bio final review

what promotes the expression of the gene

enhancers

what do activator proteins bind to

enhancers

what are enhancers

DNA sequences that enhance gene expression

what are activator proteins

the specific transcription factors that bind to those enhancers

what do silencers do

silence the expression

if DNA is open

euchromatin

if DNA is packaged and condensed

heterochromatin

Which one is likely to be transcriptionally active?

euchromatin

proof of genomic equivalence

animal cloning

what controls gene expression

transcriptional regulators

do activator proteins promote or decrease transcription

promote

what do repressor proteins bind to

silencer DNA proteins

do repressor proteins promote or decrease transcription

decrease

what do micro RNAs (miRNA) act as

they act as a guide for the risc complex (the RNA induced silencing complex) to inhibit translation of the messenger RNA

Recombinant DNA Technology

The isolation of a selected piece of DNA from a chromosome and the amplification, sequencing, and modification of this DNA.

Restriction Endonucleases

cut DNA at specific sites (ends can be blunt or sticky)

what is a plasmid

a circular piece of DNA that is used for cloning

what is the role of DNA ligase

allows us to take fragments of DNA and fuse them together

most enzyme sequences are

palindromes (same thing backwards… ex: mom, racecar)

what can separate DNA fragments based on size

gel electrophoresis

why is DNA negatively charged

because of the phosphates on the backbones

What is the purpose of providing a current through the gel?

the DNA gets pushed through the gel matrix and goes from the negative pole to the positive pole

We often insert DNA fragments into

plasmids

Which fragments – larger/small – move faster through the gel?

smaller fragments

what makes a plasmid recombinant

it contains DNA from different sources

what do these recombinant plasmids do

transforms bacteria which expands the number of cloned fragments of DNA

Template DNA is mixed with the ingredients required for DNA synthesis which are…

-nucleoside triphosphates
-primers
-a special polymerase, called Taq

step 1 of The Polymerase Chain Reaction (PCR)

Pull DNA strands apart by raising the temp.

step 2 of The Polymerase Chain Reaction (PCR)

Allow primers to bind to their target sequence by lowering the temperature.

step 3 of The Polymerase Chain Reaction (PCR)

Synthesize DNA by raising the temperature again to the enzyme’s active temperature.

paracrine and autocrine signaling

cells signal to neighboring cells (paracrine)

cells signal to themselves (autocrine)

endocrine signaling

hormones travel through the bloodstream to cells at a distance

synaptic signaling

localized neurotransmitters can mediate long-range signals

contact dependent signaling

membrane bound signaling factor and receptor bind to each other

what are steroid hormones derivatives of

cholesterol (hydrophobic)

what do hydrophobic signaling molecules bind to

nuclear receptors

Ion-channel-coupled receptors

Signaling molecule induces a conformational change in the
receptor, thus allowing select ions to cross the membrane

Enzyme-coupled receptors

The cytoplasmic domain of the receptor has enzyme activity
or binds to an enzyme

G-protein-coupled receptors (GPCRs)

The receptor is linked to the activation/inhibition of a
downstream protein by a GTP-binding protein (G-protein)

how do G proteins work

G-proteins often activate enzymes that produce second messengers which are small diffusible intracellular molecules

Two examples of G-protein-coupled enzymes

-Adenylyl Cyclase produces cyclic AMP (cAMP) from ATP
-Phospholipase C produces IP3 and DAG

what does IP3 do

released into the cytosol and will turn on the release of calcium from the ER

what is the primary goal of the cell cycle

to replicate DNA and segregate chromosomes to identical daughter cells

how many phases does the cell cycle have

4

Interphase

cell replicates its DNA

centromere

the constricted region holding the chromatids together

nucleus divides vs cell divides

karyokinesis vs cytokinesis

what is the mitotic spindle made up of

microtubules (cytoskeleton)

what is the centrosome

the microtubule organizing center

what are kinetochores

protein complexes linking the spindle to the centrome

prophase (mitosis)

spindle begins to form and chromosomes condense

prometaphase (mitosis)

nuclear envelope breaks down and spindle binds to the chromosomes

metaphase (mitosis)

chromosomes line up at the equator (metaphase plate)

anaphase (mitosis)

chromosomes separate and are pulled to the spindle poles

telophase (mitosis)

chromosomes arrive at the spindle poles, nuclear envelope develops around each new nucleus, and the contractile ring begins to develop

cytokinesis (mitosis)

the cytoplasm is divided, and the actin/myosin contractile ring pinches the cell to form two daughter cells

what are cell cycle transitions controlled by

cyclin-dependent kinases

when are CDKS activated

when they bind cyclins

Chromosomes pair together and switch some genetic material by crossing over during

prophase 1

A crossover event is observed as a

chiasma

Homologous chromosomes pull away from each other at

anaphase 1

Sister chromatids pull away from each other at

anaphase 2

Nondisjunction

the failure to separate homologs properly

diploid

when a cell has two copies of the chromosomes

gametes

sperm or egg

fertilization

when sperm and egg fuse together

zygote

single cell which we are derived

If a promoter becomes heterochromatin, would that increase or decrease transcription?

decrease

Which of the following is not true of DNA gel electrophoresis?

DNA fragments are separated from each other based on their differences in charge

Which type of cell signaling does not require the release of a secreted molecule and is used for very localized signaling events

contact dependent

A signal that must be relayed to the entire body is most efficiently sent by _________________________ cells, which produce signaling molecules that are carried throughout the body through the bloodstream

endocrine

aneuploidy

wrong chromosomal complement