Studied by 14 people
what converts Acetyl-CoA to Malonyl-CoA
Acetyl-CoA carboxylase
what does lipoprotein lipase do
breaks down the triglycerols in the lipoproteins to smaller fatty acids and monoglycerides
what do alpha cells do
secrete glucagon
what do beta cells do
secrete insulin
what do delta cells do
secrete somatostatin
what does somatostatin do
inhibit insulin and glucagon secretion
how does glucose enter beta cells
through GLUT2
what triggers exocytosis
high concentration of Calcium
what is type 1 diabetes
insufficient production of insulin cells
what are characteristics of type 1 diabetes
due to autoimmune destruction of beta cella develops early in life
what is type 2 diabetes
insulin resistance
what are characteristics of type 2 diabetes
develops in late adulthood associated with obesity
what are the symptoms of both types of diabetes
blood sugar becomes elevated body tries to dilute the glucose --> excessive urination and thirst
what is a symptom of type 1 diabetes
fat breakdown is accelerated --> leads to high production of ketone bodies some of the ketones are ketoacids, raise blood [H+] leads to ketoacidosis
what is a high fasting blood glucose level
126 or higher
what is a low fasting blood glucose level
50 in men or 40
what are the long- term effects of elevated blood sugar
increased risk of CV disease, renal failure, and damage to small blood vessels and nerves
what do adipose tissues release
peptide hormones called adipokines
what do adipokines do
carry information about fuel stores to the brain includes leptin and adiponectin
what is leptin
an appetite suppressant and stimulates production of anorexigenic hormones
what NT does leptin inhibit
neuropeptide Y
what NT does leptin activate
alpha-MSH
what is neuropeptide Y
an orexigenic sends signal to eat levels rise in starvation inhibited by leptin and insulin
what is alpha-MSH
an anorexigenic sends signal to stop eating
JAK-STAT mechanism
leptin binds to leptin receptor monomer activates the dimerization of the the leptin receptor travels into the nucleus and induce transcription
what percent of diabetes cases are type 2
90%
what are symptoms of insulin resistance
high triglycerides low HDL high blood pressure elevated blood glucose
what are the nucleotide functions
energy for metabolism (ATP) enzyme cofactors (NAD+) signal transduction (cAMP)
what are the nucleic acid functions
storage of genetic info (DNA) transmission of genetic info (mRNA) processing of genetic information (ribozymes- ribo nucleic acid enzymes) protein synthesis (tRNA and rRNA)
what is a nucleotide
nitrogenous base pentose phosphate
what is a nucleoside
nitrogenous base pentose
what is a nucleobase
nitrogenous base
what are nucleobases
derivatives of pyrimidine or purine
at what nm do nucleobases absorb
250-270 nm
what are the pyrimidines
C, T, U
what are the purines
A and G
how are nucleotides in the pentose ring attached to the nucleobase
N-glycosidic bond
why is the N-glycosidic bond formed
to position N1 in pyrimidines to position N9 in purines
what modification is common in eukaryotes but also found in bacteria
5-Methylcytosine
what modification is common in bacteria only
N6-methyladenosine
what are epigenetic markers
way to mark own DNA so that cells can degrade foreign DNA (prokaryotes) way to mark which genes should be active (eukaryotes)
how many H-bonds to A-T linkages have
2
how many H-bonds to G-C linkages have
3
what does monocitronic mean
one promoter controls expression of one gene
what does polycistronic mean
one promoter controls expression of multiple genes
are eukaryotes monocistronic or polycistronic
monocistronic
are prokaryotes monocistronic or polycistronic
polycistronic
what do palindromic sequences of DNA form
hairpins and cruciforms
how is denaturation of DNA induced
high temperature or change in pH
how is DNA denaturation reversed
annealing
what does a southern blot do
detect DNA from toxins
what does a northern blot do
detect RNA
what does a western blot do
use antibody to detect protein
what are the spontaneous DNA mutations
deamination- very slow reaction depurination- N-glycosidic bond is hydrilyzed
what are the chemical mutations
oxidative damage- hydroxylation of guanine, mitochondrial DNA is most succeptible chemical alkylation- methylation of guanine
what are the radiation- induced mutations
UV light- induces dimerization of pyrimidines ionizing radiation- causes ring opening and strand breaking
what are the RNA viruses
COVID and HIV
what do bacteria contain
extra-chromosomal, double-stranded circular plasmids plasmid exchange is one way bacteria acquire antibiotic resistance
how many chromosomes do humans have
46 chromosomes
what percent of our DNA encodes for proteins
1.5%
what are viral genomic DNA associated with
capsid proteins
what are exons
expressed sequences of DNA
what are introns
regions of genes that are transcribed but not translated
what are transposons
sequences of DNA that can move around account for ~50% of the human genome
what are simple sequence repeats
short (10bp or less) sequences repeated millions of times
what is the telomere repeat sequence in humans
TTAGGG
how are telomeres associated with cellular aging
telomeres are shortened after each round of replication human cells divide about 52 times before losing the ability to divide again
what is chromiatin
fibers of protein and DNA and small amount of RNA
what are histones
small proteins with lots of basic (Lys, Arg) residues
how are histones modified
methylation, acetylation, ADP-ribosylation, phosphorylation, glycosylation, sumoylation, ubiquination
how much DNA is wrapped around a histone
beads are ~146 bp of DNA wrapped around 8 histones
what are the higher order structures of nucleosomes
solenoid model and zigzap model
which way does DNA synthesis occur
addition of new nucleotides to the 3' end
how are Okazaki fragments spliced together
by DNA ligase
what are exonucleases
cleave bonds that remove nucleotides from the ends of DNA
what are endonucleases
cleave bonds within a DNA sequence
what is a primer
short strand complementary to the template contains a 3-OH' to begin the first DNA polymerase-catalyzed reaction
what is processivity
the number of nucleotides added before dissociation
what does DNA polymerase 1 do
is abundant but is not ideal for replication, primary function is to clean up
what does DNA polymerase 3 do
is the principle replication polymerase
what do DNA polymerases 2, 4, and 5 do
they are involved in DNA repair
what does DNA polymerase 1 also do
moves ahead of the enzyme, hydrolyzes things in its path does nick translation this activity is in the Klenow fragment
how many subunits doe DNA polymerase 3 have
10
what is a replisome
the set of enzymes and proteins required for DNA replication in E. coli
what is included in a replisome
helicases, topoisomerases, DNA-binding proteins, primases, DNA ligases
what is oriC
initiation of replication in E. coli contains A-T rich DNA unwinding elements
what makes the RNA primer
primase
what adds nucleotides to the leading strand
DNA pol 3
does the same DNA pol 3
yes, the DNA of the lagging strand loops around
what brings the okazaki fragments together
DNA ligase
how does replication get terminated
replication forks meet at a region with 20bp sequences: Ter
what is Ter
a binding site for the protein Tus
how quickly does eukaryotic replication occur
slowly, ~50 nucleotides/ sec 20x slower than E. coli
how many DNA polymerases are used in Eukaryotic replication
3
what does DNA polymerase alpha do
probably used to make primers for Okasaki fragments
what does DNA polymerase delta do
used in leading and Okasaki synthesis
what does DNA polymerase epsilon do
used in DNA repair
Note
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