Anatomy Exam 1 part 3

michelleburkee2's version from 2016-09-17 01:00

Section 1

Question Answer
nucleolus (3 features)non membranous, cluster of protein, DNA, and RNA, and produces ribosomes
2 features of nuclear membranedouble membrane and has large pores
heredity unit made of DNAgenes
total genetic informationgenome
what makes chromatin?genes and histone protein
ribsosomes are made up of2 subunits (large and small)
function of ribosomessite of protein synthesis
cisternaecurved membrane sacs
the golgi apparatus is involed inprotein secretion
the entry of the golgi apparatusis the cis face (convex entry)
the exit of the golgi apparatusis the trans face (concave exit)
cells function normally as long asthe individual orangelles are functioning normally
apoptosisprogrammed death
central dogma of biologyDNA--->RNA--->protein
transcription"rewriting" DNA into RNA
translationRNA used to assemble protein
where does transcription occur?in the nucleus
where does trasnlation occur?in the cytosol
Protein synthesis begins with transcription (DNA-->mRNA) inside the nucleus
the coding strand is the _____ and the template strand is the _______coding strand is top strand and template strand is the bottom strand
during elongation in trasncriptionavailable nucleotides attatch to exposed DNA nucleotides and start to form an RNA strand
during terminationtranscription occurs until RNA polymerase reaches terminal stop region
at the end of termination, what is formed?Pre mRNA. it must be spliced before leaving nucleus
pre mRNA includesintrons which are noncoding sections of mRNA and exons the coding form of mature mRNA
mature mRNA leavesnucleus through nuclear pore and now is in cytoplasm (cytosol)
when the mRNA reaches the cytosolcytosolic ribosomes or ribosomes on the ER will begin to read the mRNA strand and assemble amino acids to make the protein according to the code that is read

Section 2

Question Answer
what produces ribosomes?nucleolus
genes are arranged onchromosomes
genes combine with ______ to make chromatinhistone proteins
nuclesosomes are seperated by linker DNA
how do ribosomes assist in protein synthesisribosomes attatched to nuclear membranes or ER membranes synthesize proteins for insertion into membrane or exporrt them from cell
free ribosomes sythesizecystolic proteins (staying in cytosol of cell)
the golgi apparatus is composed of3-20 cisternae
protein exits the ER as trasnport vesicle
proteins more through the golgi apparatus as transfer vesicle
proteins exit the golgi apparatus as secretoy vesicle
the full set of chromosomes and thus all inheritable traits of an organismgenome
initiation of transcriptionhelix of DNA must unwind (via enzymes) unzipping causes the nucleotides of DNA to become unpaired
after DNA unwindsRNA polymerase is able to attatch to DNA strand and move along its length. begins to read at its promoter region
intronsnoncoding section of mRNA
exonscoding regions of mRNA
mRNA strand consists of3 nucleotide bases
codonsa triplet (3 nucleotide bases)
thee are _ codons64
___ codons are for amino acids61
___codons are for stop codons3
area between a start-codon and stop codonopen reading frame
most common start codonAUG

Section 3

Question Answer
what is chromatingorm of genetic material in a cell that is NOT in dividing phase
assist in coilinghistones
ribosomes attatched to the nuclear membrane or ER membranes synthesize proteins thatget inserted into the membrane or exported from the cell
free ribosomes synthesize proteins thatare cystolic and stay in the cytosol of the cell
where does RNA polymerase begin to read during transcription?promoter region
enzymes will splice introns are removed and exons remain and are joined
additional posttranslational changes besides splicingcapping one end and forming a poly-A tail on the other
ribosomes produce mRNA and tRNA
3 different sites for tRNA in ribosomeamino acid, peptide and exit
mRNA has codons that pair withtRNA's anticodons

Section 4

Question Answer
is chromatin in dividing phase?no
proteins are made in the _______ then move into the ________ then the ______made in ribosomes, move to Endoplasmic reticulumn and then to the golgi apparatus
cis faceentry of golgi apparatus
trans faceexit of golgi apparatus
a chromosome is made up of _______ which is made up of ____made up of genes which is made up of DNA
what is the first step of transcription?DNA unwinds
what is the second step of trasncription?RNA polymerase is able to attatch to DNA strand and move along its length
each ______ will bring a specific amino acid to the ribosome according to its anticodontRNA
initiation of translationribosome reads the mRNA molecule begining with start codon. tRNA will bring amino acid to the site binding its anticodon to the codon on mRNA
elongation of translationpolypeptides increase in length one amino acid at a time. initiator tRNa fits into peptide site of ribosome. anticodon of another tRNA pairs with second mRNA codon at the Amino site of the ribosome. dehydration synthesis produces peptide bond between amino acids
how many peptide bonds are formed per second during elongation?15
termination of translationtranslation stops when ribosome reaches a stop codon at the Amino site
protein synthesisgene expression
control of gene expressionoccurs in relation to transcription and translation
5 steps of control of gene expressionpretranscriptional, transcriptional, posttranscriptional, translational, and postranslation
what must happen before the polypeptide is functional after translation?polypeptides must fold into distinct three dimensional formations
what helps fold polypeptides?chaperone proteins
chaperone proteins functionbind to and stabilize unfolded or partially folded polypeptides leading to the final correctly folded state
in the abscense of chaperonesunfolded or partially folded polypeptide chains can be unstable within the cell (folding incorreclty or aggregating into insoluable complexes)
5 additional posttranslational modifications besides folding attatch to other biochemical functional groups, attatch to various lipids or carbs, make structural changes to it, enzymes might remove certain amino acids from some location in polypeptide, or activate or inactivate an enzyme
most polypeptides start with the AA methonine because the "start" codon (AUG) on mRNA also codes for this amino acid. it is usally taken off during post-translational modificaiton
one finished with posttranslational control, the proteins will eitherremain in cell or be exported to the cell membrane or out of the cell
the proteins that remain in the cell are made byfree ribosomes in the cytoplasm
the proteins that will be exported are made byER membrane bound ribosomes

Section 5

Question Answer
what brings an amino acid to the ribosome based on the anticodon of mRNA?tRNA
the P site of ribosomeholds the tRNA with growing polypeptide of amino acids attatched
the E site of ribosomeholds a tRNA that will exit
the A site of ribosomeholds an aminoacyl tRNA
aminoacyl tRNA is an enzyme that attaches the appropriate amino acid onto its tRNA.
AA methonine is usally ________posttranlationtaken off
3 functions of golgi apparatus in export of proteinsmay modify proteins, may be sorted and then packaged in vesicles, and vesicle moves toward cell membrane and then fuses with it releasing protein molecules as a secrtion into the extra cellular fluid
extracellular fluidfluid outside of cells
substrateswhat enzymes act upon. becomes a product after being catalyzed by an enzyme
enzymes often end in-ase. usually shares a similar name to its substrate.
each enzyme is specific to onesubstrate
what happens to the enzyme after finishing catalytic reaction with substrate?it is still in tact
what type of structure does an enzyme havequarterary structure
function of enzymethey are active catalysts that speed up chemical reactions
how are enzymes fromed?via protein synthesis
where are enzymes found?some stay in the cell, some become imbedded in the cell membrane, and some are secreted from the cell
2 parts of an enzymeactive site and allosteric site

Section 6

Question Answer
synthesizes lipids and also performs other functionssmooth ER
shuttles lipids to various locations such as golgi apparatustransport vesicle
brings substances into the cell that are digested when the vesicle fuses with a lysosomeincoming vesicle
fuses with the plasma membrane as secretion occurssecretory vesicle
modifies lipids and proteins from ER and sorts them and packages them into vesiclesgolgi apparatus
folds and processes proteins and packages them into vesicles. vesicles commonly go to the golgi apparatusrough ER
amino acid is coded from the correspondingmRNA
primary structure of proteinlinear sequence of amino acids joined by peptide bonds
secondary structure of proteinsstructural pattern within a protein. result from hydrogen bonds formed between amino acids
tertiary structure of proteinfinal 3-D shape of a protein which contains repeating secondary structures
quaterary structure of proteinmolecules composed of 2 or more seperate proteins
protein conformationthree dimensional shape of the protein
beta sheet structures tend to beflexible
alpha helix structures tend to beelastic
what two structures give protein a 3-D shape?tertiary and quarternary structures
globular formtends to be more action orientated. fold into compact shape (i.e. antibodies, enzymes, hemoglobin)
fibrous formtends to form structures. are extended linear molecules (i.e. tendons and other connective tissues)
how do enzymes speed up chemical reactions?by lowering the activation energy of cellular reactions
can chemical reactions occur without enzymes?yes but they will take much much longer
active site of enzymethis is where the enzyme's substrate fits; connection causes "induced fit where active site changes around substrate. yields an enzyme-substrate complex
allosteric site of enzymesite for regulatory binding (substrate does not bind here); induces change in conformation of active site

Section 7

Question Answer
what kind of bonds are in primary structure of proteins?peptide bonds
what kind of bonds are in secondary structure of proteins?hydrogen bonds
the conformation (shape) of enzymes allows them to have specific interactions with substrates (lock and key fit)
becomes a product after being catalyzed by an enzymesubstrate
can an enzyme bind with more than one type of substrate?no. they are specific to each type of substrate.
proteins with shape acheived via quarterary structure that speed up chemical reactionsenzymes
induced fitactive site of enzyme changes around substrate
inhibitionsubstrate cannot fit active site
activation substrate fits active site
5 steps of enzymatic reactions1.)substrate and enzyme form enzyme-substrate complex 2.)enzyme undergoes change in conformation to tighten its fit around substrate 3.) induced fit lowers the activation energy (reaction takes place) 4.)substrate has now become a product and is realeased from enzyme 5.) enzyme can act again on new substrate
two types of reactions caused by enzymesdecomposition or synthesis
factors that alter enzymes reaction ratesconcentration levels of enzymes and substrates, temperature, and pH

Section 8

Question Answer
how do concentration levels of enzymes and substrates effect reaction ratesas concentrations go up, reaction rate accelerates. once all enzyme molecules are active reaction rate plateaus
how does temp effect reaction ratesenzymes work best at optimal temp. if temp is below optimal then reaction rates slow. if temp is too high then enzyme can denature
how does pH effect reaction rateswork best at optimal pH (between 6 and 8). when pH deviates from range the enzyme loses its shape and can die
inhibitorssubstances that can bind to an enzyme and "turn it off" temporarily
competitive inhibitorsshape similar to enzyme, bind to enzyme's active site so that it cannot bind and cause a reaction
noncompetitive inhibitorsshaped differently than enzyme, does not bind to active site but binds to allosteric site of enyme. inhibitor binding to allosteric site triggers a change in conformation in the enzyme (and thus active site)
metabolic pathwaysformed via a series of enzymes ina particular sequence. each enzyme catalyzes in its specific substrate and the product is then released and is then the substrate for the next enzyme in the pathway. at the end of the pathway the product is formed
metabolism is an example of ametobolic pathway
what action is very important to metabolic pathways?adding and removing phosphates
phosphorylationadding a phosphate group
dephosphorylationremoval of a phosphate group
how are metabolic pathways regulatednegative feedback. if an amount of an end product gets too high then some can enter allosteric site and inhibit the pathway (then the amount of end product decreases). when it gets too low again there are fewer products to inhibit the pathways and the pathways become active once again to increase amount of product