Chapter 25: DNA Structure and DNA Replication Flashcards
What are the parts of a bacteriophage?
- head
- DNA
- neck
- collar
- sheath
- tail fiber
- base plate
What is the structure of a DNA molecule?
- phosphate
- sugar
- nitrogenous base
What is the structure of a molecule?
- phosphate
- deoxyribose sugar
- base
What do hydrogen bonds do?
hold the 2 strands of DNA together
What do covalent bonds do?
hold the bases, sugars, and phosphate groups together
What did Rosalind Franklin do?
used X-ray diffraction to get information about the structure of DNA
What did Hershey-Chase do?
confirm that DNA causes transformations by using bacteriophages–injected a radioactive protein marker into DNA to see how it would react
What is Chargaff’s rule?
complementary base-pairing:
adenine(A) = thymine(T);
cytosine(C) = guanine(G)
What is the process of DNA replication?
- DNA helicase “unzips” the molecule by breaking the hydrogen bonds that hold the strands together and unwind it
- ligands attach to keep the hydrogen bonds from going back together
- DNA polymerase joins nucleotides using the original strand as a template and spell checks for errors
- DNA polymerase 1 puts down the leading strand
- the leading strand adds bases continuously for the section
- the lagging strand forms Okazaki fragments
- single strand RNA polymerase creates a primer for a DNA polymerase base for the leading and lagging strand and continues (DNA polymerase 1 replaces the primer with DNA nucleotides)
- copying happens in opposite directions along the 2 strands and in multiple places at once
What would the complementary base-pairing be in DNA replication?
- A = T
- T = A
- C = G
- G = C
What is the resulting product of DNA replication?
a DNA molecule that has half the original strand and half of the new strand
