Lecture 10: Dna To Protein

Front 1

Compare DNA & RNA

Back 1

DNA
double stranded helix, anti paralell, complimentary base pairs, backbone is sugar deoxyribose and phosphate, A T G C
RNA
single stranded, linear, shorter than DNA, sugar ribose and phosphate, A U G C

Front 2

DNA replication

Back 2

-Begins at the origin, and proceeds in both directions. -DNA gyrase relaxes supercoiling
-DNA helicase unwinds piece of DNA
-DNA Polymerase attaches to a primer, adds nucleotides and proofreads
-Leading strand undergoes continuous replication, needing only one primer
-The lagging strand is discontinuous, using multiple primers
-initiation: RNA polymerase attaches to promoter; causes DNA to separate
-first nucleotides laid down complementary to DNA template
-creates replication fork
-when Polymerase hits termination codon, it falls off, and releases RNA strand.

Front 3

Transcription of DNA --> RNA

Back 3

One language to another. Format change.
-RNA polymerase recognizes DNA promoter
-sequence melts a short piece of DNA & adds nucleotide
-ends at DNA termination sequence, causes disassociation
-DNA is released

Front 4

Translation RNA --> protein

Back 4

Initiation:
Translation of RNA to Protein: Ribosome attaches to mRNA. Starts at first AUG, called the P site. tRNA with UAC anti-codon will bind. Starting amino acid is methionine. At A site, tRNA will attach to mRNA. Peptide bond forms between amino acids on the tRNA by dehydration synthesis.
Elongation:
tRNA goes into E. site from P site. detaches from amino acid, moves ribosome down one codon. (translocation).
codon recognition: next tRNA attaches to A site of ribosome. Peptide bond formation.
Termination:
when ribosome reaches stop codon, no tRNA can fit. Components disassemble by releasing newly formed polypeptide chain.

Front 5

How genetic code can be used to convert the information encoded in mRNA into protein

Back 5

-code sequence stated in the mRNA is laid out
-Ribosome attaches and tRNA with anticodon
-its corresponding amino acid attaches and covalent bonds form between adjacent tRNAs forming proteins

Front 6

Lac operon model and explain how it controls the production of proteins

Back 6

-gene regulation: example of inducible control system -default is off state, and is covered by a suppressor.
-when inducer attaches to repressor, it causes a shape change and turns on a promotor that can be used to metabolize lactose when conditions are present.

Front 7

prokaryotic gene expression

Back 7

-transcription is polycistronic gene included on mRNA molecule, more than one gene.
-occurs in the cytoplasm
-ribosomes are a different size, 70s
-can have more than one ribosome attached to mRNA
translation can occur while mRNA is still being made

Front 8

Eukaryotic gene expression

Back 8

monocistronic; one gene at a time is transcribed

Front 9

leading strand

Back 9

synthesized continuously in the 5′→3′ direction

Front 10

lagging strand

Back 10

synthesized discontinuously in the 5′→3′ direction

Front 11

DNA polymerase

Back 11

enzyme that synthesizes DNA; one strand as a template to make the complementary strand

Front 12

RNA polymerase

Back 12

enzyme that catalyzes the synthesis of RNS using a DNA template

Front 13

mRNA

Back 13

messenger RNA

Front 14

rRNA

Back 14

ribosomal RNA

Front 15

tRNA

Back 15

transfer RNA, delivers the appropriate amino acid to the ribosome during translation

Front 16

genetic code

Back 16

code that correlates a codon to one amino acid

Front 17

codon

Back 17

set of three adjacent nucleotides that encode either an amino acid or the termination of the polypeptide

Front 18

stop codon

Back 18

does not code for an amino acid and is nto recognized by a tRNA; signals the end of a polypeptide chain

Front 19

anticodon

Back 19

sequence of three nucleotides in a tRNA molecule that is complementary to a codon in mRNA