U3 DNA protein synthesis Flashcards
what is replication?
- copy DNA by pulling strands apart, create new complementary strand for each single strand
- must occur before cell division
- occurs during interphase of cell cycle
What is the first step of DNA replication?
- enzyme helicase breaks the hydrogen bonds and unwinds the double helix forming two parental strands
What is the second step of DNA replication?
- enzyme DNA polymerase matches free nucleotides to their complementary bases, forming new daughter strands
What is the third step of DNA replication?
- DNA polymerase bonds nucleotides together, forming two identical copies of the original double helix
what is semi-conservation?
- each new DNA molecule is half daughter strand half parental strand
- each old strand serves as a template for a new complementary strand
Recombinant DNA?
synthetic DNA created by combining DNA from other organism
3 practical uses of recombinant DNA?
- insert human genes into bacteria to mass produce useful molecules (insulin)
- insert pest resistance into crops
- inserting genes into animals yo make them grow larger, or produce drugs in their milk
What is protein synthesis?
- sequence of DNA that codes for synthetic protein
- protein synthesis occurs in, and out of the nucleus. RNA carries info from the DNA to the ribosomes
order of steps in protein synthesis?
DNA-transcription-mRNA-translation-PROTEIN
What are the two processes DNA must undergo to be converted into a protein?
transcription-DNA is copied into mRNA in the nucleus
translation-mRNA instructions are “read” to form protein at the ribosome
What three streps follow the process of transcription, and translation?
initiation, elongation, termination
Explain the steps of Transcription
- initiation-enzyme RNA polymerase unzips the double helix and attaches to a region at the start of the gene
- elongation-RNA polymerase matches complementary RNA nucleotides to the template strand, forming mRNA
- termination-RNA polymerase reaches region at the end of gene, stops transcribing and the mRNA strand is released
what is mRNA? messenger RNA
- carries gene information out of the nucleus to the ribosome
- made up of codons (triplets of three bases)
what is a codon?
- sequence of three DNA or RNA nucleotides
- corresponds to a specific amino acid
start codon and stop codons?
- AUG (start codon, amino acid methionine)
- UAA, UAG, UGA (stop codon, stops translation)