Transcription, Translation, and Mutation

How is RNA's structure different from DNA?

SINGLE helix; >>U<

What base replaces thymine?

Uracil

Name the 3 components of a RNA nucleotide

phosphate group, sugar (ribose), nitrogenous base (U, A, C, G)

What does the mRNA do?

Messenger RNA; carries copies of DNA's instructions

What does the tRNA do?

Transfer RNA; transfers amino acids in the cytoplasm to the ribosomes for protein synthesis

What does the rRNA do?

Ribosomal RNA; found in the ribosomes where proteins are assembled

Define transcription

The process of creating mRNA from DNA, which will then act as a "script" for creating proteins

Where does transcription occur?

Nucleus

Which enzyme is responsible for creating mRNA molecules by using DNA as a template?

RNA polymerase

What is step 1 of transcription?

RNA polymerase binds and separates the strands of DNA for a specific gene which codes for a specific protein

What is step 2 of transcription?

One strand of DNA is used as a template for the new mRNA strand

What is step 3 of transcription?

Termination point on the gene signals RNA polymerase to stop

What are cut out of mRNA sequence, and what are kept in?

Introns are cut out, exons are bonded together to form a complete mRNA strand

What is the purpose of introns?

They make us unique

What are the monomers for proteins?

Amino Acids

What is a codon?

3 bases on the mRNA strand

What is an anticodon?

set of 3 bases found on the tRNA molecule that matches a codon

What is translation?

The creation of a protein

What is step 1 of translation?

Ribosome attaches to mRNA strand; tRNA sees start codon (AUG) on mRNA molecule and begins translation; each codon is translated to bring a matching tRNA with the right amino acid

What is step 2 of translation?

polypeptide chain (protein) continues to grow by bonding amino acids through peptide bonds

What is step 3 of translation?

Translation ends when tRNA sees a stop codon on the mRNA molecule; polypeptide chain is released

What is the Central Dogma of Biology?

DNA--(transcription)-->mRNA--(translation)-->amino acids--(polypeptide bonding)-->proteins

What is a mutation?

a change in the genetic material

What is gene mutation?

Mutation that produces changes in a single gene, also called point mutation, because it involves changes in 1 or a few nucletodies

What are some examples of gene mutations?

Substitution, Insertion/Deletion, Frameshift Mutation

What is the difference between substitution and base pair substitution?

Substitution replaces 1 nucleotide in a DNA sequence with another; base pair substitution replaces 1 nucleotide and its compliment with another

What is chromosomal mutation?

Mutation that involves changes in the number or structure of chromosomes

What are some examples of chromosomal mutations?

Deletion, Duplication, Inversion, Translocation

What is a missense?

result of substitution--still codes for an amino acid but is not the one needed

What is a nonsense?

result of substitution--changes an amino acid codon to a stop codon, resulting to pre-mature termination

What is insertion/deletion?

Nitrogen bases (A, T, G, C) inserted or deleted from the sequence; can be more dramatic than substitution

What is loss of all or part of a chromosome?

Deletion