BIOL 411 Study Guide - Quiz Guide: Histone Octamer, Central Dogma Of Molecular Biology, Coding Strand
Bio 411.01
Additional Tegrity Lecture- end of chapter 3
• Choati: the stuff of DNA i eukaoti hoosoes
o Unit of chromatin= nucleosome (150 bp of DNA wrapped around histone
octamer 1¾ times)
▪ Nucleosomes connected by linker DNA
o Histone octamer: composed of two each of four histones (H2A, H2B, H3, H4), 8
total histone proteins
▪ Histones: small, basic (many lysine, arginine), highly conserved, meaning
they are found in all eukaryotes (few changes in amino acid sequence of
histones in all eukaryotes- shows that they are very important and cant
be changed)
• Epigenetics: much of it involves reversible covalent modifications of the lysines (K) and
arginines (R) in the N-terminal tails of the histones in the nucleosomes
o Adding acetyl, methyl, etc. groups to lysines and arginines regulates DNA
expression/replications/ etc.
• The central dogma: the flow of genetic information
o The nature of genetic information:
▪ Coding information: codons code for amino acids in proteins
▪ Other forms of information: origins of replication, promoters,
centromeres, etc.
o Central dogma of molecular biology: DNA→RNA→Protein
▪ Info of DNA is transcribed into mRNA, which is translated into encoded
protein
• Regulated heavily at every step
▪ Different in prokaryotic cells:
• In prokaryotes, the entire central dogma takes place in the cell (no
nucleus)
• In Eukaryotes, separation of time and place; transcription takes
place in nucleus, translation takes place in the cytoplasm
• DNA vs. RNA
o 1. Ribose Sugar:
▪ RNA: ribonucleic acid- Riose ’ C has a OH)
▪ DNA: deoxyribonucleic acid- Deoiose ’ C has a H
o 2. T and U
▪ RNA: G,C,A,U
▪ DNA: C,G,A,T
o Strands
▪ RNA: single stranded
▪ DNA: double stranded
• Kinds of RNA:
o mRNA- codes for proteins
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