Gene and Chromosome

Parental DNA is copied to daughter DNA

Replication

DNA is used as template to synthesize RNA

Transcription

RNA is used as template to synthesize protein

Translation

a chromosomal segment that encodes for single polypeptide chain, RNA molecule, or plays regulatory function

Gene

total genetic information contained in cell, organism, or virus

Genome

compact strand of DNA that is encoded with genes; composed of chromatin; and is formed during nuclear division

Chromosome

DNA complex with histones & other proteins ; is typically dispersed throughout nucleus during interphase

Chromatin

DNA → mRNA; one strand of the double stranded DNA acts as molecular template for RNA Synthesis

Transcription

When three Nucleotides code for specific amino acid or signal

Codon

mRNA ->tRNA; when codon (triplet of nucleotides) in mRNA binds to complementary triplets in tRNA where RNA carry the complementary amino acid used to create proteins

Translation

protein assemblies in which DNA is wrapped around and it helps eukaryotic DNA to be compacted and confined to within the nucleus

histones

a compact structure that is made up of bacterial DNA that is highly compacted & supercoiled

• it exists in the cytosol with few attachments to the membrane

Nucleoid

Experiment that suggests that living organism could get by with less than 400 genes

Craig Venter’s

• viral genomic DNA is associated with _____ proteins

• prokaryotic DNA is associated with ____ proteins

• eukaryotic DNA is associated with ____ proteins

capsid, nucleoid, chromatin

expressed sequences that are translated into amino acid sequence

exons

regions of genes that are transcribed but not translated

introns

created when introns are removed exon mRNA sequence are sticked together

mature transcript

Sequences that can move around within genome of single cell

• accounts for 5% of human genome

transposons

Simple Sequence Repeats (SSRs) is also known as _____

• they are made of 10 bp or less and are repeated millions of time

Satellite DNA

SSRs are associated with _____

telomeres and centromeres

region where two daughter chromosome are held tgt during mitosis (after DNA replication but before cell division)

• is essential for equal distribution of chromosome sets to daughter cells

• have AT rich repeated sequences of about 130 bp

centromere sequences

caps the end of eukaryotic chromosomes

telomere sequences

enzyme that adds special loop structures to keep DNA endsfrom unraveling

telomerase

Hayflick limit: normal human cells can only divide ~____ times before losing ability to divide again because after each round of replication , telomeres are shortened thus, cellular DNA "ages"

52

• _____: relaxed DNA ; 10.5 bp/turn

• ____: DNA in closed loops; rarely relaxed → strain due to fewer helical turns (underwinding) induces supercoiling

  • underwinding makes later separation of strand easier

• _____ : underwound with help of protein to prevent strands from rotating

Normal B form, closed circular, linear

describes supercoiling->an integer for closed circular DNA and is (+), reflecting a right hand helix

Linking Number

DNA that differ only in linking number

• same # of bp, same sequence, different degree of supercoiling

• conversion between topoisomers require DNA strand break

topoisomers

enzymes required for DNA unwinding & rewinding during transcription & replication

topoisomerases

Topoisomerases makes cut in 1 strand ; changes Lk by 1

• includes Topo I and III

• removes negative supercoil and increases Lk

Type I

Topoisomerases makes cut in 2 strand ; changes Lk by 2

• includes Topo II and IV

• introduces negative supercoil and decrease Lk

Type II

drug that Inhibits bacterial Type II topoisomerases from binding ATP

Coumarins (novobiocin, coumermycin)

drug that inhibits last step of resealing DNA strand breaks → is wide spectrum selective for bacterial enzyme

quinolones (nalidixic acid, ciprofloxacin, Cipro)

Drugs that are Eukaryotic Type I Isomerase inhibitors (traps enzyme DNA complex in its cleared state)

camptothecin, irinotecan (Campto) topotecan (Hycamtin)

fiber of protein, DNA, and small amount of RNA

chromatin

Histones are made of basic residues

Lysine, Histamine, Arginine (KHR)

discrete units with DNA and protein

nucleosomes

region where sequence specific, non-histone protein binds

• Nucleosome formation compacts DNA 7- >10K fold → are where Next level of structure for nucleosome

territories

proteins that ensure shape of higher level structures are maintained (along with Topo II)

SMC (Structural Maintenance of Chromosomes)

Type of SMC Proteins

• helps link sister chromatids

cohesin

Type of SMC Protein

• help chromosomes to condense; create positive supercoils

condensin