Studied by 0 people
Looks like no one added any tags here yet for you.
cellular respiration
breaking down food/glucose to produce energy/ATP (adenosine triphosphate)
glycolysis
breaking down glucose into pyruvate and occurs in the cytoplasm of all living cells
aerobic respiration
what cells undergo when oxygen is present
anaerobic respiration
what cells undergo when oxygen is not present, but an alternative electron acceptor exists
fermentation
what cells may undergo when oxygen is not present and no alternative electron acceptor exists
mitochondrion matrix
where enzymes of the krebs cycle reside and where pyruvate oxidation happens, DNA and ribosomes
outer membrane
50% protein, 50% lipid by weight, most abundant protein channels porins
intermembrane space (IMS)
composition of ions and small molecules is the same as the cytoplasm
inner membrane
site of ATP generation, 70% protein (no porins),
pyruvate oxidation
breaking down pyruvate by taking a carboxyl group, making CO2 to make acetyl-CoA
krebs cycle (citric acid cycle)
oxidation of acetyl-CoA, produces 2 CO2, 3 NADH, 1 FADH2, and 1 ATP
electron transport chain
series of 4 protein complexes and other molecules which transfer electrons from electron donors to electron acceptors
chemiosmosis
the movement of ions across a semipermeable membrane bound structure, down their electrochemical gradient
oxidative phosphorylation
uses oxygen to create ATP
allosteric regulator
a substance that binds to a protein at a site other than the active site, altering the protein's function
positive regulator
increases activity of the enzyme
negative regulator
decreases activity of the enzyme
feedback inhibition
activity of an enzyme is inhibited by the end product of a biochemical pathway
first committed step
the first step you can stop without interfering with more than one product
transcription
nucleotide sequence being copied to an RNA intermediate
translation
nucleotide sequence being used to build proteins
central dogma
flow of genetic information from DNA to RNA to protein
chromatin
complex of DNA and proteins that forms chromosomes in the nucleus of eukaryotic cells, "beads on a string"
Chargaff's rules
amount of dNTPs differ between organisms, but amount of A=T and C=G
Rosalind Franklin and Maurice Wilkins
got image of DNA with X-ray crystallography
James Watson and Francis Crick
discovered the double helix model of DNA
origin of replication (ori)
a sequence of bases found in prokaryotes that signals the start site of DNA replication
helicase
enzyme that untwists the double helix of DNA at the replication forks
single stranded DNA binding proteins (SSB)
keeps strands apart for replication to occur
topoisomerase (swivel)
cuts and reglues DNA strands to be able to continue moving helicases in replication
DNA strand synthesis
incoming dNTP is hybridized to parental template and phosphodiester bond formed with 3' end of chain
leading strand
the new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5' to 3' direction away from the ori
lagging strand
the strand that is synthesized in fragments working back toward the ori
Okazaki fragments
small fragments of DNA produced on the lagging strand during DNA replication
DNA polymerase
enzyme that joins individual nucleotides to produce a DNA molecule
primase
enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template.
primer
a short stretch of RNA opposite an ss-DNA template
DNA polymerase I
removes RNA primers and replaces them with DNA
DNA ligase
enzyme that forms phosphodiester bonds between DNA fragments together, sealing "nicks"
"X"-dependent "Y"-synthesizing enzyme
"X" = what it's using as a template, "Y" = what it is making
nuclease
enzyme that degrades (hydrolyzes) a phosphodiester linkage
exonuclease
hydrolyzes nucleic acid from the end of a chain
endonuclease
hydrolyzes nucleic acid internally
telomerase
enzyme that catalyzes the lengthening of telomeres
histones
eukaryotic protein molecules that DNA is tightly coiled around in chromatin
nucleosome
bead-like structure in eukaryotic chromatin, composed of a short length of DNA wrapped around a core of histone proteins
chromatosome
nucleosome + H1 histone
euchromatin
less condensed form of eukaryotic chromatin that is available for transcription
heterochromatin
highly condensed form of eukaryotic chromatin
sister chromatids
joined copies of the original chromosome
centromere
region of a chromosome where the two sister chromatids attach
chromosome arms
portions of the chromosome on opposite sides of the centromere
telomeres
ends of chromosomes
RNA polymerase
enzyme that carries out transcription
holoenzyme
E. coli RNA polymerase with 6 subunits
core enzyme
E. coli RNA polymerase subunits without its sigma factor
TATAAT
-10 consensus sequence
TTGACA
-35 consensus sequence
promoter
specific region of a gene where RNA polymerase can bind and begin transcription
terminator
in bacteria, a special sequence of nucleotides in DNA that marks the end of a gene
rho-dependent termination
in prokaryotes, an interaction between RNA polymerase and the rho protein to get it away from DNA
intrinsic termination (rho-independent)
RNA binds with itself, creating a hairpin loop structure
messenger RNA (mRNA)
RNA molecule that carries copies of instructions for the assembly of proteins from DNA to the rest of the cell
ribosomal RNA (rRNA)
type of RNA that combines with proteins to form ribosomes, which are the platform on which protein synthesis occurs
transfer RNA (tRNA)
type of RNA molecule that transfers amino acids to ribosomes during protein synthesis
RNA polymerase I
transcribes rRNA
RNA polymerase II
transcribes mRNA
RNA polymerase III
transcribes tRNA
transcription factors
accessory/regulator proteins that allow RNA polymerase to bind to the promoter sequence
noncoding DNA
in eukaryotes, does not contain genes that encode mRNA/proteins
spacer DNA
noncoding DNA that separates one gene from another
exons
coding segments of eukaryotic genes, "expressing sequences"
introns
noncoding DNA within a gene, "intervening sequences"
small nuclear RNA molecules and proteins (snRNPs)
remove introns and join ends of exons
spliceosome
complex of enzymes that serves to splice out the introns of a pre-mRNA transcript
lariat structure
a ring of intron segments that has been spliced out of a messenger ribonucleic acid molecule by enzymes
thalassemias
defective hemoglobin caused by inaccurate splicing of introns
alternative splicing
not using all exons, creating different mature mRNA, therefore different protein
5' cap
a modified form of guanine nucleotide added onto the 5' end of a pre-mRNA molecule, allows recognition for start of translation
kinase
enzyme that adds phosphate groups
phosphatase
enzyme that removes a phosphate group from a molecule
poly-A tail
a sequence of 50-250 adenine nucleotides added onto the 3' end of an mRNA molecule, providing stability
stop codon
codon that signals to ribosomes to stop translation, UAG, UAA, UGA
aminoacyl tRNA synthetase
an enzyme that joins each amino acid to the appropriate tRNA
ribosomes
site of protein synthesis
70S
prokaryotic ribosome
50S
large subunit of prokaryotic ribosome
30S
small subunit of prokaryotic ribosome
5S rRNA, 23S rRNA, 34 proteins
makeup of the large subunit of prokaryotic ribosomes
16S rRNA and 21 proteins
makeup of the small subunit of prokaryotic ribosomes
80S
eukaryotic ribosome
60S
large subunit of eukaryotic ribosome
40S
small subunit of eukaryotic ribosome
5.8S rRNA, 5S rRNA, 28S rRNA, 49 proteins
makeup of the large subunit of eukaryotic ribosomes
18S rRNA and 33 proteins
makeup of the small subunit of eukaryotic ribosomes
initiation factors
proteins that bring in the large subunit that completes the translation initiation complex
AUG
initiator codon, starts protein synthesis
P (peptidyl) site
binds the tRNA carrying the growing polypeptide chain
A (aminoacyl) site
binds the tRNA carrying the growing polypeptide chain
E (exit) site
binds a tRNA recently stripped of its polypeptide
