1.DNA Denaturation(变性) When duplex DNA molecules are subjected to conditions of pH ,temperature,
or ionic strength that disrupt base-paring interactions, the DNA molecule has lost its’native conformation, and double helix DNA is separated to single strand DNA as individual randome coils.
浙江师范大学寝室中毒That is, the DNA is denatured.
2.Renaturation（复性）Removing the denaturation factors slowly or in proper conditions, the denatured
DNA (ssDNA) restore native structure (dsDNA) and functions. This process is dependent on both DNA concentration and time.
3.Hybridization （核酸分子杂交）when heterogeneous DNA or RNA are put together, they will become to
heteroduplex via the base-pairing rules during renaturation if they are complementary in parts (not completely). This is called molecular hybridization.
4.Hyperchromic effect （增效应）The absorbance at 260 nm of a DNA solution increases when the
double helix is separated into single strands because of the bases unstack.
5.Ribozyme （核酶）are the RNA molecules with catalytic activity. The activity of these ribozymes often
involves the cleavage of a nucleic acid.
6.De novo synthesis (从头合成)De novo synthesis of nucleotides begins with their metabolic precursors:
amino acids, ribose-5-phosphate, one carbon units, CO2. mostly in liver.
7.Salvage pathways （补救合成）Salvage pathways recycle the free bases and nucleosides released from吾守尔大爷的冰
nucleic acid breakdown. Mostly in brain and marrow.
8.Semi-conservative replication (半保留复制）DNA is synthesized by separation of the strands of a
parental duplex, each then acting as a template for synthesis of a complementary strand based on th
e base-paring rule. Each daughter molecule has one parental strand and one newly synthesized strand. 9.Telomere（端粒）：Specialized structure at the end of a linear eukaryotic chromosome, which consists of
proteins and DNA, tandem repeats of a short G-rich sequence on the 3 ' ending strand and its complementary sequence on the 5' ending strand, allows replication of the extreme 5' ends of the DNA
without loss of genetic information and maintains the stability of eukaryote chromosome.
10.Telomerase（端粒酶）An RNA-containing reverse transcriptase that using the RNA as a template, adds
nucleotides to the 3 ' ending strand and thus prevents progressive shortening of eukaryotic linear DNA molecules during replication.
11.Reverse transcription (逆转录）Synthesis of a double-strand DNA from an RNA template.
12.Reverse transcriptase (逆转录酶）A DNA polymerase that uses RNA as its template.
activity: RNA-dependent DNA polymerase; RNAse H;DNA-dependent DNA polymerase
13.The central dogma (中心法则）It described that the flow of genetic information is from DNA to RNA and
then to protein. According to the central dogma, DNA directs the synthesis of RNA, and RNA then directs the synthesis of proteins.
14.asymmetric transcription（不对称转录）1..Transcription generally involves only short segments of a
DNA molecule, and within those segments only one of the two DNA strands serves as a template.
2.The template strand of different genes is not always on the same strand of DNA. That is, in any
chromosome, different genes may use different strands as template.
between template and transcript is base paring and anti-parallel)
<-template strand (or coding strand)（编码连）The DNA strand that opposites to the template
strand.(Note that it has the same sequence as the synthesized RNA, except for the replacement of U with T )
煤矿施工组织设计17.promoter i s the DNA sequence at which RNA polymerase binds to initiate transcription. It is always
located on the upstream of a gene.
18.Split genes (断裂基因)Split genes are those in which regions that are represented in mature mRNAs or
structural RNAs (exons) are separated by regions that are transcribed along with exons in the primary RNA products of genes, but are removed from within the primary RNA molecule during RNA processing
steps (introns).
19.Exon(外显子) can be expressed in primary transcript and are the sequences that are represented in
mature RNA molecules, it encompasses not only protein-coding genes but also the genes for various RNA (such as tRNAs or rRNAs)江西食品网
20.Intron（内含子）can be expressed and be the intervening nucleotide sequences that are removed from
the primary transcript when it is processed into a mature RNA.
21.Spliceosome（剪切体）A multicomponent complex contains proteins and snRNAs that are involved in
mRNA splicing.
22.Translation（翻译）The process of protein synthesis in which the genetic information present in an
mRNA molecule (transcribed from DNA) determines the sequence of amino acids by the genetic codons.
Translation occurs on ribosomes.
in each mRNA, also called triplet. Genetic code defines the relationship between the base sequence of mRNA and the amino acid sequence of polypeptide.
24.Degeneracy of code（密码子简并性）One codon encodes only one amino acid;
More than 2 codons can encode the same amino acid;
Most codons that encode the same amino acid have the difference in the third base of the codon.
25.ORF（开放阅读框架）The nucleotideacids sequences in mRNA molecule from 5’AUG to 3’stop codon
(UAA UAG UGA). It consists of a group of contiguous nonoverlapping genetic codons encoding a whole protein. Usually, it includes more than 500 genetic codons.
26.Shine-Dalgarno sequence（SD）is a sequence upstream the start codon in prokaryotic mRNA that can
base pairs to a •UCCU•sequence at or very near the 3' end of 16S rRNA, thereby binding the mRNA and small ribosomal subunit by each other.
情报杂志27.Polyribosome（多聚核糖体）Ribosomes(10~100) are tandemly arranged on one mRNA and move in the direction of 5’to 3’.Such a complex of one mRNA and a number ofribosomes is called polyribosome.
28.signal peptide（信号肽）It is a short conservative amino terminal sequence (13~36AA) that exists on
a newly synthesized secretory protein. It can direct this protein to a specific location
within the cell. It is subsequently cleaved away by signal peptidase; also called signal sequence and targeting sequence.
29.Operon（操纵子）: Bacteria have a simple general mechanism for coordinating the regulation of genes
whose products are involved in related processes: the genes are clustered on the chromosome and t
ranscribed together. Most prokaryotic mRNAs are polycistronic. The single promoter requi red to initiate transcription of the cluster is the point where expression of all of the genes is regulated. The gene cluster, the promoter, and additional sequences that function in regulation are together called an operon. Operons that include 2 to 6 genes transcribed as a unit are common; some operons contain 20 or more genes.
30.Housekeeping gene（管家基因）Genes that are expressed at a fairly consistent level throughout the cell
cycle and from tissue to tissue. Usually involved in routine cellular metabolism. Often used for comparison when studying expression of other genes of interest.
31.Trans-acting factors（反式作用因子）：Usually considered to be proteins, that bind to the cis-acting sequences to control gene expression. The properties of different trans-acting factors:
subunits of RNA polymerase
bind to RNA Polymerase to stabilize the initiation complex
bind to all promoters at specific sequences but not to RNA Polymerase (TFIID factor which binds to the TATA box)
bind to a few promoters and are required for transcription initiation
数学竞赛之窗32.Cis-acting elements（顺式作用元件）：DNA sequences in the vicinity of the structural portion of a gene
that are required for gene expression. The properties of different cis-acting elements:
contain short consensus sequences
modules are related but not identical
not fixed in location but usually within 200 bp upstream of the transcription start site
a single element is usually sufficient to confer a regulatory response
can be located in a promoter or an enhancer
assumed that a specific protein binds to the element and the presence of that protein is development
ally regulated
33.Southern blotting：Genomic DNA (from tissues or cells) are cut by RE, separated by gel
electrophoresis and denatured in solution, then transferred to a nitrocellulose membrane for detecting specific DNA sequence by hybridization to a labeled probe. It can be used to quantitative and qualitative analyze genomic DNA, or analyze the recombinant plasmid and bacteriophage (screening DNA library).
34.Northern blotting: RNA samples (from tissues or cells) are separated by gel electrophoresis and
denatured in solution, then transferred to a nitrocellulose membrane for detecting specific sequence by hybridization to a labeled probe. It can be used to detect the level of specific mRNA in some tissues (cells) and to compare the level of same gene expression in different tissues (cells) or at different development period.
35.Western blotting：rotein samples are separated by PAGE electrophoresis, then electro-transferred to NC
membrane. The proteins on NC membrane hybridize with a specific antibody (1st antibody ), then th
e target protein binding with antibody is detected with a labeled secondary antibody (2nd antibody).
Also called immunoblotting. It can be used to detect the specific protein, semi-quantify specific protein, etc.
36.PBlotting technique（印迹）:Transfer (blot) biological macromolecules separated in the gel and fix them
to nitrocellulose/nylon membrane by diffusion, electro-transferring or vacuum absorption, then detect
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