Gene Expression Flashcards
What is the meaning of gene expression? How might genes be influenced?
When information from a gene is used to produce a protein (or other product).
Gene expression can be influenced by external factors, such as the environment, or internal factors, such as hormones and metabolism.
What are the key steps involved in protein synthesis?
Transcription:
1. RNA polymerase unwinds and copies the DNA code’s template strand.
2. Complementary free nucleotides form the mRNA strand (T is replaced with U).
3. mRNA leaves the nucleus via nuclear pore, DNA reforms double helix.
Translation:
1. mRNA strand attaches to the nucleus, ribosome reads it one codon at a time.
2. Complementary tRNA containing an anti-codon collects correct amino acid from the cytoplasm.
3. tRNA brings the amino acid back to the ribosome.
4. Ribosome assembles amino acids and binds them with a peptide bond, forming a protein.
What is the role of DNA?
Stores genetic material, ie. instructions on how to make proteins.
What is the role of RNA polymerase?
Unwinds and copies DNA template strand to make mRNA.
What is the role of mRNA?
Delivers instructions for proteins from nucleus to ribosomes.
What is the role of tRNA?
Collects amino acids and delivers them to the ribosomes.
What is the role of amino acids?
Form the protein.
