Cell Biology

Point mutations affect a _ nucleotide pair

The sum of all an organism's genetic instructions

The expression of DNA in cells determines their _

A lot of supposedly "junk" DNA is actually _

_ DNA determines when genes are expressed and to what extent

Mutations in a gene's _ region or on its regulatory sequence can alter its _

A mutation may or maybe not change the amino acid sequence, because amino acids have _ coding sequences

When gene duplication occurs, it gives rise to multiple _ of a gene, and _ can occur without adverse consequences

Genes that are inactivated by mutation become _

Mammalian 4-subunit hemoglobin arose from ancestral _ made up of a single _

4-chain globin binds 4 _ molecules in a cooperative way

Whole genomes can sometimes be duplicated, allowing _ to create new genes

Exon shuffling generates proteins with new combinations of protein _

In which switching exons around via breaks in introns can recombine exons

The regulatory element of a gene; tells it where/whether to express

_ gene transfer occurs between organisms of different species, especially bacteria

Mutation rate is _ for every part of a genome, but _ causes some parts of a genome to evolve faster than others

Mutations within a genome, in a regulatory region, duplication, or exon shuffling can cause major _ changes

Some parts of a genome remain highly conserved through time; for instance _ from widely separated spp have very similar nucleotide sequences

"Eukaryotic genome" usually refers to _ DNA

A diploid human nuclear genome is about _ billion base pairs long

Under an electron microscope, unwound _ resembles beads on a string

DNA is wound twice around the _ core

The histone core is made up of 4 types of proteins: _, _, _, _; with 2 of each for a total of _

The family of different histones was created by gene duplication and _

Further compaction on the DNA wound into a "string of beads" produces the familiar mitotic _

The net result of DNA being compacted into chromosomes: each chromosome is _x shorter than its extended length

Chromatin remodeling makes regions of DNA accessible for _

Chromatin _ makes regions of DNA accessible for transcription

Chromatin remodeling is performed by the remodeling _, via catalysis of _ sliding

Chromatin remodeling is performed by the _ complex, via _ of nucleosome _

A _ code signals changes in the state of the chromatin

A histone code signals changes in the state of the _

The degree of condensation of _ varies at different phases of the cell's life cycle

During interphase, is the cell dividing?

During metaphase, _ is in its most highly-compacted state, forming individual _

The degree of condensation of chromatin is different at different places along the same _

Entire chromosomes can be _

Patterns of histone modification can be _

Patterns of _ modification can be inherited

Gene silencing & _ causes cell _ via a specific histone code

Gene _ & activation causes cell differentiation via a specific _ code

_ opens a chromosome by attaching to the tails of the amino acid

Acetylase opens a chromosome by attaching to the tails of the _

_ closes a chromosome

De-acetylase _ a chromosome

Each time a cell _, the DNA must be copied exactly

1 replication bubble consists of 2 replication _

1 replication _ consists of 2 replication forks

DNA replication is carried out by the enzyme _

DNA _ is carried out by the enzyme DNA polymerase

During replication, the DNA helix is opened up by the enzyme _

As the DNA helix is opened up, topological distortion is relieved by enzymes called _

As the DNA helix is opened up, _ distortion is relieved by enzymes called topoisomerases

Topological distortion is also called _ stress

Torsional stress is also called _ distortion

As the DNA helix is opened up, single-strand DNA-binding _ bind to the separated DNA strands

The first step of DNA synthesis involves the synthesis of a _ by an enzyme called _

The primer in DNA synthesis is a piece of _ with _ on the 3' end for the DNA _ to attach to.

A _ polymerase always "checks its work"; a _ polymerase doesn't

A DNA polymerase always "checks its work", because the consequences of a _ are more severe for errors in DNA

A DNA _ always looks at the previous _ to make sure it's correct

A _ marks the end of the RNA primer, indicating to the DNA polymerase when DNA _ should start

During DNA synthesis, a _ acts like a seatbelt to keep the DNA polymerase on the template

Short, newly synthesized DNA fragments that are formed on the lagging template strand during DNA replication

Younger chromosomes are _; germ cell lines do not shorten with time, but somatic cells do because they lack the _ enzyme

Younger chromosomes are _; germ cell lines do not shorten with time, but somatic cells do because they lack the _ enzyme

Somatic chromosomes lose information at the end of the linear DNA molecule when the _ is removed

The _ limit is the point at which a population of cells suddenly stops dividing due to degradation of their chromosome ends

Telmoerase is an enzyome that prevents generational _ of a chromosome

Telomerase adds a repeating pattern to the end of the chromosome, but this is not expressed in _ cells

Germ cell lines, and also many _ cells express telomerase, and can thus divide _

In order to prevent mistakes, a DNA polymerase can _ itself, by using proper _ to determine whether bases have paired correctly

_ activity removes a mispaired nucleotide; a _ inserts the correct nucleotide via _ activity

_ repair uses mechanisms for fixing mistakes after DNA has already been replicated

Removal of a mismatched DNA strand is carried out by a DNA mismatch _, which folds the strand and _ the mismatched side

The DNA mismatch repair protein has to figure out which is the original strand; in bacteria, the original is _

Defects in mismatch repair lead to _ in the number of unrepaired errors in DNA; accumulation of errors in genes for cell div. can lead to _

_ is a form of colon cancer that is associated with defects in mismatch repair proteins

HNPCC is a form of colon cancer that's associated with defects in _ proteins

DNA can be damaged by _, chemicals like _ (car exhaust & cigarette smoke), and spontaneous chemical _ in a cell

A common form of UV radiation damage to DNA occurs when two adjacent thymines form a thymine _

The addition of a bulky group such as _ can cause distortion of the DNA helix

Water molecules can cause the NH3 group on Cytosine to become _ via deanimation

Water molecules can cause the NH3 group on Cytosine to become Uracil via _

Water molecules can cause the NH3 group on _ to become Uracil via deanimation

Cells use _ mechanisms to fix damage to DNA

During excision repair, the damage region of DNA is excised, and the _ makes a new top strand using the bottom strand as a template

After excision repair is complete, a _ seals the nick in the new strand

The lack of a functional nucleotide excision repair system can cause problems, such as extreme sensitivity to _ light

The first step in transcription is the binding of a _ to the promoter

The first step in transcription is the binding of an RNA polymerase to the _

In prokaryotes, signals in the DNA sequence tell the _ where to start and stop copying

The promoter regions of prokaryotic genes have consensus sequences at _ and _ bp, counting back from the star of transcription

The promoter regions of prokaryotic genes have _ sequences at -10 and -35 bp, counting back from the star of transcription

In the presence of enzymes that chew up sequences not associated with proteins, on the -10 and -35 regions remain, meaning they're bound by

The _ factor "ushers" the RNA polymerase into place

The sigma factor "ushers" the _ into place

After the termination and release of the RNA polymerase and new DNA chain, the _ rebinds to the polymerase

In eukaryotes, RNA polymerase I makes _ RNAs

In eukaryotes, RNA polymerase II makes _ RNAs

In eukaryotes, RNA polymerase III makes _ RNAs

_ factors are proteins that help eukaryotic RNA polymerases find transfer start sites & initiate RNA synthesis

General transcription factors are proteins that help eukaryotic _ find transfer start sites & initiate RNA synthesis

General transcription factors are proteins that help eukaryotic RNA polymerases find _ & initiate RNA synthesis

General transcription factors are proteins that help eukaryotic RNA polymerases find transfer start sites & initiate _

TFII is the transcription factor for _

_ is the transcription factor for RNA polymerase II

TFII is the _ for RNA polymerase II

The _ box is 25 bp upstream of the start of transcription

The TATA box is 25 bp upstream of the start of _

"_ elements" such as the GC box or the CCAAT box are within 100 bp of the start of transcription

Binding of the _ to the TATA box starts assembly of the basal transcription complex

Binding of the TFIID to the _ box starts assembly of the basal transcription complex

Binding of the TFIID to the TATA box starts assembly of the _ complex

_ of the tail of the RNA polymerase by TFIIH triggers transcription initiation

Phosphorylation of the tail of the _ by TFIIH triggers transcription initiation

Phosphorylation of the tail of the RNA polymerase by _ triggers transcription initiation

Phosphorylation of the tail of the RNA polymerase by TFIIH triggers _

General _ factors & RNA polymerase make up the basal transcription complex, also called the transcription initiation complex

General transcription factors & _ make up the basal transcription complex, also called the transcription initiation complex

General transcription factors & RNA polymerase make up the _ complex, also called the transcription initiation complex

General transcription factors & RNA polymerase make up the basal transcription complex, also called the _ complex

In prokaryotes, the _ sequence allows a ribosome to correctly recognize the site to start translation

In eukaryotes, the _ allows a ribosome to correctly recognize the site to starttranslation

tRNAs contain a _ with sequence that interacts with mRNA

_ contain a hairpin loop with sequence that interacts with mRNA

tRNAs contain a hairpin loop with sequence that interacts with _

An _ compliments & recognizes a codon on an RNA sequence

_ catalyze the linkage of the appropriate amino acid to its conjugate tRNA

Aminoacyl tRNA synthetases catalyze the linkage of the appropriate _ to its conjugate _

_ is required to initiate translation; it moves along RNA searching for the first AUG codon;the large ribosomal subunit RNA binds to it

Initiator tRNA is required to initiate _; it moves along RNA searching for the first AUG codon;the large ribosomal subunit RNA binds to it

Initiator tRNA = required to initiate translation; it moves along RNA searching for the first_; the large ribosomal subunit RNA binds to it

Initiator tRNA is required to initiate translation; it moves along RNA searching for the first AUG codon; the _ binds to it

The _ factor ends polypeptide synthesis by recognizing the stop codon

The release factor ends _ by recognizing the stop codon

The release factor ends polypeptide synthesis by recognizing the _

In bacteria, several genes may be controlled by a single _; a group of genes like this is called a _

The _ encodes 3 proteins needed to use lactase

An _ is the binding site for a repressor protein, which prevents the expression of a gene

An operator is the binding site for a _ protein, which prevents the expression of a gene

A _ protein prevents the transcription of a gene by preventing a polymerase from binding to the operator

A repressor protein prevents the _ of a gene by preventing a polymerase from binding to the _

Transcription in prokaryotes is helped by the binding of _ to a _-binding site

CAP-dependent genes need a CAP on the _

In eukaryotes, general transcription factors plus the RNA polymerase at the _ box make up the _ complex

In eukaryotes, the amount of transcription from a given promoter depends on the _ & _ with whichthe _ complex assembles at the promoter

_ are short DNA sequences outside of the promoter that control transcription of genes

Enhancers are short DNA sequences outside of the promoter that control _ of genes

A _ binds the enhancer, then DNA _ brings both to the _ complex

The _, _, & _ are all DNA sequences that are necessary for initiation & regulation of transcription

The enhancer, promoter, & operator are all DNA sequences that are necessary for initiation & _ of _

After transcription, the newly-made RNA, called the _ must be processed

Messenger RNAs are processed in _ cells but not _ cells

_ must be removed from the primary transcript

In eukaryotic cells, splicing proceeds via a _ intermediate, performed by _