Chromatin, Operons, & DNA Replication Flashcards
progeria: interruption with
nuclear lamina
we know about proteins due to the … that occur with them
proteins
heterochromatin is a … version of chromatin
densely packed
heterochromatin leads to … of genes by inhibiting … at these locations, prevents access of … necessary for transcription
inactivation; transcription; enzymes
euchromatin are … chromatin –> … occurs in these regions
loosely packed; transcription
chromatin consists of … and .., namely DNA wrapped around … to form … that are held together either as “… on a …” (…) or as a structure of … in width (…)
DNA; proteins; histones; nucleosomes; beads; string; euchromatin; 30 nm; heterochromatin
about .. base pairs of DNA wrap around complexes of … histones, composed of … of each of the four different types: …, …., …, …
150; 8; two; H2A; H2B; H3; H4
Nucleosomes are joined together by way of
linker DNA
chromosomes are formed during …, when the cell is undergoing …
mitosis; cellular division
in …, chromatin begin to condense, which is when the chromosome becomes visible. During …, in which the cell is not dividing, the chromatin is in its … state, allowing for … to occur
prophase; interphase; least condensed; transcription
modification of the … regulates gene expression
histone tail
…. of the histone (addition of an … group) … the coils
…. (addition of a … group) … the coils
acetylation; acetyl; loosens; methylation; methyl; tightens
…. reduces the space needed for DNA within the cell. It reduces the … on the molecule by allowing it to … around itself. It can also regulate …
supercoiling; helical stress; twist; transcription
positive supercoiling: DNA is … –> …-handed twisting of the DNA
negative supercoiling: DNA is … (most DNA like this) –> …-handed twisting of the DNA, makes it easier to … the DNA strands
overwound; left; underwound; right; separate
epigenome refers to the … that regulate gene expression (e.g. …, …, etc.)
can be influenced by … factors
chemical compounds/modifications; DNA methylation; histone methylation; environmental
operon –> grouping of
genes
prokaryotes have to control which genes will be expressed, based on the … that they are in
environment
E.coli cells in environment with glucose, maltose and lactose would select … first in their metabolic genes, breaking it down by way of … (which involves … enzymes, leading to a net yield of … ATP). They would then select either maltose or lactose, building the enzymes responsible for breaking them down.
glucose; glycolysis; 9; 2
repressor proteins sit on top of …. and block …
gene segment; transcription
glucose is the …, … energy source
preferred; universal
operons are named after their … (what they act on)
substrate