Biol1020 Final Exam

gene regulation

refers to the ability of cells to control their level of gene expression

ensures proteins produced at the correct time and amount

reason the majority of genes are regulated

energy

gene regulation saves ------- by producing only when needed

constitutive genes

unregulated and have essentially constant levels of expression

gene regulation

the process by which many enzymes in the body are regulated

beta galactosidase

breaks down lactose in gene regulation

lactose permease

transports lactose into the cell

translation

proteins are created during

post- translation

functional proteins are created during

Transcription in bacteria

involves regulatory transcription factors; bind to DNA in the vicinity of a promoter and affect transcription of one or more nearby genes

repressors

inhibit transcription

negative

repressed have ------- control

activators

increase the rate of transcription

positive

activators have -------- control

repressors

block the RNA polymerase

effectors

can be a repressive or activator

operon

a cluster of genes under transcriptional control of one promoter

operator

regulatory region of gene regulation

mRNA

transcription results in ------- that are translated into several proteins

transcription

allows coordinated regulation of a group of genes with a common function

no lactose

repressor blocks the RNA polymerase

lactose present

RNA polymerase is not blocked; transcription occurs

DNA Binding

bulk of protein blocks DNA; coiled structure makes it strong

prokaryotic

operons only found in -------------- cells

examples of transcriptional control

DNA packing, transcription factors, coordinate genes

DNA packing

can limit which genes can be transcribed; wrapped genes cannot be used

eukaryotic cells

has no operons; genes regulated individually; regulation usually more complicated

transcription factors

activators proteins and enhanced sequences

TATA Box

starting point for transcription

Preinitiation complex

an enhancer is bound to an activator

mediator

mediated between pre initiation complex, the activators, and repressors

activators and repressors

bind to transcription factors

faster initiation

activators stimulate mediator by allowing

RNA polymerase II

depressors inhibit mediators so ----------------------- cannot transcribe gene

coordinated genes

several genes regulated together but not located next to each other

mRNA

can last for hours, days, or even weeks

insulin

example of protein activation

model organism

have qualities that make them convenient to test with

metamorphosis

frogs go through

relative position

each cell in the body must become the right cell type based on its -------- ------

division, migration, apoptosis, differentiation

cell may respond by

death

what does apoptosis mean

induction

contact between cells triggers a switch in developmental paths

homeobox genes

direct the formation of many body structures during early embryonic development

allometric growth

changes in the shape of the bones

viruses (viroids)

non living particles with nucleic acid genomes that require the assistance of living cells to reproduce

tobacco mosaic virus

first virus discovered

bacteria

viruses smaller than

protein coat

nucleic acid enclosed in a

4000

over ----- types of viruses

host, range, structure, genome

viruses vary greatly in (4 factors)

capsid

The protein shell that encloses a viral genome.

capsomeres

capsids are built from protein subunits called

capsid

can have a variety of structures

phages

are more complex viruses

accessory structures

some viruses have them; they help them infect hosts

viral envelopes

surround the capsids of influenza viruses and many other viruses found in animals

viral and host cell molecules

viral envelopes contain a combination of

host range

many species and cell types can be infected

structural

all viruses have a capsid but it varies in shape and complexity

genome

DNA vs. RNA; linear vs. circular

alive

viruses are not

attachment

phage binds specifically to proteins

lysogenic cycle

creates many copied bacteria; wants to reproduce not kill their host

membraneous envelope

many viruses that infect animals have a

viral glycoproteins

-------------- on the envelope envelope bind to specific receptor molecules on the surface of a host cell

host cell plasma

some viral envelopes are derived from the

macromolecules

viruses evolved from ----------- inside living cells (theory)

viroids

composed solely of a single stranded circular RNA molecules

plant

viroids infect ------- cells

prions

composed entirely of protein, infectious agent; almost indestructible

transduction

viruses that infect bacteria transfer bacterial genes from one bacterium to another

selective breeding

example of traditional genetic improvement

selective breeding

breeding out undesirable qualities; happens in plants and animals

back crossing

introducing new traits

Recombinant DNA technology

cutting out one gene, placing in new organism

plasmids

circular DNA fragments; carry extra genes

transformation

take up DNA pieces from environment

transduction

transfer of bacterial genes by a virus

conjunction

two bacterial exchange DNA through pilus

Restriction endonucleases

recognize speak dna sequences

recombinant plasmids and recombinant viruses

vectors in prokaryotic cells

probes, electroporation, gene gun

vectors in eukaryotic cells

reporter gene

linked to same promoter as foreign gene

7000

over ----- human disorders are caused by mutations in single genes

gene therapy

injecting genetically engineered cells into a person to repair a genetic disorder

glyphosate

herbicide resistance; resistance to-------

enriched

wheat flour is ------ not genetically engineered

rice

not easy to enrich

iron and vitamin A

golden rice is engineered with extra

edible vaccines

common foods containing vaccines against common diseases

bananas and tomatoes

edible vaccines placed in

hormone treatments

milk and beef production use

enviropig

reduced phosphorus in water

lactose operon

requires the presence of lactose before it is turned on

operator

if a repressor is active, it attaches to the ------- of an operons

introns

what parts of a eukaryotic messenger RNA strand are removed before translation takes place

Transcription

mRNA is created during

mediator, activator, effector

what is involved in the regulation of transcription

trigger developmental response

physical contact, diffusion of morphogens from one cells to another, and morphogen concentration gradients