(Ch 10-11) Transcription/Translation Flashcards
What does a Christmas tree structure represent?
an active transcription of a gene
What is the primary structure of a protein?
The linear sequence of amino acids (stabilized by peptide bonds between adjacent amino acids)
What is the secondary structure of protein?
The alpha helix and beta-pleated sheet (stabilized by hydrogen bonds between backbone atoms of non-adjacent amino acids; no R groups are involved in bonding at the level)
What is the tertiary structure of a protein?
The 3D shape (bonding is between R groups of nonadjacent amino acids; involves disulfide bridges between cysteine residues, ionic or salt bridges, hydrogen bonds, hydrophobic interactions)
What is the quaternary structure of a protein?
Involves more than one polypeptide chain serving as subunits in a larger complex (all bond types may be involved:. Not all proteins have a quaternary structure.
Name two types of tertiary structures.
Globular or fibrous
How do sugars of RNA and DNA differ?
Sugar of RNA has a 2’ hydroxyl group that is not found in the sugar of DNA.
What type of mutation results in no change to the amino acid sequence?
Silent mutation
What is a poly-A tail?
A string of 50-150 adenine-containing nucleotides added to the trimmed 3’ end of the mRNA
What events cause a gene to suffer from “position effects”?
A gene that has been moved from one chromosomal region to another via inversion or translocation, or genes that are introduced by a virus, or genes close to where a virus is inserted
Name the two types of nucleotides and the three components of a nucleotide
a. Ribose and Deoxyribose
b. 1 pentose sugar, 1 phosphate group, 1 nitrogenous base
Name and describe the three alternative forms of DNA.
B-form - “biologically relevant, “ Watson and Crick
A-form - right-handed helix, compact, exists under dehydration
Z-form - left-handed helix, from synthetic DNA with C-G pairs
What are introns?
Non coding sequences that interrupt the coding sequences (exons) of genes. They are common in eukaryotic cells but rare in bacterial cells.
True or False: Transfer RNA (tRNA) is attached to an amino acid.
True
Where are ribosomal RNA (rRNA) located in eukaryotes?
Cytoplasm
True or False: the DNA transcription start point for the mRNA is different from the translation start point for the tRNA
True
tRNA start point AUG