question

Our genetic code is made up of DNA and are expressed in the phenotype as a __________.

answer

protein

question

What are the four characteristics of our DNA?

answer

Universal, unambiguous, redundant, non-overlapping & commaless

question

The genetic code consists of bases, these bases comprise _________.

answer

codons

question

The four bases are:

answer

A (adenine), T (thymine), C (cytosine), and G (guanine)

question

Since there are four bases, there are ____ possible codons

answer

64

question

DNA molecule is a double-helix- __________ _________.

answer

Rosalind Franklin

question

Meselson and Stahl experiment showed replication of DNA to be ________________.

answer

semiconservative

question

___________ unwinds the strand.

answer

helicase

question

_____________ ___________ sets up for the RNA primer

answer

RNA primase

question

_______ ___________ _________adds nucleotides to the 3’ end of the RNA primer and elongates the DNA strand

answer

DNA polymerase III

question

_________ __________ ___ removes the old RNA primer and replaces it with DNA

answer

DNA polymerase I

question

________ _________ catalyzes the formation of the phosphodiester bond linking the Okazaki fragments

answer

DNA ligase

question

___________ __________ action causes the newly forming leading strandto grow in the 5’-to-3’ direction

answer

DNA polymerase

question

________ uses DNA polymerases to repeatedly replicate DNA in the test tube.

answer

PCR (polymerase chain reaction)

question

RNA differs from DNA in 3 ways:

answer

1)it is single-stranded
2) its sugar molecule is ribose rather than deoxyribose
3) its fourth base is uracil rather than thymine

question

Messenger RNA =

answer

mRNA is the message or direction on how to make a protein

question

Transfer RNA =

answer

tRNA it matches up amino acids with the RNA message

question

Ribosomal RNA=

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rRNA used to bind the mRNA message

question

recognition sequence: one or two recognition sequences of 50 - 70bp form what?

answer

the TATA box

question

TATA box (rich in thymine & adinine): ___ base pairs upstream from the_____ ______ for transcription

answer

25; initiation site

question

_________ __________ _________ ___ needs transcription factors to initiate transcription

answer

Eukaryotic RNA polymerase II

question

The protein ______ binds to the TATA box

answer

TFIID

question

Finally _____ ______________ ____ binds to the site

answer

RNA polymerase II

question

_____ is transcribed from the DNA template after the ________ __ ____ are exposed by unwinding of the double helix.

answer

RNA;bases of DNA

question

RNA polymerase reads the DNA template strand from __ to __ and produces the RNA transcript from __ to __.

answer

3’ to 5’ ; 5' to 3'

question

Nucleotides are added at the __ end of the growing RNA

answer

3'

question

One mRNA codon _____ indicates the starting point of translation, also codes for _____________.

answer

AUG; methionine

question

Three stop codons indicate the end of _________.

answer

translation - UAA, UAG and UGA

question

The other 60 codons code only for __________ ________ _________.

answer

particular amino acids.

question

_____ binds the correct amino acid; has an _______ complementary to the mRNA codon.

answer

tRNA ; anticodon

question

The _____________, a family of activating enzymes, attach specific amino acids to their appropriate tRNA’s, forming ________ tRNA’s.

answer

aminoacyl-tRNA synthetases; charged

question

The ribosome is composed of two units:
large subunit that consists of _____ different molecules of rRNA and ___ different ________ ________ .
small subunit of one ___ ________ and ___ different protein molecules

answer

3; 45; protein molecules;rRNA molecule; 33

question

An initiation complex consisting of an _______ _________ __________ _________ and a small ribosomal subunit bound to mRNA triggers the beginning of ____________.

answer

amino acid-charged tRNA; translation

question

On the large subunit of the ribosome there are ___ sites to which tRNA binds.

answer

four

question

T (transfer) site: where ___________.

answer

tRNA first lands

question

A (amino acid) site is where the tRNA anticodon binds to ___________.

answer

binds to mRNA codon

question

P (polypeptide) site is where the tRNA __________.

answer

adds its amino acid to the growing poly peptide chain

question

E (exit) site is where tRNA, without its ______ _______, resides before leaving the________ and going back to the cytosol to pick up another ________ _________.

answer

amino acid; ribosome; amino acid

question

Polypeptides grow from the __ terminus toward the __ terminus. The ribosome moves along the mRNA ___ codon at a time.

answer

N to C; one

question

The presence of a _____ ______ in the __ site of the ribosome causes translation to terminate

answer

stop codon; A

question

Signals contained in the amino acid sequences of proteins direct them to___________ ____________.

answer

cellular destinations.

question

Modifications of proteins after translation include:

answer

proteolysis, glycosylation, and phosphorylation.

question

Cells must regulate how they synthesize molecules to suit their:

answer

condition, environment, and needs

question

cells can control synthesis activity by
___________ or controlling the production
of _________.

answer

regulating; enzymes

question

cells can control synthesis activity by blocking __________ of the gene that codes for a protein.

answer

transcription

question

cells can control synthesis activity by _______ the ______ after it is made.

answer

hydrolyze; mRNA

question

cells can control synthesis activity by ________ __________ of mRNA at the ribosome.

answer

preventing translation

question

cells can control synthesis activity by __________ the protein after it was made

answer

hydrolyzing

question

Point mutations result from alterations in______ ________ ________ of DNA.

answer

single base pairs

question

What are some examples of point mutation?

answer

silent, missense, nonsense, or frame-shift

question

Chromosomal mutations involve _______ regions of a chromosome.

answer

large

question

What are some examples of chromosomal mutations>

answer

deletions, duplications, inversions, or translocations

question

Point mutations result from the _______ or _______ of one base for another in the DNA and as a result in the RNA

answer

addition or subtraction;

question

Some result in no change in amino acid because of the redundancy of the genetic code=

answer

silent or synonymous mutation

question

A ____________ mutation results in an amino acid change

answer

missense

question

____________ mutation results in no protein being made at all, they are disruptive.

answer

nonsense

question

____________ mutation results in no protein being made at all, they are disruptive.

answer

nonsense

question

A _________-__________ mutation, is when single base pairs may be inserted or deleted from DNA

answer

frame-shift

question

___________ remove part of the genetic material

answer

deletions

question

___________ mutations are homologous chromosomes brake at different positions and then reconnect to the wrong partners

answer

Duplications

question

_________ mutations are removal of a segment and its reinsertion into the same location but flipped.

answer

Inversion

question

___________ mutation is when a segment of DNA breaks off and is inserted into a different chromosome

answer

translocation

question

Spontaneous mutations occur because of instabilities in ______ or _____________.

answer

DNA or chromosomes

question

Induced mutations occur when an ________ __________ damages ____.

answer

outside agent; DNA

question

Some of these non-transcribed regions are ________, such as the telomeres; some regulate ______ ________; and some have no known use.

answer

structural; gene expression

question

____________ are 5-50bps are repeated side by side up to a million times.

answer

Satellites

question

________ are 12-100 bps long & are repeated several thousand times. Can be used as ______ _______ for identifying an individual because their numbers can vary

answer

Minisatellites; genetic markers

question

__________ are 1-5bps present in small clusters 10-50 copies. These have been used in sequencing the human genome

answer

microsatellites

question

___________ are repetitive sequences at the ends of chromosomes

answer

telomeres

question

Chromosome _________ occurs after each round of replication. This leads to ____ __________.

answer

shortening; cell death

question

The enzyme_____________ prevents the loss of telomeric ends

answer

telomerase

question

A ___ _______ is added to the 5’ end.

answer

G cap, GTP

question

A _______ __ _______ is added to the 3’ end

answer

poly A tail

question

_______ _____________ particle binds at the 5’ splice site and a second binds near the 3’ splice site

answer

Small ribonucleoprotein (snRNP) particle

question

____________ elements move about the genome

answer

Transposable

question

a _____________ consists of two transposable elements flanking another gene or genes. The entire transposon is copied and inserted as a unit.

answer

transposon

question

If the insertion takes place in a somatic cell, _________ may result

answer

cancer

question

If a transposon replicates not just itself but also an adjacent gene, the result may be _____ _____________.

answer

gene duplication

question

Transposons can result in:

answer

cancer cells, gene duplication, genetic variability, new genes

question

___________ _______ are instructions that specify the primary structures of a protein molecule (those that get transcribed into mRNA)

answer

structural genes

question

_________ are units of transcription; structural genes plus regulatory mechanisms.

answer

operons

question

__________ regions bind activator proteins that stimulate the transcription complex (promoter then binds RNA polymerase & transcription starts)

answer

enhancer regions

question

_________ -when attached to an operon, transcription shuts down

answer

repressor

question

__________ are negative regulatory regions; turn off transcription by binding to repressor

answer

silencers

question

___________ blocks RNA polymerase from binding & transcribing the structural genes, preventing synthesis of tryptophan pathway enzymes

answer

tryptophan;

question

When glucose levels are high:

answer

1. RNA polymerase cannot bind efficiently
2. Structural genes are not transcribed. This is adaptive when the cell does not require an alternative energy source

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