Nucleic Acids - AP Biology
- What are the two types of nucleic acids?
- DNA and RNA. The two major classes of nucleic acids found in living organisms.
- What base does cytosine pair with?
- Guanine. G-C base pairs form three hydrogen bonds in both DNA and RNA.
- What is exonuclease activity?
- Removes nucleotides from ends of DNA. Proofreads and removes incorrect nucleotides during replication.
- Which RNA carries amino acids to ribosomes?
- tRNA (transfer RNA). Delivers specific amino acids during protein synthesis.
- Which enzyme synthesizes RNA from a DNA template?
- RNA polymerase. Catalyzes the formation of RNA during transcription.
- What is the function of topoisomerase?
- Relieves strain in DNA ahead of replication fork. Prevents overwinding that would halt replication.
- What is the central dogma of molecular biology?
- DNA → RNA → Protein. Describes the flow of genetic information in cells.
- What is the function of DNA polymerase?
- Synthesizes new DNA strands. Adds nucleotides to growing DNA strand during replication.
- What is the main difference between RNA and DNA bases?
- RNA contains uracil; DNA contains thymine. RNA substitutes uracil for thymine found in DNA.
- What is the structure of DNA?
- Double helix. Two antiparallel strands twisted around each other.
- What is the function of primase?
- Synthesizes RNA primers. Creates short RNA sequences needed to start DNA synthesis.
- What base does adenine pair with in RNA?
- Uracil. RNA uses uracil instead of thymine for pairing with adenine.
- What is the process of synthesizing RNA from DNA called?
- Transcription. The first step in gene expression from DNA to protein.
- What is complementary base pairing?
- A pairs with T/U; G pairs with C. Ensures accurate DNA replication and RNA transcription.
- What is a ribozyme?
- Catalytic RNA molecule. RNA with enzymatic activity, like ribosomal peptidyl transferase.
- Which nitrogenous bases are pyrimidines?
- Cytosine, Thymine, and Uracil. Pyrimidines have single-ring structures with six atoms.
- What is the sugar found in DNA?
- Deoxyribose. Deoxyribose lacks the 2' hydroxyl group found in ribose.
- What is a mutation?
- A change in the DNA sequence. Can be beneficial, neutral, or harmful to an organism.
- Which nitrogenous bases are purines?
- Adenine and Guanine. Purines have two-ring structures with nine atoms.
- What is the structure of RNA?
- Single-stranded. RNA typically exists as a single chain of nucleotides.
- What is the role of ligase in DNA replication?
- Joins Okazaki fragments. Seals gaps between DNA fragments on the lagging strand.
- What is the process of synthesizing proteins from RNA called?
- Translation. The final step converting mRNA sequence into protein sequence.
- What is the function of snRNPs?
- Involved in RNA splicing. Small nuclear ribonucleoproteins process pre-mRNA.
- What is a gene?
- A segment of DNA coding for a protein. Contains instructions for making a specific protein.
- What is the function of helicase in DNA replication?
- Unzips the DNA helix. Breaks hydrogen bonds between base pairs to separate strands.
- What is the process of copying DNA called?
- DNA replication. Creates identical copies of DNA for cell division.
- What is the sugar found in RNA?
- Ribose. Ribose has a hydroxyl group on the 2' carbon that DNA lacks.
- Which nitrogenous base pairs are stronger?
- G-C pairs (three hydrogen bonds). More hydrogen bonds make G-C pairs more stable than A-T.
- Which RNA carries genetic information from DNA?
- mRNA (messenger RNA). Carries genetic instructions from nucleus to ribosomes.
- Which enzyme removes RNA primers during replication?
- DNA polymerase I. Has 5' to 3' exonuclease activity to remove primers.
- What type of bond holds base pairs together?
- Hydrogen bonds. Weak bonds that allow DNA strands to separate during replication.
- Which RNA forms the core of ribosomes?
- rRNA (ribosomal RNA). Structural and catalytic component of protein synthesis machinery.
- What base does adenine pair with in DNA?
- Thymine. A-T base pairs form two hydrogen bonds in DNA.
- What is a nucleotide composed of?
- Sugar, phosphate group, nitrogenous base. The basic building block of nucleic acids.
- What is the primary function of DNA?
- Storing genetic information. DNA serves as the hereditary material in most organisms.
- What is an anticodon?
- A trinucleotide sequence on tRNA. Complementary sequence that pairs with mRNA codons.
- What is the role of telomerase?
- Extends telomeres. Prevents chromosome shortening during DNA replication.
- What is the role of a codon?
- Specifies an amino acid. Three-nucleotide sequence that codes for one amino acid.
- What is a nucleosome?
- DNA wrapped around histone proteins. Basic unit of chromatin packaging in eukaryotes.