bio exam 3

which DNA sequences are more alike

pair of sister chromatids

what would be the consequence if a cell underwent mitosis but not cytokinesis?

a cell with two nuclei would form

if this was caused by a malfunctioning motor protein, which one is likely not working

myosin

the passage of a cell through the stages of the cell cycle is controlled by protein kinases that phosphorylate many different proteins at appropriate times. what are these protein kinases called?

cyclin-dependent kinases

a daughter cell has too many chromosomes. what checkpoint failed? what stage of mitosis does this occur?

the spindle assembly

metaphase

after replication you are left with a daughter DNA molecule that contains many small pieces of RNA between long stretches of DNA. which enzyme, involved in replication, is likely malfunctioning?

DNA polymerase 1

if you start with one molecule of DNA, how many DNA molecules will you have after 3 rounds of PCR?

each round of PCR duplicates the present DNA, so we end up with 8 pieces of DNA

how do two properties of DNA fragments, size and charge determine how they move through a gel during gel electrophoresis?

DNA is negatively charged which causes it to be drawn towards the negative electrode in a gel setup, but the size of a DNA will determine how easily and therefore how fast the molecules can get through the porous gel.

why is the polymerase isolated from a heat-tolerant bacteria used when performing PCR

during the denaturation step of PCR, most polymerases would also denature as the DNA dissociates, but heart tolerant bacteria posses DNA polymerase that can survive the high temps

can PCR still be done without a thermo-style polymerase

yes, its a lot more labor intensive because you have to add new polymerase after each cycle

during sanger sequencing, why does the addition of nucleotides stop when a fluorescent nucleotide base pairs to the template DNA

the fluorescent nucleotides are ddNTPs meaning they do not have 3’ OH making it impossible to add another nucleotide onto it.

commonalities across cell division (11)

become large (make cytoplasmic factors) enough to divide into two

copy your DNA

prokaryote cell division

binary fission

asexual reproduction

eukaryote cell division

mitosis

meiosis

what is catalyzed by enzymes

DNA polymerase

conservative replication

DNA molecules contains either parent or daughter cells

semiconservative replication

each new DNA molecules contains one strand from the original (parent) and one newly synthesized (daughter) strand

strands growing in pieces

Okazaki fragments

lagging strand

discontinuous DNA synthesis

leading strand

continuous DNA synthesis

DNA polymerases

need a small primer to extend

RNA primases

must make primer fist

DNA polymerase iii

extends from the primer

to make lagging strand continuous…

DNA pol 1 replaces with DNA

DNA ligase

connects Okazaki fragments

RNA primase and DNA pol iii make

leading strand

helicase

singe stranded binding proteins

start of DNA replication

eukaryotes - multiple origins

prokaryotes- one origin

telomere

repeats of a short sequence at ends of chromosome

consist if many copies of a short sequence

telomerase

enzyme that remakes telomere after DNA replication

has complementary template and polymerase activity

somatic cells

most cells in body

little to no telomerase activity

can only divide a certain number of times

DNA replication (S phase) creates

sister chromatids

prophase

chromosomes condense

centrosomes radiate spindle microtubules and migrate to opposite ends of cell

prometaphase

nuclear envelope breaks down

microtubules (spinde apparatus) attaches to chromosomes at kinetochore

metaphase

chromosomes line up along center of cell

anaphase

sister chromatids separate and move toward opposite poles

telophase

chromosomes arrive at spindle poles

nuclear envelope reforms

chromosomes decondense

cytokines - cell division

separate process from mitosis, but usually begins during telophase

cyclins

non-enzyme proteins expressed at certain point in the cell cycle

cyclin-dependent kinases (CDK’s)

required for cell to move through check points

DNA checkpoints

Spindle assembly checkpoint

DNA damage checkpoint

DNA replication checkpoint

the 3 common cyclin-CDK complexes

G1/S cyclin-CDK complex prepares cell for DNA replication

S cyclin-idk helps initiates DNA synthesis

M cyclin-CDK helps prepare the cell for mitosis

what enzyme unwinds the two parental strands to form the replication fork

helicase

what enzyme is responsible for making the RNA primer

RNA primase

what enzyme extends the daughter strand from the primer

DNA polymerase iii

parental homologos

one member of a chromosome pair. one comes from mother one comes from father

sister chromatids

replicate of a chromosome formed through DNA replication

centromere

regain of a chromosome where microtubules will attach

spindle fibers

microtubules attached to centromeres that will be involved in separating sister chromatids during cell divisions

biotechnology (12)

manipulate this for our benefit

genetic analysis often requires

DNA isolation, make many copies of a gene (part) determine DNA sequence

Polymerase Chain Reaction (PCR)

replicate DNA over and over (amplify DNA)

steps of PCR

denaturation - unzip DNA by raising the temps

annealing - primers attach by complimentary base-pairing

extension - DNA adds dNTPs starting at the primer

repeat

PCR polymerases problem

each denaturation temp is around 94 C that desotryes polymerase

PCR polymerases solution

add more polymerase each cycle (tedious)

use a polymerase from bacteria that live in a very hot environment

thermos aquaticus - lives in hot springs

enzyme is named Taq polymerase

during PCR, which reagent, added by the lab worker, determines what piece of DNA is targeted

primers

gel electrophoresis

separating DNA fragments by size

restriction enzymes

cut DNA at restriction sites

plasmid

DNA molecule that is small, circular, double stranded, distinct from a cells chromosomal DNA, in bacteria cells

sequences that read the same in both directions are

palindromic

recombinant DNA technology

DNA cloning - use of restriction enzymes DNA too be cloned (donor DNA) is combined with vector DNA

genetic modified organism

transgenic organisms (gene added/removed)

powerful models for research

CRISPR

method to change the sequence of any gene in a cell

genome annotation

the process of identifying these sequences

genotype (13)

genetic makeup of a cell or organism

polymorphisms

common genotype mutations

alleles

different forms of any particular gene

homozygous alles

if 2 alleles are the same (dominant or recessive)

heterozygous

if 2 alleles are different

phenotype

observable expressions of a trait

can be physical, behavioral, or biochemical

determined by genotype and environment

harmful genetic differences

coming increase susceptibility to disease

neutral genetic differences

negligible effects

dosent effect survival/ reproduction

beneficial genetic differences

bitter taster/ contester receptor phenotype

ex. lactase persistence

CCR5 is a co receptor for HIV

sickle cell anemia

mutations of the b-globin gene, subunit of hemoglobin

sources of spontaneous mutations

mistakes by DNA polymerases

sources of induced mutations

x-ray, UV lights, chemicals

germ-line cells

egg, sperm and cells giving rise to them

somatic cells

all other cells in the body where mutations occur

what happens when DNA polymerase proofreading fails

it leads to a nucleotide substitution (point mutation)

silent (synonymous) mutation

same amino acid

missense (nonsynonymous) mutation

similar or not