Biochemistry Test 2: Gene Expression And Regulation

Front 1

DNA Transcription steps

Back 1

1. Binding of DNAp to promoter
2. Initiation of transcription
3. Elongation of transcription
4. Termination of transcription

Front 2

Requirements for RNA synthesis

Back 2

1. a 2 stranded DNA template
2. DNA dependent RNAp
3. 4 nucleoside triphosphates
4. Mg

Front 3

Holoenzyme

Back 3

A catalytically active enzyme with all its subunits

Front 4

RNAP 1

Back 4

#1 gives the large stuff

Forms the ribosome components 5.8s,28s, and 18s.

Front 5

RNAP 2

Back 5

2 m's 1 s and gives the protein editors

Synthesizes precursors of mRNA, snRNA and miRNA

Front 6

RNAP 3

Back 6

Forms the 5s rRNA and tRNA. Also has a signal recognition site and implicated in RNA splicing.

Front 7

Stages of RNA synthesis and what is the primer for the start sequence?

Back 7

Binding, initiation, elongation, and termination.
No need for a primer the start site is always a GGG or AAA.

Front 8

DNA primer

Back 8

Short strand of RNA produced by primase.

Front 9

RNA promoter

Back 9

Promote the gold cone and Cat parties of RNA

GC(-110) and CAAT(-40) sequences are used to start RNA transcription in addition to the TATA box

Front 10

Transcription stop signal

Back 10

A rapid folding in the newly synthesized RNA chain can cause this like an anchor dropping off a ship.

Front 11

Prokaryotic v Eukaryotic translation

Back 11

Prokaryotes can transcribe and translate at the same time because they don't have any introns and no need for mRNA modification.
Eukaryotes need post translational modifications like capping and introns splicing before they can translate.

Front 12

hnRNA

Back 12

Unprocessed prescursor mRNA that is still in the nucleus.

Front 13

Transcription factors

Back 13

Controls the drafting of mRNA soldiers. TF3 give 5s rRNA. TF2D give TBP.

A protein that binds to a specific site in DNA and controls the transcription of information.
TF 3 gives rise to 5s RNA.

Front 14

Enhancer sequences

Back 14

They increase the rate of transcription and can be located far away from their site of action.

Front 15

Zinc finger protein

Back 15

A family of proteins that bind to DNA. Many TFs use this motif. Cys and His residues bind to Zn

Front 16

TATA box and starting protein translation

Back 16

Initiation begins with the recognition of this site by TBP(TATA binding protein)
TBP is part of TF2D

Front 17

Poly A tail making signal

Back 17

AAUAAA on mRNA signals this addition.

Front 18

Introns and cleavage

Back 18

Introns all start with GU at the 5' end and and with AG at the 3' end. snRNPs recognize these cleavage sites and make up the Spliceosome. These are rich in uridine.

Front 19

Spliceosomal cleavage

Back 19

Recognizes the GU/AG sites and cleaves. Each end forms a 2'-5' phospodiester linkage loop at the branch site. The two exons are joined and the spliceosome releases.

Front 20

Lupus

Back 20

Antibodies to snRNPs block slicing of introns and proteins aren't formed.

Front 21

Constituitive enzymes

Back 21

Enzymes that are always present, they do the general housekeeping of the body.

Front 22

What is the normal concentration of Induced enzymes?

Back 22

Present in low amounts and then increase when needed

Front 23

Enzyme repression

Back 23

Enzymes not synthesized unless needed

Front 24

Ioerib

Back 24

Complete regulatory unit of a set cluster of genes, they include the structural components of the genes.

Front 25

Repressor genes

Back 25

The control units of genes. When substrates are bound here transcription is inhibited.

Front 26

Lac operon

Back 26

Produces lactose metabolites. Inhibited in the presence of glucose. Induced when allolactose binds to the repressor and allows transcription.

Front 27

Lactose proteins.

Back 27

Beta-galactosidase breaks down lactose into glucose and galactose. Permease is created and inserted into the cell membranes to allow lactose to pour into the cell. Once the lactose concentration is reduced enough, the repressor will be able to bind again to the lac operon and synthesis of these two proteins is inhibited.

Front 28

Alternative splicing

Back 28

The poly A tail can be added to different sites of the mRNA and that creates different versions of translational models.

Front 29

RNA editing

Back 29

Is like typing a different chemical onto RNA

Information in RNA is altered through a chemical change, This could be a Cyt to Val deamination.

Front 30

What sequences of mRNA are unstable?

Back 30

AUUUA sequences are unstable and can lower the half life of mRNA

Front 31

miRNA

Back 31

Regulates mRNA soldiers the same way siRNA does.

Functional in gene regulation and medicinal purposes. Forms a partly double stranded RNAs with mRNA in order to inhibit or initiate processes. At the point of hybridization the miRNA puts on a target for Dicer that cleaves the mRNA.

Front 32

siRNA

Back 32

Block and kills mRNA sequences

Silencing or interfering RNAs form a long double stranded RNA that inhibit the expression of genes by setting up sites that target mRNA for degradation