Unit 1: Human Cells - Key Area 3 - Gene expression Flashcards
What is RNA?
A nucleic acid with a similar structure to DNA.
What are the three types of RNA?
- Messenger RNA (mRNA)
- Transfer RNA (tRNA)
- Ribosomal RNA (rRNA)
What is the function of transfer RNA?
Picks up a SPECIFIC amino acid from the cytoplasm and brings it to the ribosome.
What is the function of messenger RNA?
Carries the genetic code from the nucleus to the ribosome.
What is the function of ribosomal RNA?
Along with protein, it gives structure to the ribosome.
Where is mRNA made?
In the nucleus.
When is mRNA’s function used?
The first stage of protein synthesis.
When is tRNA’s function used?
The second stage of protein synthesis.
What does RNA consist of?
Nucleotides.
In RNA what are the four types of bases?
Adenine, cytosine, guanine, and uracil replaces thymine.
What is the complementary base pair for adenine in RNA?
Uracil.
How are proteins made?
Proteins are made by joining together amino acids in a specific sequence.
What does the protein produced by protein synthesis rely on?
The order of amino acids which is dictated by the order/sequence of the bases on the DNA.
What are the two main stages of protein synthesis?
Transcription and Translation.
What are the stages of transcription?
- The section of DNA which codes for the desired protein unwinds and unzips. This is carried out by an enzyme called RNA polymerase.
- Free RNA nucleotides enter the nucleus and RNA POLYMERASE joins them with their complementary DNA base starting at the 3’ end.
- Only one strand is copied.
What is the strand of mRNA produced by transcription called?
The Primary Transcript.