.

Answer: Stabilize unwound DNA strands. Prevent secondary structure formation in exposed DNA.

Flashcard 7: Identify the strand synthesized discontinuously during DNA replication.

Answer: Lagging strand. Synthesized away from the replication fork direction.

Flashcard 8: What is the replication fork?

Answer: Y-shaped region where new DNA strands are synthesized. Site of active DNA synthesis with exposed template strands.

Flashcard 9: What is the function of primase in DNA replication?

Answer: Synthesizes RNA primers. DNA polymerase requires a primer with a 3'-OH group to start.

Flashcard 10: What is the replication fork?

Answer: Y-shaped region where new DNA strands are synthesized. Site of active DNA synthesis with exposed template strands.

Flashcard 11: What is the primary enzyme responsible for synthesizing new DNA strands?

Answer: DNA polymerase. This enzyme can add nucleotides to existing 3'-OH groups.

Flashcard 12: What ensures the fidelity of DNA replication?

Answer: Proofreading by DNA polymerase. 3' to 5' exonuclease activity removes incorrect nucleotides.

Flashcard 13: What characterizes the lagging strand synthesis?

Answer: Occurs in short Okazaki fragments. Synthesis occurs in segments due to 5' to 3' directionality.

Flashcard 14: Which nucleotide pairs with adenine during DNA replication?

Answer: Thymine. Complementary base pairing follows Watson-Crick rules.

Flashcard 15: Which protein complex aids in the loading of DNA polymerase?

Answer: Clamp loader. Positions sliding clamp around DNA for processivity.

Flashcard 16: Which protein complex aids in the loading of DNA polymerase?

Answer: Clamp loader. Positions sliding clamp around DNA for processivity.

Flashcard 17: Identify the strand synthesized discontinuously during DNA replication.

Answer: Lagging strand. Synthesized away from the replication fork direction.

Flashcard 18: Which enzyme catalyzes the formation of phosphodiester bonds in DNA?

Answer: DNA ligase. Creates covalent bonds linking DNA backbone segments.

Flashcard 19: What is the role of exonuclease in DNA replication?

Answer: Removes mismatched nucleotides. Ensures accuracy by removing incorrectly paired bases.

Flashcard 20: Which nucleotide pairs with adenine during DNA replication?

Answer: Thymine. Complementary base pairing follows Watson-Crick rules.

Flashcard 21: Which enzyme removes RNA primers during DNA replication?

Answer: DNA polymerase I. Has 5' to 3' exonuclease activity for primer removal.

Flashcard 22: Identify the direction of the template strand for leading-strand synthesis.

Answer: 3' to 5' direction. Template runs antiparallel to the synthesis direction.

Flashcard 23: Identify the short sequences of RNA that initiate DNA synthesis.

Answer: RNA primers. Provide the 3'-OH group needed for DNA polymerase initiation.

Flashcard 24: What is the function of DNA ligase in DNA replication?

Answer: Joins Okazaki fragments. Forms phosphodiester bonds between adjacent DNA segments.

Flashcard 25: What is the primary enzyme responsible for synthesizing new DNA strands?

Answer: DNA polymerase. This enzyme can add nucleotides to existing 3'-OH groups.

Flashcard 26: Identify the direction of the template strand for leading-strand synthesis.

Answer: 3' to 5' direction. Template runs antiparallel to the synthesis direction.

Flashcard 27: Identify the phase of the cell cycle in which DNA replication occurs.

Answer: S phase. Synthesis phase when DNA content doubles in the cell.

Flashcard 28: What is the template strand in DNA replication?

Answer: The original DNA strand used for synthesis. Provides the sequence information for new strand synthesis.

Flashcard 29: What are the short DNA fragments synthesized on the lagging strand called?

Answer: Okazaki fragments. Result from discontinuous synthesis on the lagging strand.

Flashcard 30: What prevents the re-annealing of DNA strands during replication?

Answer: Single-strand binding proteins. Coat separated strands to maintain single-strand state.

Flashcard 31: What is required for DNA polymerase to begin synthesis?

Answer: RNA primer. DNA polymerase cannot initiate synthesis de novo.

Flashcard 32: Which enzyme relieves the strain of unwinding DNA during replication?

Answer: Topoisomerase. Prevents excessive supercoiling ahead of the replication fork.

Flashcard 33: Identify the nucleotide that pairs with cytosine in DNA.

Answer: Guanine. Forms three hydrogen bonds with cytosine in base pairs.

Flashcard 34: What is the origin of replication?

Answer: Specific sequence where replication begins. Recognized by initiator proteins to start replication.

Flashcard 35: What is the role of telomerase in DNA replication?

Answer: Extends telomeres in eukaryotic cells. Solves the end-replication problem at chromosome tips.

Flashcard 36: What is the function of the sliding clamp in DNA replication?

Answer: Increases processivity of DNA polymerase. Keeps polymerase attached for longer synthesis periods.

Flashcard 37: What is the function of DNA ligase in DNA replication?

Answer: Joins Okazaki fragments. Forms phosphodiester bonds between adjacent DNA segments.

Flashcard 38: Which molecule provides the energy for DNA polymerization?

Answer: Deoxyribonucleoside triphosphates (dNTPs). Release of pyrophosphate drives the polymerization reaction.

Flashcard 39: Which strand is synthesized continuously during DNA replication?

Answer: Leading strand. Synthesized continuously in the 5' to 3' direction.

Flashcard 40: Which enzyme synthesizes the new strand by adding nucleotides?

Answer: DNA polymerase. Main replicative enzyme that extends DNA chains.

Flashcard 41: What characterizes the lagging strand synthesis?

Answer: Occurs in short Okazaki fragments. Synthesis occurs in segments due to 5' to 3' directionality.

Flashcard 42: Identify the enzyme that initiates the unwinding of DNA.

Answer: Helicase. Motor protein that moves along DNA breaking base pairs.

Flashcard 43: What ensures the fidelity of DNA replication?

Answer: Proofreading by DNA polymerase. 3' to 5' exonuclease activity removes incorrect nucleotides.

Flashcard 44: What is the role of helicase in DNA replication?

Answer: Unwinds the DNA double helix. Breaks hydrogen bonds between complementary base pairs.

Flashcard 45: What does semiconservative replication mean?

Answer: Each new DNA molecule has one old and one new strand. One parental strand is conserved in each new molecule.

Flashcard 46: Identify the function of single-strand binding proteins in replication.

Answer: Stabilize unwound DNA strands. Prevent secondary structure formation in exposed DNA.

Flashcard 47: Which molecule provides the energy for DNA polymerization?

Answer: Deoxyribonucleoside triphosphates (dNTPs). Release of pyrophosphate drives the polymerization reaction.

Flashcard 48: What does semiconservative replication mean?

Answer: Each new DNA molecule has one old and one new strand. One parental strand is conserved in each new molecule.

Flashcard 49: What is the template strand in DNA replication?

Answer: The original DNA strand used for synthesis. Provides the sequence information for new strand synthesis.

Flashcard 50: Identify the enzyme that corrects supercoiling during replication.

Answer: Topoisomerase. Relieves tension from unwinding by creating temporary breaks.

Flashcard 51: Identify the direction in which DNA polymerase synthesizes new DNA.

Answer: 5' to 3' direction. DNA polymerase can only add nucleotides to the 3' end.