Biology DNA

What is DNA?

A nucleic acid made up of a string of nucleotides

Summarize the rules of Chargaff's double helix

Adenine and Thymine are complementary bases Two hydrogen bonds join A=T Guanine and Cytosine are complementary bases Three hydrogen bonds join G-C

Name the specific sugar found in DNA. What kind of sugar is it?

Deoxyribose A five-carbon monsaccharide (pentose)

What are the two groups of nitrogenous bases?

the pyrimidines, which have a single ring the purines, which have two rings

How many rings does purines group have?

two

List the complementary base-pairing found in DNA and include the number of hydrogen bonds between them

Guanine and Cytosine bond with three hydrogen bonds Adenine and Thymine bond with two hydrogen bonds

Why is it relatively easy for two stands of DNA molecule to come apart so that they can participate in DNA synthesis (replication)?

Hydrogen bonds are weak and can be broken easily

What are nucleotides?

Monomers of nucleic acids

What nitrogenous base is found in RNA?

Uracil (U) in place of Thymine, which is not found in RNA

What is a phosphodiester linkage?

a series of bonds connecting two or more molecules: C-O-P-O-C Covalent bonds that bind each phosphate group to two different sugar molecules: one phosphate end forms a phosphodiester linkage with the 5' carbon atom of a sugar located below, while the other phosphate end links to the 3' carbon of the sugar above it.

How many rings does the pyrimidines group have?

one

How many restriction enzymes are typically needed to positively identify a sample of DNA?

10-12

What three components make up nucleotides?

1) a phosphate group 2) a pentose or five-carbon sugar 3) one of the nitrogenous bases (each base consists of one or two rings that contain nitrogen)

What are the five nitrogenous bases?

Adenine (A) Guanine (G) Thymine (T) Cytosine (C) which occurs in DNA Uracil (U) which is not found in DNA

What are the two purine bases found in DNA?

Adenine and Guanine

DNA polymerase "knows" which bases to put on the new strands of DNA based on:

Complementary Base pairs 2 hydrogen bonds vs. 3 hydrogen bonds 3 rings required (purines bonded with pyrimidines

What are the two pyrimidine bases found in DNA?

Cytosine and Thymine

What molecule fits into the active site of a restriction enzyme?

DNA

How does the sugar found in DNA differ from that found in RNA?

DNA lacks one oxygen atom at the 2' carbon RNA has one oxygen atom at the 2'carbon