DNA to Protein Synthesis Quiz

DNA to Protein Synthesis

• DNA replication occurs in the nucleus.
• The process results in a new strand of DNA.
• DNA is unzipped.
• Nucleotide bases are added to the unzipped halves of the DNA strand.
• Thymine always pairs with adenine.
• Cytosine always pairs with guanine.
• This results in 2 identical DNA strands.
• DNA replication is different from cell division.

DNA Structure

• DNA resembles a twisted ladder.
• The rungs of the ladder are the nucleotide bases thymine, cytosine, guanine, and adenine.
• The sides of the ladder are the sugar-phosphate backbones.
• Thymine is always a nucleotide base.

Unidirectional Replication

• DNA is replicated in one direction.
• The enzymes involved in replication are DNA Polymerase, Helicase, Single-strand binding proteins, and Topoisomerase.
  • The process involves the replication of the lagging and leading strands of DNA.
  • The lagging strand needs Okazaki fragments to be assembled after replication with RNA primers.
• The enzyme, DNA primase, is involved in creating the RNA primer that DNA polymerase extends off of during replication.
• DNA ligase links to the Okazaki fragments to form a continuous strand.

Transcription

• Transcription occurs in the nucleus.
• DNA is unzipped.
• Nucleotides pair with the halves of the DNA.
• Uracil replaces thymine during this process.
• This creates mRNA.
• mRNA is the instruction for making proteins.
• mRNA is divided into groups of 3 nucleotides called codons that result in different amino acids being made.
• For example, GAU would result in the amino acid asparagine.

RNA Structure

• RNA resembles DNA.
• RNA is half of DNA.
• Thymine in RNA is replaced by uracil.
• Uracil pairs with adenine.

Types of RNA

• There are 3 types of RNA: mRNA, tRNA, and rRNA.
• mRNA acts as a template for making proteins.
• tRNA carries the amino acids to the ribosomes.
• rRNA assembles the protein using the amino acids brought by tRNA.

Translation

• Translation occurs on the ribosomes in the cytoplasm.
• Translation matches the codons of the mRNA with the ribosome.
• Once a stop codon is reached, the protein is complete.
• The 3 nucleotide bases of the mRNA codon will match a corresponding amino acid.
• Chains of amino acids are called polypeptides, which are proteins.

Gene Mutation

• Not all genes are expressed all the time.
• DNA can be transferred into protein.
• Gene mutations affect a single gene.
• Substitutions, insertions, or deletions can affect a gene.
• Insertions shift the strand one to the right while deletions shift the stand one to the left.
• Not all mutations are harmful.

Types of Mutations

• Point mutation affects one nucleotide.
• Frameshift mutation affects more than one nucleotide.
• Missense mutation changes an amino acid.
• Mutations can cause a protein to be made incorrectly or incompletely.
• Mutations can create a stop codon resulting in a premature stop of the gene being translated.
• Silent mutations have no significant effect.

Chromosomal Mutation

• Chromosomal mutations affect multiple genes.
• Types of chromosomal mutations include deletion, inversion, duplication, and translocation.
• Deletions remove a segment of DNA.
• Inversions switch segments of DNA.
• Duplications repeat a segment, and translocations move segments of chromosomes.

Causes of Mutation

• UV radiation from high sun exposure.
• Chemicals like nitrous acid.
• Mutations cause problems with genes regulating cell division (like cancer.)

Test your knowledge on the fundamentals of DNA replication and structure. This quiz covers key concepts such as nucleotide pairing, the role of various enzymes in replication, and the physical structure of DNA. Perfect for students learning about genetics and molecular biology.