Term
Degenerate- more than one triplet per aa Redundant- two first bases are same for specific aa Unambiguus- no codon encodes more than one aa non-overlapping- codons are read sequentially not puctuated- no interuptions universal (almost) |
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Definition
| Properties of the genetic code |
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Term
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Definition
Start codon= ? Stop codons= ? |
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Term
L aminoacyl accepter D T tertiary |
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Definition
Key interaction sites of tRNA: One end of '_' is the anti-codon containing loop for mRNA recognition, the other end of it is the _________ ________ stem with a conserved sequence to charge the tRNA, and finally the _ and _ loop residues are highly conserved for ____ interactions. |
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Term
| aminoacyl tRNA synthetase |
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Definition
| tRNAs are 'charged' by _________ ____ __________, using ATP-activated amino acid. |
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Term
Prokaryotic: 70S (30S and 50S) Eukaryotic: 80S (40S and 60S) |
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Definition
| Difference between prokaryotic and eukaryotic ribosomes? |
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Term
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Definition
| RNAP I synthesizes ____ in the _________, while RNAP III synthesizes ____ and other small RNAs in the _______. |
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Term
TRUE also...RNAP I catalyzes simultaneous synthesis of polycistronic rRNA (45S precursor) |
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Definition
True of False? Multiple rRNA transcripts can be made simultaneously from multiple rRNA genes. |
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Term
1- 40S subunit binds tRNA (PIC formation (43S)) 2- mRNA activation 3- mRNA binds small subunit (48S) 4- Activated 80S ribosome forms |
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Definition
| The four major steps of the initiation of translation? |
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Term
Initiation factors (elF 1,2,3) GTP methionyl-tRNA^met the whole complex is energized by GTP hydrolysis |
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Definition
| WHen the 40S ribosomal subunit binds tRNA, the 40S subunit must bind 3 things: |
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Term
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Definition
| During mRNA activation of the initiation of translation, the mRNA is activated by _____ complex and the complex binds at the ___ via ___ __________. |
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Term
43S pre-initiation complex (PIC) hydrolyzed elF-4 |
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Definition
When mRNA binds the small ribosomal subunit, the elF-4/mRNA complex joins the ___ ___-__________ complex. Once mRNA translocates the the start codon, ATP is __________ and _____ dissociates. |
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Term
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Definition
| Activated 48S initiation complex joins 60S subunit with the assistance of _____. During this process ___ is hydrolyzed. |
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Term
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Definition
| _______ and growth factors stimulat mRNA activation and translocation. |
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Term
1- Binding of aminoacyl-tRNA to the 'A' site 2- Peptide bond formation 3- translocation |
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Definition
The three steps of Elongation? |
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Term
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Definition
| The first step of elongation involves the aa-tRNA binding to the ________ complex. Once bound, the entire complex will bind the _ site on an activated 80S ribosome. ___ is hydrolyzed at this step and ________ is released. |
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Term
peptidyl transferase 28S Ribozyme |
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Definition
| The peptide bond formed in step two of elonogation is formed by ________ ___________ of ___ rRNA of the 60S subunit. rRNA is acting like an enzyme, therefore it is called a ________. |
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Term
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Definition
| During translocation, the _______ complex binds to and displaces peptidyl tRNA from A site to P site. The deacylated tRNA dissociates. ___ is hydrolyzed and mRNA translocated forward on codon, leaving a site ope. |
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Term
A UAG, UAA, UGA RF-GTP peptide tRNA GTP |
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Definition
| Termination occurs when the _ site reaches a stop codon (___, ___, or ___). Release factor, ______ complex binds, causing the _______ and ____ are released, driven by ___ hydrolysis. |
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Term
4 Breakdown: 1ATP in tRNA chargins 1GTP in aa-tRNA delivery 1GTP during translocation total: 4 ATP equivalent per aa |
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Definition
| Translation requires _ ATP per amino acid |
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Term
IRES (internal ribosome entry site) ElF-4F IRES elF-4G |
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Definition
| Viruses co-opt host protein synthesis via ____. This causes the ______ complex to abort, the mRNA cap is not recognized, and viral ____ is recognized instead by ______ causing viral mRNA to be preferentially translated. |
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Term
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Definition
| _________ occur when multiple proteins are made simulatneouslly from a single mRNA. |
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Term
1-Folding 2-Signal sequence targeting (to mbs or other locations) 3-selective proteolysis (cleavage leads to active enzyme) 4- Assembly for multi-subunit complexes) 5-Post-translational modification 6-Turnover |
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Definition
| Proteins are processed in 6 ways after synthesis: |
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Term
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Definition
| Globular proteins are often water-soluble, with primarily ___________ exterior and ___________ interior. |
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Term
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Definition
| Non-covalently associated subunits in within a protein are called _______ and are very important in a proteins __ structure. |
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Term
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Definition
| Aplha helix has ___ aa per one turn. ______ hold the structure together on the inside, while the ________ point away from the helix. |
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Term
Perpindicular stacking *Natural silk interdigitates oily methyl groups to produce that 'silky' feel* |
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Definition
In a beta-pleated sheet R-groups are _____________ to the sheet and alternate up and down along each chain (this allows for ________). |
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Term
single 4 alpha helices prosthetic |
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Definition
Ribonuclease is a small single chain protein, while Hemoglobin (Hb) is a ______ chain protein with _ nearly identical subunits. The secondary structure is composed mostly of _______ _______ and each subunit contains one Heme group which is a __________ group. |
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Term
4 disulfide 3 folding motifs motif beta-sheets beta-barrel |
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Definition
| Immunoglobulin G has _ chains with internal _________ bonds and _ domains. Domains can be characterized in terms of one or more _______ ______. Note that IgG domains are built on a repeated _____ of __________ folded into a ____ ______. |
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Term
1- predominately alpha helix 2-predominantly beta-sheet 3- mixed |
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Definition
| There are three general protein folding motifs: |
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Term
zinc finger leucine zipper helix turn helix (HTH) helix loop helix (HLH) |
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Definition
| Four common sturcture motifs in DNA binding proteins: |
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Term
1- Spontaneous (usually small, cytoplasm proteins) 2- Rapid Chaperone-assisted folding 3 Membrane proteins are targeted and assisted in membrane insertion by a signal peptide sequence and signal recognition protein (SRP) |
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Definition
THere are three types of protein folding mechanisms: |
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Term
signal peptide signal recognition protein |
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Definition
| Membrane proteins are targeted and assisted in membrane insertion by a ______ _______ sequence and ______ ___________ _______(SRP). |
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Term
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Definition
| Protein folding and unfolding are ___________ processes. |
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Term
FALSE- proteins are easily unfolded * unfolded protein is favored unless other forces bring protein parts together. |
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Definition
True or False? Proteins are difficult to unfold once they've finished folding. |
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Term
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Definition
| Proteins are stabilized by the sum of a very large number of ____, ___-________ interactions. |
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Term
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Definition
| The hydrophobic effect drives partial protein _______. |
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Term
H-bonds ion pairs other weak interactions (van der waals etc...) metal binding (Ca, Cu, Zn, Fe, others) |
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Definition
Proteins can be further stabilized by these four sources: |
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Term
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Definition
| Protein hydrophobic effect mimics _______ formation. |
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Term
Metal ion coordination disulfide bond hydrophobic interaction hydrogen bonding electrostatic attraction |
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Definition
| Some examples of weak interactions. |
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Term
Promotor LacZ gene (beta-galactosidase) LacY gene (beta-galactoside permease) LacA gene (beta-galactoside transacetylase) |
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Definition
| The lactose operon is made of four regions: |
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Term
INACTIVE ACTIVE glucose cAMP |
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Definition
| The operon is ________ without lactose. The operon is ______ when lactose is present. Transcription of the lac operon will only occur at a high level is _______ levels are low (meaning ____ levels are high). |
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Term
Methylation Phosphorylation Acetylation |
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Definition
Genes can be silences through chromatin modifications (3): 1- marks heterochromatin and silenced genes 2-marks chromosomes for condensation 3- marks transcribed genes |
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Term
BASAL GC box CAAT box TATA box |
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Definition
| _____ expression involves two upstream elements and one proximal element. The first upstream element, __ ___ is bound by SPI and the other upstream element, ____ ____ is bound by CTF. The proximal element, ____ ___ is bound by TFIID. |
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Term
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Definition
| Regulated expression involves _________ and __________. |
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Term
less yeast less *e.coli (3-5 min) *yeast (22 min) *mammals (10 hrs) |
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Definition
mRNA half-lives vary significantly for different mRNAs and organisms. t1/2 of e.coli is _______ than the t1/2 of _____ which in turn is _______ than the t1/2 of mammals. |
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Term
IRE-BP transferrin ferritin IREs IRE |
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Definition
mRNA translation can be regulated by iron status: a deficiency in iron causes ______ to be activated. Once activated, it will prevent mRNA degradation of the ___________ recepter mRNA, which it recognizes by the large amount of ____ on the sequence, and it will inhibit translation of ________ mRNA (which it recognizes by ONE ___ on the mRNA). |
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Term
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Definition
| _____ mRNA produced in the liver is translated into the ___-____ protein, but the same mRNA is edited, deaminating ac to au in intestinal cells to make a stop codon and the protein produced is ________. |
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Term
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Definition
| ____________ is the study of chromosomes and their abnormalities. |
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Term
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Definition
The frequency of live births with chromosome abnormalities which lead to disease is ______. |
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Term
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Definition
| Chromosomal abnormalities are the leading cause of ______ ___________ and pregnancy loss seen in ___ of the first trimester spontaneous abortions and ___ of the second trimester spontaneous abortions. (%) |
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Term
| Chiasma (occur in prophase I) |
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Definition
| _______ between homologous chromosomes allow for genetic exchange to occur via crossing over. |
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Term
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Definition
| _______ _________ causes a net gain of info on one chromosome and loss of info on the other. |
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Term
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Definition
| ________ recombination causes gene (DNA) gains and losses. |
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Term
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Definition
| Transposable elements or _______ _____ may use ___ sequences to target insertion sites where mutations could occur. Some viral DNA take advantage of this to integrate their DNA into chromosomal DNA. |
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Term
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Definition
| A minimun of __-__% of all conceptions have chromosomal abnormalities. __% of those are trisomies, __% are monosomes and __% end up being triploids. |
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Term
karyotypes Acrocentric Submetacentric Metacentric |
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Definition
Chromosomes are sorted in __________ by size and shape. Chromosomes are further classified byt the position of the centromere: ___________= centromere near tip ____________= centrome between middle and tip ____________= centromere near middle |
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Term
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Definition
Short arm of a chromosome is labeled _, and the long arm is labeled _. Band numbering is from __________ to tip. |
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Term
G-banding (giemsa stain) Q-banding (quinacrine stain fluorescent) band region long 14 |
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Definition
2 ways to stain chromosomes? Nomenclature? 14q32 Implies second ____ in ____ 3 on the ___ arm of chromosome __. |
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Term
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Definition
| __________ means possessing a complete set of extra chromosomes. __________ means not containing a multiple of 23 chromosomes (for humans). |
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Term
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Definition
| Polypoid abnormalities are common in _____ cells, but are rare in humans. |
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Term
1/10000 15% fertilization of egg by two sperm |
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Definition
Sex chromosome triploidy (XXX, XXY or XYY) is seen in ____ live births, but nearly all __% of conceptions with this abnormality are spontaneously aborted. Survivors die soon after birth. Most common cause? |
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Term
Trisomy 21 down 1/800 1/1000 |
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Definition
| _______ __ is the most common trisomy in live birthds and causes ____ syndrome. The frequency is _____ to ______. |
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Term
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Definition
| __% of down syndrome patients live to age 10 and __% of them live to age 50. |
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Term
Edward's Patau 1/6000 1/10000 live births 5 |
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Definition
There are two less common trisomies: Trisomy 18 (________ Syndrome) and Trisomy 13 (_____ syndrome). Trisomy 18 has a frequency of ______ and trisomy 13 of _______. For each of these only about _% survive past 12 months. |
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Term
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Definition
| ___ chromosome aneuploidy is more common than trisomy. _____ males to _____ females. These are survivable unless no _-chromosome is present. |
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Term
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Definition
| Turner sydrome karyotype 45 __, has a freqency of _______ to ________. |
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Term
Reciprocal (mutal exchange) Robertsonian (loss of short arms and fusion at centromese fo the remaing long arms into one chromosome- this can only occur with the acrocentric chromosomes- 13-15, 21 and 22) |
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Definition
| There are two types of translocations: |
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Term
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Definition
| _________ are losses of one or more bands. _________ are losses of chromosome regions too small to be detected by traditional clinical cytogenetics. |
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Term
1- recognizable chromosome features (down s.) 2- unrecognizable pattern of 2+ malformations. 3- ambiguos genitalia 4- MR or developmental delay in children with multiple physical abnormalities. 5- children with parents with chromosome abnormalities. 6- females with short stature and primary amenorrhea 7- males with small testis or significant gynecomastia 8- stillborns with malformations or not recognizable reasons for fetal death. |
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Definition
| Indications for performing chromosome analysis?(8) |
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Term
Somatic oncogenes tumor suppressors |
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Definition
| Many cancers are associated with chromosome rearrangements within _______ cells. Rearrangements causing cancer often involve altered expresson of _________ or _____ ___________. |
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