Chapter 4 Nucleic Acids and Info Flow

What did F. Griffith’s experiment in 1928 show about DNA?

That it is made of genetic material, specifically he only found that some type of molecule in the debris carried the genetic information for virulence, but he did not identify this molecule.

What is true about all [nucleotide]ase and their corresponding chemical bonder? (DNase, RNAse, Protease)?

They are degrading enzymes that chew up their respective molecules.

What did Avery, Macleod, and McCarty’s Experiment find out?

That the molecule that F. Griffith could not identify turned about to be DNA, and they also found out that DNA is considered to be a “transformative substance”.

What will DNA always be comprised of?

A phosphate group (ionized)

A deoxyribose sugar

A Base ( Adenine, Guanine, Thymine, or Cytosine)

A phosphate group

What is true about the structure of a molecule if the 2nd carbon group has a hydroxyl group?

The molecule is RNA.

What is true about the structure of a molecule if the 2nd carbon group (Going clockwise) has only a hydrogen?

The molecule is DNA.

What are the two groups that the four bases of DNA fall under?

Purines (double-ringed structures), Pyrimidines (Single-ringed structures)

What are the purines of DNA?

Adenine and Guanine

What are the Pyrimidines of DNA?

Thymine and Cytosine

What does a nucleoside comprise of?

A sugar and a base

What does a nucleotide comprise of?

A nucleoside with one or more phosphate groups

How are nucleotide sequences read?

5’-3’, reflecting the polarity of the strand.

What does adenine pair up with in DNA strands?

Thymine, always.

What does guanine pair up with in DNA stands?

Cytosine, always.

When a DNA strand goes through transcription to RNA, what are the rules to create a corresponding sequence?

All bases pair the same, except Adenine now pairs with uracil.

Between base pairs, what type of bonds connect them?

Hydrogen bonds

Adenine and Thymine are held together by how many bonds?

Double hydrogen bonds.

Guanine and Cytosine are held together by how many bonds?

Triple hydrogen bonds.

What type of bonds contribute to the stability of DNA?

Hydrogen bonds between bases on opposite strands.

What are interactions between bases on the same strand called?

Base stacking.

What is DNA replication?

Preserving the sequence of DNA, complementary base pairing ensures the fidelity of DNA replication.

What are nucleosomes?

The main packaging mechanism for eukaryotic DNA. Made up of 8 protein subunits, acting like a ‘spool’ for the DNA thread.

What are histones?

The proteins of nucleosomes.