Biochemistry Quick Facts

Front 1

which NTP have 3 bonds and which have 2

Back 1

G-C pairs have 3 bonds, A-T have 2 (O-NH2 and nH-H bonds form)

Front 2

which NTP bond to which in dna

Back 2

A bonds to T
G bonds to C

Front 3

G bands are...R bands are...

Back 3

1. G bands are rich in A- T nucleotide pairs; they stain dark.
2. R bands are rich in G-C nucleotide pairs; they stain light.

Front 4

histone proteins...

Back 4

* form a histone octomer
*are positively charged
*contain a high proportion of lysine and arginine

Front 5

heterochromatin is...
euchromatin is...

Back 5

10%, highly condensed, replicated late
80%, less condensed, replicated early

Front 6

chromosome replication occurs during

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s-phase of the cell cycle

Front 7

DNA polymerase copy in which direction and produce in which direction

Back 7

copy (read) DNA in 3to5, produced in 5to3

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DNA polymerase delta

Back 8

replicated the leading strand

Front 9

DNA polymerase alpha

Back 9

uses the RNA primer to synthesize DNA fragments called Okazaki fragements

Front 10

DNA repair enzyme..

Back 10

replaces the RNA primers with DNA

Front 11

DNA ligase

Back 11

joins DNA fragments

Front 12

the TELOMERE nucleotide ewquence is

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GGGTTA

Front 13

nuclease

Back 13

cleaves the ends to form double-helix

Front 14

AP endonuclease

Back 14

recognizes the site of the missing base and nicks the deoxyribose sugar phosphate

Front 15

phosphodiesterase...

Back 15

excises the deoxyribose sugar phosphate

Front 16

this enzyme recognizes and removes uracil from DNA

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uracil-DNA glycosidase

Front 17

recognizes pyrimidine dimer and excieses a 12-residue oligonucleotide that includes the dimer

Back 17

uvrABC enzyme

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integrase

Back 18

recognizes specific nucleotide sequences and cuts the viral DNA

Front 19

two types of transposable elements

Back 19

alu sequences, LINE-1 sequences

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transposase

Back 20

is a recombination enzyme similar to integrase. it cuts the transposable element at sites marked by inverted repeate DNA sequences that are 20 base pairs long

Front 21

methotrexate inhibits ...

Back 21

dihydrofolate reductase

Front 22

in sickle cell anemia a ___ is converted to ___

Back 22

glutamic acid is converted to a valine

Front 23

the gene prmotor DNA sequence...

Back 23

located near the gene upstream, is where RNA polymerase II and transcription factors assemble so that a gene can be transcribed into messenger RNA, contains a TATA box, CAAT box or GC box

Front 24

the gene regulatory (enhancer) DNA sequence ...

Back 24

located far away from the gene, upstream OR downstream, binds gene regulatory protins

Front 25

what are the four types of DNA binding proteins..

Back 25

homeodomain proteins, zinc finger proteins, leucine zipper proteins, and helix-loop-helix proteins

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homeodomainn proteins ...

Back 26

consist of three linked alpha helices which are arranged in a helix-turn-helix motif in helicies 2 and 3, helix 3 binds specifically to DNA segments that contain ATTA sequence

Front 27

zinc finger protein..

Back 27

has one alpha helix, contains one zinc atom bound to four cysteine amino acids, contains a hormone-binding region, a 70 AA long region near the zinc atom binds specifically to DNA segments

Front 28

lucine zipper protein...

Back 28

consistes of an alpha helix that contains a region in which every seventh amino acid is leucine, dimerization and formation of y-shaped dimer, 20 aa logn region that binds DNA

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helix-loop-helix protein

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short alpha helix connected by a looop to a longer alpha helix, loop allows for dimerzation

Front 30

the lac operon consists of three genes

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lac Z gene - beta-glactosidase
lac Y gene - lactose permase
lac A gene - thioglactosidase transacetylase

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RNA polymerase I...
RNA polymerase II...
RNA polymerase III...

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I: rRNA
II: mRNA, snRNPs
III: tRNA and 5S rRNA

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RNA capping is..

Back 32

addition of methylated guanine nucleotide to the 5' end

Front 33

RNA polyadenylation

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addition of repeated adenine nucleotides (poly-A tail) to the 3' end of the RNA transcript

Front 34

RNA splicing...

Back 34

is performed by snRNPs that are a complex of RNA and protein called a spliceosome

Front 35

this enzyme links an aminio acid to tRNA

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aminoacyl-tRNA synthetase

Front 36

this enzyme helps form the peptide bond between amino acids during translation

Back 36

peptidyl transferase

Front 37

start codon is

Back 37

AUG which coes for methionine

Front 38

the stop codoons are

Back 38

UAA, UAG, UGA

Front 39

RNA polymeras I transcribes

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rNA genes to form 45S RNA

Front 40

RNA polymerase iii TRANSCRIBES

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5s RNA

Front 41

the 40S subunit contains

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18S RNA

Front 42

the 60S subunit contains

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5S RNA, 5.8S RNA, 28S RNA

Front 43

the fibrillar center of the nucleolus contains

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pale-staining transcriptionally inactive DNA

Front 44

the dense fibrillar component is..

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dense-staining and contains transcriptionally active DNA, RNA polymerase I and 45S RNA

Front 45

the granular component of the nucleolus

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contains maturining riboslma precursors including 45S rna 5s rna, ribosomal proteins, RNA-binding protiens and snRNPSs

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silent mutaions can occur when...

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mutations occur in spacer DNA, introns, or the third nuclotide codon (sometimes)

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missense mutations

Back 47

occur when a change in a single nucleotide alters the codon so that one amino acid in a protein replaces another produce proteins with a compensated function

Front 48

no9nsense mutations

Back 48

occur when a change in a single nucleotide alters the codon and produces a premature stop codon and produce nonfuctional truncated proteins

Front 49

frameshift mutations

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occur when a deletion or an insertion of a single nucleotide alterse the codon and shifts the reading frame, and produce garbled proteins

Front 50

translocation mutations

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occur when a section of a gene moves from its original location to another location and may produce no protein

Front 51

RNA splicting mutations

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occur when a change in the nucleotdie at the 5' or 3' end of an intron alters the codon and changes the splice site

Front 52

an oncogene is...

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is a mutated proto-oncogene it encodes an oncoprotein that disrupts the normal cell cycle anc causes cancer

Front 53

a proto-oncogene

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is a normal gene that enoodes a protein that stimulates the cell cycle

Front 54

the mutation of ras proto-oncogene to oncogene occurs when..

Back 54

a glycine is replaced by a valine

Front 55

p53...

Back 55

is the anti-oncogene located on chromosome 17, encodes for the normal p53 protein (a zinc finger GRP) that causes the expression of targe genes whose gene products suppresses the cell cycle at stage G1 by inhibiting the activity of Cdk2-cyclin D and Cdk2-cyclin E

Front 56

G0 is

Back 56

the resting phase of the cell

Front 57

G1 is..

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between mitosis and the synthesis of DNA (RNA, protein, lipid, and carbohydrate syntehsis occurs), lasts 5 hours

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S phase

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DNA and chromosomal protein syntheisis occurs lasts 7 hours

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G2 phase..

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between DNA synthesis and M phase lasts 3 hours, ATP synthesis occurs

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stages of M phase...,

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a. Prophase
b. Prometaphase
c. Metaphase
d. Anaphase
e. Telophase
f. Cytokinesis

Front 61

the proteins families that control the cell cycle

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cyclin dependent protein kinases AND cyclins which form Cdk-cyclin complexes

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G1 checkpoint

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*occurs at the G1->ss phase transition
*cdk2-cyclin D and Cdk2-cyclin E mediate this transition
*the p53 anti-oncogene suppresses the cell cycle at this checkpoint preventing damaged DNA from entering S phase

Front 63

G2 checkpoint

Back 63

* occurs at the G2->m phase transition
* cdk1-cyclinA and Cdk1-cyclinB mediate this transition
* supresses the cell cycle at this checkpoint preventing damaged DNA from entering M phase

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cyclins are inactivated by ... during

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by protein deradation during anaphase of M phase, ubiquitin is covalently attached to the lysine residues of cyclin by the enzyme ubiquitin ligase, called polyubiquitination

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interphase...

Back 65

chromatin diffuse nucleus intact

Front 66

prophase (4 facts)...

Back 66

1. Chromatin condenses to form well-defined chromosomes.
2. Each chromosome is duplicated during the S phase and has a specific DNA sequence
(centromere) that is required for proper segregation.
3. A centrosome complex that acts as the microtubule organizing center (MTOC)
splits into two halves. The halves move to opposite poles of the cell.
4. The mitotic spindle, which contains microtubules, forms between the centrosomes.
5. nuclear envelope breaks down

Front 67

prometaphase

Back 67

1. The nuelear envelope is disrupted, giving the microtubules access to the chromosomes.
2. The nueleolus disappears.
3. Kinetochores (protein complexes) assemble at each centromere on the chromosomes.
4. Certain microtubules of the mitotic spindle bind to the kinetochores (kinetochore
microtubules) .
5. Other microtubules of the mitotic spindle are polar microtubules and astral
microtubules.

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metaphase

Back 68

1. Chromosomes align at the metaphase plate.
2. Cells can be arrested by microtubule inhibitors (e.g., colchicine).
3. Cells can be isolated for karyotype analysis.

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Anaphase

Back 69

1. The kinetochores separate, and the chromosomes move to opposite poles.
2. The kinetochore microtubules shorten.
3. The polar microtubules lengthen.

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Telophase

Back 70

1. Chromosomes decondense to form chromatin.
2. The nuclear envelope re-forms.
3. The nucleolus reappears.
4. The kinetochore microtubules disappear.
5. The polar microtubules continue to lengthen.

Front 71

Cytokinesis

Back 71

1. Cytoplasm divides through the process of cleavage.
2. A cleavage furrow forms around the center of the cell.
3. A contractile ring forms at the cleavage furrow. The ring is composed of actin and
myosin filaments.

Front 72

what are the gene products that are encoded by mitochondrial DNA (mtDNA)

Back 72

*Two ribosomal RNAs (rRNAs)
* 22 transfer RNAs (tRNAs) corresponding to each amino acid
* seven subunits fo teh reduced nicotinamide-adenine dinucleotide (NADH) dehydrogenase complex
* three subunits of teh cytochrome oxidases complex
* two subunits of the F0 adenosine triphosphate synthase
* One subunit (cytochrome b) of the ubiquinone-cytochorme c oxidoreductase complex

Front 73

teen falls while rollarblading and hurts his elbow. He can't feel the medial part of his palm.
What is the nn & what is the injury.

Back 73

ulnar nn due to broken medial condyle