Cell Biol Final Review

Front 1

why is tRNA considered the translator of translation

Back 1

read the nucleotide language and arragents the respective aa tRNA to bind.

Front 2

what is the anticodon? In which direction is it read?

Back 2

complimetnary protion fo the aminoacyl tRNA that is read three to five

Front 3

what two functions does aminoacyl tRNA synthetase perform

Back 3

binds aa to respcetive acyl tRNA
activates the aa so it is ready for a peptide bond

Front 4

at which end of the tRNA does the aa bind

Back 4

five

Front 5

what aminoacyl tRNA is only aatRNA that can bind directly to the p site

Back 5

fmet tRNA
codes for methionine

Front 6

waht are the three nucleotides of DNA that make up the start codon? waht are the three nucleotides of RNA that make up the start codon?

Back 6

DNA ATG
RNA AUG

Front 7

is the RNA the same as the template or complimentary

Back 7

same

Front 8

where are the P and A sites located on the ribosome

Back 8

small subunit
P site is 5' to the A site

Front 9

what enzyme binds the growing peptide in the p site to the amino acid in the A site

Back 9

peptidyl transferase activity

Front 10

the release of peptide and final tNRA is signlaed by what codon

Back 10

stop
then releasing factor comes in

Front 11

wha tis cotranslation import and why does it occur?

Back 11

translation and translocation of the peptide into the lumen of the ER
will either become a vesicle or some type of organelle
important because membrane associated proteins must be associated with soem sort of membrane and in this case its the ER

Front 12

where does cotranslaitonal improt occur

Back 12

at the membrane of the ER

Front 13

do translation and import occur at th e same time?

Back 13

yes

Front 14

what is the signal peptide? why is it important?

Back 14

the first 15 to 20 aa on a prot that is going to be membrane associated
tells teh system that it is going to membrane associated and it will kow to send it to the ER

Front 15

what is the signal recognition particle and what two molecules does it bind?

Back 15

SRP binds nascent peptide and GTP

Front 16

what is the signal peptidase molecule? what part of the nascent peptide does this molecule cleave?

Back 16

cleaves off the first 15 to 20 aa residues of the nascent peptide at the N terminus
a new terminus is then made that is part of the funcitonal protein

Front 17

peptides are always synthesized ___ terminus to ___ terminus

Back 17

A
N

Front 18

what is the stop transfer peptide? what function does it perform?

Back 18

a sequence that is in the interior portion of the peptide that stops translocation into the ER.

Front 19

what happens whne the stop transfer peptide comes along

Back 19

translation sotps in ER but continues in the cytosol

Front 20

what kinds of proteins are made on the rough ER

Back 20

membrane associated proteins... nto necessarily membrane bound

Front 21

how are hormones transported from one organ to another? how does this differ from neurotrans trasnprot from one cell to another?

Back 21

hormones are by definition transproted by the vascular system or circulatory sytem. They can be like autocrine or paracrine. Most are transproted by large blood vessels. Neurotrans are secreted by presynaptic membrane which is very close to the postynaptic membrane.

Front 22

what are some major classifications of hormones? give an example of each

Back 22

aa derivatives like epi and NE
short peptides like ADH
large peptides like inslulin
small molecules like NO

Front 23

what are the four intracellular events that occur after the hormone binds to a cell surface receptor tyrosine kinase? RTK

Back 23

conformational change in the receptor. Then autophosphorylation
recruitment of molecules
gene expression

Front 24

what is the ligan in the hormone receptor system? Does the ligand bind to the receptor covalentyly?

Back 24

the molecules that interacts iwth the receptor
No, interaction is ionic

Front 25

what is a second messenger

Back 25

an intracellular molecule that amplifies the information from the primary signal

Front 26

what ist he primary funcitn of a secon dmessenger

Back 26

to amplify information

Front 27

what are examples of second messengers

Back 27

IP3
DAG
ca
cAMP
cGMP

Front 28

true or false. AC is found floating freely in the cytoplasm

Back 28

false. it is an integral protein but does NOT transverve the plasma membrane it is jsut partially bound

Front 29

what is the molecule that directly activates AC

Back 29

alpha subunit of the g prot

Front 30

what is a g protein? how many subunits do most g proteins ahve? which subunit functiosn as a gtpase enzyme?

Back 30

guanin nucleotide binding proteins
guanine nucleotides are GTP and GDP. when voudn to GTP active the proteins are heterotrimeric prot with alpha beta gamma.

Front 31

what kinds of nucleotide molecules do the g proteins bind

Back 31

guanine nucleotides GDP and gTP

Front 32

when the hormone binds the receptor what molecule replaces GDP on the g protein

Back 32

GTP. GTP displaces GDP.

Front 33

the alpha subunit of the g protein eventually inactivated is the result of what two events?

Back 33

hormone dissociates from teh recpeotr
hormone and the receptor are endocytosed
degredation for the hormone or ligand
inactivation is the alpha subunit turns on and becomes GTPase that will cleave off the phosphate

Front 34

t or f. the alpha subunit dissociates from teh beta gamma dimer when the alpha subunit is bound to GTP

Back 34

true

Front 35

be able to label a diagram that involves H Rc G prot and AC

Back 35

not on the exam

Front 36

cAMP is the product of AC activity and the metabolite of what molecule

Back 36

ATP

Front 37

cAMP binds to what protein kinase? to which subunits of this kinase does cAMP bind

Back 37

Protein kinase A
A is associated with adenosine nucleotide
binds to the regulatory subunit

Front 38

the binding of camp to the subunits mentioned in quesiton 16 causes two events to occur to this kinase molecule. name the events

Back 38

dissociation of the regulatory subunit from the catalytic subunit
activation of the kinase

Front 39

what is a kinase?

Back 39

a general term for enzyems taht transfer gamma from ATP onto the substrate

Front 40

what is the funcito of a kinase

Back 40

to transfer gamma phophate from ATP to substrate

Front 41

what other two molecules must be present for an active kinase to have an effect in the cell?

Back 41

ATP
substrate

Front 42

calcium cannot permeate lipid membranes. waht two mech are avail to calcium to increase the intracell concentration of Ca2+

Back 42

ligand gated channels on PM
ligand gated channels on ER

Front 43

what is a ligand gated channel

Back 43

regulated by a receptor that when bound to its respective ligand open up that channel
in particular the ER IP3 gated channel allows calcium to flow into the cytoplasm

Front 44

what molecule binds to calciumand becomes active as a ca complex

Back 44

calmodulin

Front 45

what is PIP2?

Back 45

a reall huge molecule that has two fa that are anchored into the membrane and one inositol hanign off

Front 46

what second messengersa re produced by the hydrolysis of PIP2

Back 46

DAG and IP3

Front 47

which one reminas mbmrane boudn and which becomes cytosolic

Back 47

DAG is membrane bound
IP3 is cytosolic

Front 48

be able to looks at a PIP2 and decid what part is DAG and what is IP3

Back 48

grr

Front 49

what do DAG and IP3 do after they are separated from their parent molecule PIP2

Back 49

DAG stay membrane and interacts iwth PKC
IP3 interacts with IP3receptor

Front 50

what enzyme hydrolyzes PIP2 to DAG and IP3

Back 50

PLC

Front 51

what is a peptide growth factor? give two examples

Back 51

peptide hormones
EPG
IGF
peptide hormones that induce cell division

Front 52

receptors for GFs are a particular kind of receptor what is it

Back 52

RTKs
receptor tyrosine kinases

Front 53

name two molecule that GF receptors phosphorylate

Back 53

themsels
adapter proteins whch are close proximity and may phsophorylate all those prtoeins near it

Front 54

steroid receptors are found in teh clel rather than on the cell surfac.e what special property do steroids have that allow for cytoplasmic or nuclear steroid receptors?

Back 54

they are lipids
so lipophilic

Front 55

the steroid receptor complex acts as a cis acting element or trans

Back 55

trans acting because it mostly made up of protein tha tis the transcription factor that acts on DNA

a cis factor means the same that DNA seq that the factor acts on

Front 56

the enzymatic of ___ binds the incoming aa to the newly forming peptide during the elongatio step of translations. This activity was ounce thought to be a ___ associated, but is now believed to be ____ associated activity

Back 56

peptidyl transferase
protein
ribosomal

Front 57

the process by which the ER uptakes an incipient polypeptide concurrent with the translation of the peptide is called ____

Back 57

co translational improt

Front 58

polypep destined to be secreted or associated with endosomes or the palsma membrane have a special seq of 15 to 20 aa residues at the N terminus called the

Back 58

a or b

Front 59

aa bind to the ___ end of the tRNA and are linked to the tRNA via a ___ bond

Back 59

3'
ester

Front 60

the ___ particle ____ halts the translation of the mRNA ot a polypep before docking to the ER

Back 60

signal reocgnition
temporarily

Front 61

four membrane associated proteins, the consense sequence ___ is ofund on the incohoate polypep and causes ____ to halt

Back 61

stop transfer seq
translocation

Front 62

metheyl 7 guanosine is found at the ___ end of the processed RNA from a euk organism

Back 62

5'

Front 63

a peptide hormone like VEGF binds ___ to its receptor

Back 63

temporarily

Front 64

the primary funciton of the second messenger is to ___ the external signal fo the hormone

Back 64

amplify

Front 65

the ___ subunit of most heterotrimeric G proteins binds to the guanine nucleotides an dacts as a ___ when it becomes inactivated

Back 65

alpha
GTPase

Front 66

cAMP molecules bind to the regulatory subunits of PKC
true or false

Back 66

false
PKA?

Front 67

the second messenger IP3 and DAG are products of PIP2 hydrolysis. The enzyme that promotes the production fo these two molecules is called ___

Back 67

PLC

Front 68

DAG activates ___. In turn this kinase ___ its own substrates

Back 68

PKC
phosphorylates

Front 69

after a steroid hormone binds to its receptor, the steroid receptor complex tanslocates to the __ where it binds to a ___. Thus, the steroid receptor complex acts as a ____

Back 69

nucleus
DNA seq
trans acitvating factor

Front 70

protein kinases are ubiquitous throughout all cells. The funciton of a protein kinase is to __ its substrate using __ as a source of phosphate molecules

Back 70

phosphoyrlate
ATP

Front 71

the retinoblastoma gene Rb is a nuclear phosphoprotein. Whne phosphorylated it dissociated from the E2F protein and transcription via the E2F protein beings. This indicates that RB protein ___ the activity of E2F when not phosphorylated and is regulated by activity of a

Back 71

inhibits
kinase

Front 72

the p53 protein plays an importatn role in the cell cycle. The p53 gene is considered to be a __ gene

Back 72

conserved

Front 73

the p53 gene codes for p53 nuclear proteins. When the cell si damged htere is an upregulation of p53 concentration due to a decrease in its ___. Increased amounts of p53 cuases the transcription fo the gene p21 a CDK inihibitor. This suggest that p53 acts as a ____

Back 73

degradation
transcription factor

Front 74

in the mammalian cell system, steroid receptors that are not boudn to their ligands are commonly found in ___

Back 74

the cytosol or inthe nuclesu

Front 75

guanin nucleotide protein coupled receptors are associated with heterotrimeric g proteins. GTP displaces bound gDP on the ___ of the G protein. At thsi moent, the affinity for GTP by this subunit is less or greater or same as the affinity for GDP

Back 75

alpha
greater than

Front 76

poly adenlyation is found on the ___ of the processed mRNA. It is the cell's way of ___ the half life of the message

Back 76

3'
increasing

Front 77

the transformation of cells by the onco.... this base pair sub in codon12 codse for the __ amino acid residue

Back 77

12th

Front 78

the production of cAMP is directly regulated by two enzymes ___ and ___. the formed is a ___ protein whereas the latter is a ___ protein

Back 78

PDE
AC
cytosolic
peripheral

Front 79

when EGF bind to its receptor, epidermal growth factor recepter, it chagnes the conformatino fo theEGFR such tha tit interacts with another bound EGFR. IN order for the EGF signal to be transduced into the cell,the EGFR msut interatc with anotehr EGFR in order to transduce the EGF signal. Thus, two EGFRs act as a functiaonl ____ or in other words, a multimeric polypep

Back 79

homodimer