DNA Structure and Replication

This set of flashcards covers key concepts about the structure and replication of DNA.

The basic building blocks of DNA are __.

Nucleotides

DNA has a __ structure characterized by two strands coiled around each other.

double helix

__ bond holds the sugar-phosphate backbone together.

Covalent

Adenine pairs with __ in DNA structure.

Thymine

The difference between purines and pyrimidines is that purines have fused rings, while pyrimidines have ring.

two; one

The ends of DNA molecules are referred to as and ends.

5'; 3'.

In DNA replication, __ unwinds the DNA strands by breaking hydrogen bonds.

Helicase

The __ adds new DNA nucleotides complementary to the template strand.

DNA polymerase

Okazaki fragments are associated with the __ strand during DNA replication.

lagging

The __ formed during DNA replication ensures the copying of DNA in the 5' to 3' direction.

leading strand

Telomeres are located at the __ of chromosomes.

ends

Erwin Chargaff's rule states that the amount of equals the amount of in DNA.

adenine; thymine

and used X-ray diffraction to determine that DNA had a double helix structure.

Wilkins; Franklin

DNA replication is described as __ because each new double helix has one original strand and one new strand.

semi-conservative

In eukaryotes, DNA replication begins at multiple __ along the DNA molecule.

origins

What is transcription?

Transcription is the process by which the DNA sequence of a gene is copied into a complementary RNA sequence.

What is transcription?

Transcription is the cellular process in which the information encoded in a specific segment of DNA is transcribed into a messenger RNA (mRNA) molecule. This process involves several key steps including initiation, elongation, and termination, and is crucial for protein synthesis.

What are the key enzymes involved in transcription?

The main enzyme involved in transcription is RNA polymerase. This enzyme binds to the DNA template and synthesizes the RNA strand by adding ribonucleotides in a sequence complementary to the DNA template. Other factors, such as transcription factors, are also important for the initiation of transcription by helping RNA polymerase bind to the promoter region of the gene.