dna and rna Flashcards
(27 cards)
What are nucleic acids made up of?
Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), and Phosphorus (P).
What are the monomers of nucleic acids?
Nucleotides.
What are the components of a nucleotide?
Pentose sugar (5-carbon sugar), organic nitrogen base, and phosphate group.
What is the structure of DNA?
Double-Stranded with a double helical structure.
What is the structure of RNA?
Single-Stranded with a linear structure.
What nitrogen base is found in DNA?
Thymine (T).
What nitrogen base is found in RNA?
Uracil (U).
What are polynucleotides?
Many nucleotides linked together into a long chain, forming DNA or RNA.
What bonds are formed between nucleotides in polynucleotides?
Phosphodiester bonds formed by condensation reactions between the sugar of one nucleotide and the phosphate group of the next nucleotide
What is the nature of the genetic code?
The genetic code is based on triplets of bases (codons). There are 4 nitrogen bases (A, T, C, G) and 20 amino acids. A minimum of 3 bases are needed to code for one amino acid.
What does non-overlapping mean in the context of codons?
Codons are read sequentially in groups of 3, without overlap. For example, the sequence AGGTCA is read as AGG and TCA, not as AGG, GGT, GTC, TCA.
What is degeneracy in the genetic code?
Multiple codons can code for the same amino acid. This redundancy helps protect against mutations.
What is a gene?
A segment of DNA that codes for a specific protein, which in turn controls a trait or characteristic in an organism.
What is a codon?
A sequence of 3 bases (nucleotides) in DNA or mRNA that codes for a specific amino acid.
What is the antisense strand?
The DNA strand that acts as the template for mRNA synthesis. It is complementary to the mRNA strand.
What is the first step in the protein synthesis process?
Transcription (DNA → mRNA): DNA Helicase unwinds the DNA, breaking the hydrogen bonds between the bases.
What role does RNA Polymerase play in transcription?
RNA Polymerase catalyzes the formation of phosphodiester bonds between RNA nucleotides.
What binds to a ribosome in the cytoplasm?
mRNA binds to a ribosome in the cytoplasm.
What do tRNA molecules bring to the ribosome?
tRNA (transfer RNA) molecules bring amino acids to the ribosome.
What does each tRNA molecule have?
Each tRNA has an anticodon that is complementary to the codon on the mRNA and an amino acid attached to the other end.
What is the complementary anticodon for the start codon AUG?
The complementary anticodon UAC on the tRNA binds to AUG on the mRNA.
What happens after the first tRNA molecule attaches to the start codon?
The second tRNA molecule attaches to the next codon on the mRNA, bringing the corresponding amino acid.
What is formed between the amino acids during translation?
Peptide bonds are formed between the amino acids, creating a polypeptide chain.
What happens to the first tRNA after it leaves its amino acid?
The first tRNA detaches from the mRNA, leaving behind its amino acid.
