DNA Replication

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Replication Noun

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[rep-li-kay-shun]

Back

Replication

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The biological process of producing two identical replicas of DNA from one original DNA molecule before cell division occurs.

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Example: This diagram shows how a DNA molecule 'unzips' and each original strand is used as a template to build a new, matching strand, creating two identical DNA copies.

Front

Base Pairing Noun

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[bays pair-ing]

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Base Pairing

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The principle dictating how nitrogenous bases in DNA bond: adenine with thymine, and guanine with cytosine.

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Example: This image shows how in a DNA molecule, specific nitrogenous bases pair up: Guanine (G) with Cytosine (C), and Adenine (A) with Thymine (T).

Front

Complementary Strands Noun

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[kom-pluh-men-tuh-ree strands]

Back

Complementary Strands

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The two strands of a DNA molecule where each strand can be used as a template to reconstruct the other.

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Example: The two strands of DNA are complementary because the bases follow a pairing rule: Adenine (A) always pairs with Thymine (T), and Guanine (G) always pairs with Cytosine (C).

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S Phase Noun

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[es fayz]

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S Phase

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The specific phase of the cell cycle during which the cell's DNA is synthesized and replicated.

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Example: During the S phase of the cell cycle, each chromosome is duplicated. This process creates an identical copy, resulting in two sister chromatids joined together.

Front

Semiconservative Replication Noun

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[sem-ee-kun-sur-vuh-tiv rep-li-kay-shun]

Back

Semiconservative Replication

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The replication model where each new DNA molecule consists of one original strand and one newly synthesized strand.

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Example: This diagram shows semiconservative replication, where an original DNA molecule separates, and each original strand (blue) is used as a template to create a new complementary strand (pink).

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Hydrogen Bonds Noun

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[hy-druh-jen bonds]

Back

Hydrogen Bonds

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The weak chemical bonds between base pairs that are broken to unwind the DNA double helix during replication.

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Example: This diagram shows how weak hydrogen bonds hold DNA base pairs together: two bonds connect adenine (A) and thymine (T), and three bonds connect guanine (G) and cytosine (C).

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Template Strand Noun

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[tem-plit strand]

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Template Strand

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An original strand of DNA that serves as a model or guide for the synthesis of a new, complementary strand.

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Example: The image shows the 'old DNA strand' acting as a template, or pattern, for building a 'new DNA strand' during DNA replication.

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Replication Fork Noun

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[rep-li-kay-shun fork]

Back

Replication Fork

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The Y-shaped region on a replicating DNA molecule where the two strands of the double helix separate.

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Example: This diagram shows how a DNA molecule 'unzips' to form a replication fork, creating a leading strand and a lagging strand for copying.

Front

DNA Polymerase Noun

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[dee-en-ay pol-uh-muh-rays]

Back

DNA Polymerase

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The principal enzyme that joins individual nucleotides to produce a new DNA strand and also proofreads the new strand.

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Example: This diagram shows the enzyme DNA polymerase moving along an old DNA strand to build a new, complementary strand by adding matching bases.

Front

Proofreading Noun

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[proof-reed-ing]

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Proofreading

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The process by which DNA polymerase checks and corrects errors in the newly synthesized DNA strand to ensure accuracy.

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Example: During DNA replication, the enzyme DNA polymerase checks for errors. If it finds a mismatched base, it removes and replaces it, ensuring accuracy.