A1.2.4 Bases in each nucleic acid that form the basis of a code Flashcards
Name the purines found in nucleic acids.
Adenine (A) and Guanine (G).
What are the pyrimidines found in DNA and RNA?
Cytosine (C), Thymine (T) in DNA, and Uracil (U) in RNA.
What is meant by codon redundancy?
Multiple codons can code for the same amino acid.
What is a reading frame in genetics?
The way bases are read in groups of three, starting at the correct position.
What is the base pairing rule for adenine in DNA?
Adenine (A) pairs with Thymine (T) through 2 hydrogen bonds.
What is a key feature of the genetic code regarding codons?
The genetic code is non-overlapping; each base belongs to only one codon.
What does the mRNA sequence AUG-CCG-UAC represent?
It represents three codons: AUG (Start/Methionine), CCG (Proline), UAC (Tyrosine).
What are the three stop codons?
UAA (Ochre), UAG (Amber), UGA (Opal).
What is a frameshift mutation?
A shift in the reading frame that alters the amino acid sequence.
What is the primary start codon?
AUG, which codes for methionine.
What is the function of the genetic code?
It allows for the storage and expression of genetic information.
What is a codon?
A triplet of bases that specifies an amino acid, a start signal, or a stop signal.
Why is the correct reading frame essential?
It is crucial for proper protein synthesis.
What is the significance of stop codons?
They signal the end of protein synthesis.
How do hydrogen bonds contribute to base pairing?
A pairs with T/U through 2 hydrogen bonds, and G pairs with C through 3 hydrogen bonds.
What is the base pairing rule for guanine?
Guanine (G) pairs with Cytosine (C) through 3 hydrogen bonds.
What happens if the reading frame is shifted?
It completely changes the meaning of the sequence, leading to different codons.
What does it mean that the genetic code is universal?
The code is nearly identical in all living organisms, with the same codons specifying the same amino acids.
What are the two categories of nitrogenous bases in nucleic acids?
Purines and Pyrimidines.
