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Detergents

def: most widely used disruptive agents.

info: they are small and amphipathic. These only ever have one hydrophobic tail. They act differently from phospholipids. Detergent molecules are shaped like cones. Unlike lipids, they don't form bilayers but form clusters in water called micelles.


Deoxyribonucleic acid (DNA)

description: made of two long polynucleic chains. Each chain is made up of four nucleic sub units, and the two chains are held together by hydrogen bonds between the base portion of the nucleotides.


DNA Repair (chapter 6)

def: Collective term for the enzymatic process that correct deleterious changes affecting the continuity or sequence of a DNA molecule.


DNA Replication (chapter 6)

def: The process by which a copy of a DNA molecule is made.


DNA hybridization

def: the process by which different chromosomes are dyed differnt colors with flouresent dyes.


DNA polymerase (chapter 6)

what do: it synthesizes new DNA using one of the old strands as a template

it does not dissociate form the DNA each time it adds a new nucleotide to the chain, but instead it stays associated with the DNA and moves along the template strand

it can add new subunits only to the 3' strand. therefor, new DNA can only be synthesized in a 5' to 3' direction.

it is very accurate, making about one error in every 10^7 nucleotide pairs it copies.


Double helix (chapter 5)

def: Typical conformation of a DNA molecule in which two polynucleotide strands are wound around each other with base pairing between strands.


Diacylglycerol (DAG) (chapter 16)

def: Lipid produced by the cleavage of a membrane inositol phospholipids in response to extracellular signals. Composed of two fatty acids linked to a glycerol, it serves as a membrane-located signaling molecule to help activate protein kinase C.


Dynamic Instability (chapter 17)

def: The property shown by microtubules of growing and shrinking repeatedly through the addition and loss of tubuilin subunits from their exposed ends.


Dyein (chapter 17)

def: Member of a family of large motor proteins that undergo ATP-dependent movement along microtubules. Dyein is responsible for the bending of cilia.


DNA Mismatch repair (chapter 6)

dedicated to correcting the rare mistakes made in DNA replication..Replication makes approximately one error in 10^7 paried nucleotides copied, and DNA mismatch repair fixes 99% of these errors..lowering the error rate to 10^9 errors made in paired nucleotides copied.

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Differentiation (chapter 8)

def: Process by which a cell undergoes a progressive change to be a more specialized and usually recognized cell type.


DNA Methylation (chapter 8)

def: The enzyme addition of methyl groups to cytosine bases in DNA. Methylation generally turns off genes by attracting proteins that block gene expression.

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Dideoxy DNA Sequencing (chapter 10)

def: The standard method of DNA sequencing. It utilizes DNA polymerases and chain-terminating nucleotides.


DNA Cloning (chapter 10)

def: Making many identical copies of a cell or DNA molecule or an organism.


DNA Library (chapter 10)

def: Collection of cloned DNA molecules, representing either an entire genome (genomic library) or copies of the mRNA produced by a cell (cDNA library)


DNA Ligase (chapter 10)

def: Enzyme that joins two DNA strands together end to end.


DNA Microarray (chapter 10)

def: A glass slide upon which a large number of short DNA molecules (typically in the tens of thousands) have been immobilized in an orderly pattern. Each of these DNA fragments acts as a probe for a specific gene, allowing the RNA products of thousands of genes to be monitored at the same time.


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