bacterial chromosomes

• one, single chromosome
• chromosome is circular
• sinigle origin of replication
• ~5 Mb long

components involved in bacterial replication

• DnaA - initiates replication
• Helicase - unwinds the double helix
• Primase - makes primers
• DNA polymerase - assists with binding fragments and strands 
• DNA ligase - seals the nicks in the DNA backbone
• single stranded binding protein - binds to the entire single stranded sequence to protect it while it's exposed

RNA polymerase

• core RNA with 4 subunits
• has a sigma factor

bacterial translation

• 70S ribosome
• RBS 
• starts with formyt-Met

bacterial gene arrangement

• several genes, several protein coding sequences
• one promoter, one terminator (collectively called an operon)
• polycistronic mRNA - the mRNA molecule that reflects multiple genes
• proteins that are encoded on an operon are similarly related to one another (similar in function)

archaeal chromosome strutuctre

• one, single chromosome
• chromosome is circular
• few origins of replication
• ~5-10 Mb long

component that assists in archaeal replication

• DnaA

Archaeal RNA polymerase

• many unit RNA polymerase (very complex)
• lacks a sigma factor
• have a TATA-binding protein (TBP)
• has TFB (transcription factor B)
• TBP + TFB act as a sigma factor, signaling the promoter

archaeal translation

• 70S ribosome
• RBS
• starts with Met

archaeal gene arrangement

• several genes, several protein coding sequences
• one promoter, one terminator (collectively called an operon)
• polycistronic mRNA - the mRNA molecule that reflects multiple genes

eukaryotic chromosome structure

• multiple chromosome
• chromosomes are linear 
• many origins of replication 
• ~5-10 Mb in each chromosome

eukaryotic replication involves..

• telomerase
• which deals with the problem of replication linear chromosomes
• adds telomere repeats to the end of the chromosome

eukaryotic RNA polymerase

• three very complex RNA polymerases, each made up of many subunits
• lack a sigma factor
• have a TATA-binding protein (TBP)
• has TFB
• TBP + TFB act as a sigma factor, signaling the promoter

eukaryotic translation

• 80S ribosome
• NO RBS
• starts with Met

eukaryotic gene arrangement

• one promoter, one terminator
• this mRNA only reflects one protein

semiconservative DNA replication

• the parent strands separate
• one cell gets strand A, the other cell gets strand B
• complementary strands are synthesized

histones

• wrap the DNA around clusters of histones to form a nucleosome
• not present in bacteria

replication fork

• helicase moves along the DNA strand, unwinding it, while DNA polymerase follows along
• DNA polymerase makes the lagging strand
• where the strands are being separated and then being synthesized is the actual replication fork

codons

• made up of 3 bases
• genetic code is a triplet code
• standard start codon - AUG
• standard stop codon - UAA, UGA, UAG
• complement to the codon is the anticodon

protein export in bacteria

• proteins are made during translation and destined for certain places
• the N-terminus contains the signal sequence (which gets recognized by the secretion apparatus)
• takes the protein to the membrane, makes a core through the membrane to excrete the protein
• some proteins cannot fold on their own outside of the cell 

TAT system

• takes a fully folded protein and takes it out of the cell without having to unfold it 
• this is important for proteins with prosthetic roots
• chaperones help the proteins fold if they cannot on their own