3.5 Transcription & Translation

Question 0

I don’t like DNA transcription in terms of the formation of RNA strand complementary to the DNA strand by polymerase.

Answer 0

– Area beginning of where one gene is found is unzipped.

• One of the two strands antisense will be used as a template to create the M RNA.
• Are named Polly Merce moves along (antisense)acting as a catalyst which causes the RNA nucleotides to complementary bind (same as DNA except uracil)
• mRNA is created, it is a smaller strand than DNA and only the complimentary copy of one gene

Question 1

compare the structure of RNA and DNA.

Answer 1

DNA: double helix, ATCG, codes all, only in nucleus, deoxy ribose,DNA polymerase 1 one and DNA polymerase11 are the enzymes involved

RNA: single helix, AUCG (uracil), codes proteins, in Nucleus and cytoplasm, sugar ribose, enzyme involved- rna polymerase 1

Same: contains 5 carbon sugar, each nucleotide has 4 nitrogenous bases

Question 2

Describe the genetic code in terms of codons composed of triplets of basis.

Answer 2

• MRNA is complementary copy of one gene a DNA.
• Usually has enough info to make one polypeptide – amino acids serious
• message in written into mRNA determines the order of the amino acids.
• Researchers found genetic code written three bases.
• Everything he bases is enough info to code one amino acid.
• A set of 3 bases that determines one amino acid is called a triplet.
• When a triple is found on mRNA molecules it is called a codon or codon triplet.

Question 3

Explain the process of translation leading to polypeptide formation.

Answer 3

Translation process of photosynthesis where genetic information encoded in mRNA is translated into sequence of the new acids into a polypeptide chain.

Ribozymes buying to mRNA in the cells cytoplasm and move along the mRNA molecule in the 5 to 3 direction until it reaches the start codon AUG.

Anti-codons on and on tRNA molecules ally opposite appropriate: according to complementary base pairing.

Each tRNA molecule cases this is the Camino acid going to the genetic code amino acids from 1st binds to 2nd amino acid equalling a peptide bond.

1st tRNA floats into cytoplasm to find another specific amino acid.

Process repeats- long polypeptide chain until stop codon, translator stops, polypeptide chain is released

Question 4

Discuss relationship 1 gene and one polypeptide.

Answer 4

Gene : sequence of DNA codes a polypeptide sequence.

A gene sequence is converted into a polypeptide sequence through transcription and translation.

Exception:
Genes encoding for tRNA and rRNA do not code for polypeptide sequences (only mRNA sequences code for polypeptides)
A single gene may code for multiple polypeptides if alternative splicing occurs (the removal of exons as well as introns)