Proteins
This part of the amino acid determines the bio-chemical properties of amino acids
What is the R group?
This protein requires ATP and the predominant type moves 5’ to 3’ along only the DNA lagging strand template
What is DNA helicase?
Name 1 difference and 1 similarity between the RNA polymerase and the DNA polymerase in bacteria
RNA polymerase doesn’t need a primer to begin but it is not as accurate/RNA uses ribonucleoside triphosphates and DNA uses deoxyribonucleoside triphosphates. They both add nucleotides from the 5’ to 3’ direction
*DOUBLE* What are 2 differences in mRNA structure between prokaryotes and eukaryotes? What is a similarity?
Prokaryotes have Shine-Dalgarno Sequences (ribosome binding sites), eukaryotes have a 5’ cap and a 3’ tail. Both prokaryotes and eukaryotes have 5’ and 3’ UTR
Name 3 differences between prokaryotic and eukaryotic cells
Eukaryotic cells have a nucleus, membraned bound organelles, are larger in size and have more DNA
These bonds are strong covalent bonds that happen between 2 cysteine in the same or different polypeptide chains
What are disulfide bonds?
*DOUBLE* This protein relieves the supercoiling and torsional strain that occurs when helicase unwinds the DNA
What is topoisomerase?
This shape is formed on the bacteria RNA strand when transcription is terminated and why does this shape form?
Hairpin structure is formed as a result of the triple hydrogen bonded G-C rich sequences
What are the two strategies to manage codon redundancy for translation?
More than 1 tRNA for many amino acids/ some tRNA can recognize and base pair with more than 1 codon
What are the three parts of a nucleotide?
Pentose sugar, nitrogenous base and phosphate group
To form a peptide bond, there is a reaction between those two groups of the amino acid
What is the carboxyl group and the amino group
What are the 2 characteristics of the sequences at replication origins?
They are A-T rich and are able to be recognized by and bound by the initiator protein
What is the group of proteins that help position eukaryotic RNA polymerases at promoters, and what “helper” of the bacterial RNA polymerases perform a similar function?
Transcription factors help eukaryotic RNA polymerase, and they are similar to sigma subunits
Name 1 example of a covalent post-transitional modification and name 2 reasons why covalent modification may be required
Phosphorylation/glycosylation. They might be required to make protein active or recruit protein to correct membrane or organelle
*DOUBLE* What charge do histones carry and why is this significant?
Histones carry positive charges to allow tight binding with the negatively charged DNA
*DOUBLE* Eukaryotic proteins often have domains that are connected by sequences of this characteristic
What are intrinsically disordered sequences/ What are flexible sequences?
Which DNA template strand is bent in prokaryotes and why does this occur?
The lagging strand template is bent and it is so that the DNA polymerases can bind to each other and work in the same direction as they are more efficient when working together
What is the reaction that activates RNA polymerase II? What amino acid is undergoing this reaction and where is this amino acid located on RNA polymerase II?
Phosphorylation occurs. The SER amino acid on the Carboxyl terminal domain of the largest subunit of the RNA polymerase II is phosphorylated.
What are the 2 roles of the elongation factors and what are they mediated by in both eukaryotes and prokaryotes?
The elongation factors improve speed and efficiency of translation and have the error checking function. They are mediated by GTP hydrolysis and release of EF1 and EF2 in eukaryotes and EF-Tu and EF-G in prokaryotes.
What are the two regions of interphase chromosome and how does gene expression differ between the regions?
Euchromatic regions = expressed gene expression, heterochromatic regions = suppressed gene expression
How do the hydrogen bonds differ in Alpha helices and Beta sheets
In Alpha helices, the bonds are 4 amino acids apart and the bonds form between the same segment of the polypeptide chain. In Beta sheets, the bonds are between amino acids in different segments (strands) of the polypeptide chain
What kind of body cells have high levels of telomerase, and what kind has low levels?
Germ-line cells have high levels of telomerase, somatic cells have low levels.
*DOUBLE* During the 3’ end processing of the mRNA, the RNA is cleaved via the breaking of the ____ bond and the addition of a ______ along with ______ proteins. This result in a mature mRNA.
Phosphodieter bond, poly-A 3’ tail, Poly A-binding proteins
What are 3 things the rRNAs in the ribosome is responsible for and what is 1 thing the proteins in the ribosome is responsible for? Because of these responsibilities, the ribosome is said to be an example of a ______
The rRNA is responsible for 1. the structure of the ribosome, 2. its ability to get parts needed for protein synthesis into position and 3. making peptide bonds between amino acids. The protein is involved in folding and stabilizing the RNA core in the ribosomal subunits. The ribosome is a ribozyme.
What are the two steps required for the removal of introns from pre-mRNA? And what is the resulting structure that forms?
Branch point A attacks the 5’ splice sit of the intro sequence then the 3’ of one exon reacts with the 5’ of the next exon to release the introns in the formation of the lariat structure