Chapter 33: The Structure of Informational Macromolecules - DNA and RNA (Test 1) Flashcards
What is the primary structure?
- The amino acid sequence
What is secondary structure?
- The 3D structure
What is tertiary structure?
- Supercoiling
What is quaternary structure?
- The interaction between DNA and proteins
How does DNA differ from RNA?
- DNA has a hydrogen at the 2’
- Contains thymine instead of uracil
Which bases are purines?
- Adenine
- Guanine
Which bases are pyrimidines?
- Cytosine
- Thymine (DNA)
- Uracil (RNA)
What is a nucleotide?
- A nucleoside with one or more phosphoryl groups attached
What stabilizes the helix?
- Hydrogen bonds between base pairs
- Hydrophobic interactions (stacking forces) between adjacent bases
What is reannealing?
- When 2 separated strands bind to one another
The helix is called the ___ form or the ___ helix
- B form; Watson-Crick
What accounts for DNA compaction
- Supercoiling
- The binding of certain proteins to DNA
What is the name of the entire complement of a cell’s DNA and its associated proteins?
- Chromatin
What comprises a nucleosome?
- Two copies of histones H2A, H2B, H3, H4, and 200 bp of DNA (a tetramer of (H3)2(H4)2 and a pair of (H2A-H2B) dimers)
- H1 binds to linker DNA
What is the stem-loop?
- A common structural motif seen in nucleic acids, especially RNA, when complementary sequences in the same strand form a helix
What is the purpose of small nuclear RNA?
- Process initial mRNA to its mature form in eukaryotes
What is the purpose of small interfering RNA?
- Affects gene expression
- Knock out genes
What is the purpose of micro RNA?
- Affects gene expression
- Important in growth and development
