Week 1 Exam Flashcards
these bonds exist between the nucleotides across the DNA strands
hydrogen bonds
these bonds exist between the nucleotides along the sugar-phosphate backbone
covalent bonds
these consist of a nitrogenous base, five-carbon sugar, and phosphate groups
are subunits of nucleic acids
nucelotides
a strong chemical bond with a sharing of electron pairs with a balance of attractive and repulsive forces
covalent bonds
this group is attached to the sugars 5’ carbon
phosphate
this group is attached to the sugars 3’ carbon
hydroxyl
this base attaches to the 1’ carbon
nitrogenous base
nucleotide’s are joined by this bond by it attaching to the 3’ carbon of the next nucleotide to form a polynucleotide
phosphodiester bond
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rate at which observable changes occur in DNA sequences
mutation rate
transmit genetic info from parent offspring (contain heritable info so a mutation in DNA here will affect offspring)
germ cells
form the body ( mutations in DNA of these cells only affect the body not the offspring)
somatic cells
mechanism that cells use to make a complementary sequence of one DNA strand from another
DNA templating
one parent (template) strand and one new strand in each daughter cell
semi conservative replication
keeps DNA double strand from becoming tangled as it unwinds
topoisomerase
this enzyme breaks hydrogen bonds in DNA replication
helicase
continuously synthesized by DNA polymerase
leading strand
synthesized discontinuously in fragments, called okazaki fragments and then ligated together by a different DNA polymerase
Lagging Strand
makes short RNA pieces or primers (10 nucleotides long) on the lagging strand
DNA primase
Steps in making the lagging stand:
- RNA primer binds
- DNA pol adds nucleotides from RNA primer (5’ to 3’)
- DNA pol finishes okazaki fragment
- old RNA primer is degraded and replaced with DNA
- DNA ligase joins new okazaki fragment to the growing strand
push DNA polymerase over the parent strand, allowing correct position of molecules for synthesis
sliding clamp proteins
where DNA duplication begins… there are many of these along eukaryotic chromosomes
replication origin
allows one copy of each duplicate to be pulled into each daughter cell.
centromere
this protein is formed at the centromere and attaches both chromosomes to the mitotic spindle
kinetochore
these repeated sequences form the ends of a chromosome and protect the chromosome from being eaten by DNA repair genes
telomeres/telomerase
the ability of a chromosome to fold and unfold into a densely or loosely packed chromatin makes it a; meaning that it has a physical structure that allows it to change shape
fractal globule (solenoid model)
large proteins that act like combs that DNA can twist around.
condesins
aid in understanding chromatin organization
polytene chromosomes
inherited not within DNA but in addition to it
epigenetic inheritence
highly condensed chromatin that contains very few genes or silenced genes; transcriptionally inactive
heterochromatin
less condensed chromatin that can be packaged into heterochromatin
euchromatin
serve to separate the heterochromatin from the euchromatin at the nuclear pore.
barrier proteins
large blocks of human genome contains the exact same genes in the exact same order as in other mammals
conserved synteny
entire genetic makeup of an organism
genome
Universal Features of All Cells
DNA
- cells replicate through templated polymerization
- use RNA as intermediate via transcription
- use proteins as enzyme catalysts and these catalytic reactions form new DNA
- use tRNA to translate RNA into protein
proteins are encoded by specific genes
- free energy is required of many cell processes (ATP)
- have plasma membranes
- can exist with about 300 genes
a double layer of membrane that surrounds the nucleus and separates the nuclear DNA from the cytoplasm; preforated by nuclear pores
nuclear envelope
this is synthesized on a template that is a preexisting DNA strand with hydrogen bonds formed between the bases
DNA
copying (or templated polymerization) of a single strand of DNA to form a second strand of DNA is called
replication
the idea of DNA is used to make something useful for the organism. so DNA must be expressed as a protein.
central dogma of life
replicates and repairs mitochondrial DNA
Pol γ (gamma)
forms complex with DNA pol subunits to act as a primase (synthesizing RNA primer) then elongates that primer for ~20 nucleotides; starts the process
Pol α (alpha)
primase
exonuclease function involved in lagging strand synthesis; takes over from DNA poly (a)
Pol δ (delta)
exonuclease function synthesizes the leading strand
Pol ε (epsilon)
DNA repair (base excision & gap filling)
Pol β (beta)
non-homologous; end joining repair
Pol λ and μ (lambda and mu)
translesion synthesis; not really good and will replicate through damaged DNA but useful
Pol η, ι, κ (eta, iota, kappa)
small vesicles where hydrogen peroxides are used to inactivate toxic molecules
peroxisomes
take up oxygen and harness energy from the oxidation of food molecules to produce most of the ATP that powers the cells activities
mitochondria
translate RNAs to proteins and it is also where most of the cells metabolic processes take place
ribosomes
segment of a DNA sequence corresponding either to a single protein or a single catalytic, regulatory or structural RNA molecule
Gene
any protein that influences the regions of a DNA molecule that are transcribed by RNA polymerase during the process of transcription
regulatory proteins
no distinct DNA compartment (DNA floats free, have cell walls outside of the plasma membrane, no mitochondria or very few
prokaryotic cells
larger size, more elaborate structure, bigger genomes, DNA in nucleus, complex cytoskeleton, ability to phagocytose things
eukaryotic cells
the way in which DNA information is copied throughout the living world
templated polymerization
Lysosomal storage diseases
gaucher disease, tay-sachs, metachromatic leukodystrophy, hurler syndromes
deficiency of a specific lysozyme located within the lysosomes of the cells. absence of specific lysozyme leads to lack of degradation of certain compounds (glycosphingolipids) and their eventual accumulation in cells
lysosomal storage disease
formed at the G1 phase of the cell cycle. allows for origin of replication to be used. at the beginning of s phase, CDKs phosphorylate replication proteins, causing disassembly of this and initiation of DNA replication
pre-replicative complex
the number of complete homologous sets of chromosomes in a genome
ploidy
different number of chromosomes; a loss or gain of a chromosome, either a sex chromosome or an autosome
Aneuploidy
breakage or loss of a portion of a chromosome that leads to the loss of specific genes in that deleted region
deletions
breakage of two chromosomes with transfer of one broken segment to another chromosome
translocations
breaking of a chromosome at centromere, with one arm of a chromosome being duplicated resulting in a chromosome with two p’s or two q’s
isochrome formations
breakage of two chromosomes with transfer of one broken segment to another chromosome
translocations
disease caused by chromosomal translocation
chronic myelogenous leukemia t(9;22)
