Transcription & Translation xx
codons may be redundant but they are not AMBIGOUS one codon will not specify more than ___ amino acid(s)
1.
FREE RIBOSOMES MAKE PROTEINS FOR ___ AND BOUND RIBOSOMES MAKE PROTEINS FOR ___ SYSTEM ABD PROTEINS EJECTED FROM CELL
1. CYTOSOL 2. ENDOMEMBRANE SYSTEM
in insertions and deletions, there are _______ and ____ to nucleotide pairs in a gene. these mutations are ____ than substitutions what might be altered by these muations creating a ____ mutation
1. additions/losses 2. worse 3. reading frame altered creating a FRAMESHIFT mutation
the 5 cap and polyA tail have 3 imp functions which are
1. export mature MRNA out of nucleus 2. protect MRNA from degradation by hydrolytic enzymes 3. help ribosomes attach to 5 end of MRNA once it reaches cytoplasm
3 kinds of nucleotide pair substitutions in silent mutations, there is ___________ due to genetic redundancy in missense mutations, the _____ is coded in nonsense mutations, an amino acid codon is changed into a _____, creating a nonfunctional protein
1. no effect on amino acid made by codon 2. wrong amino acid 3. stop codon
InitIation of transcription is when transcription factors are added to the ____ and RNA POLYMERASE 2 BINDS TO IT. this is then called the transcription initation complex and is formed by _____ RNA POLYMERASE UNWINDS DNA STRANDS AND TRANSCRIBES a template strand at start protein (RNA SYNTHESIS)
1. promoter 2. TATA
NOT ALL PROTEINS ARE ENZYMES... MANY are made from 2 or more ___ chains have their own gene ex- keratin, insulin
2+ polypeptide chains that have their OWN GENE
In elongation of rna strand, RNA POLYMERASE ADDS TO THE ___ END OF GROWING RNA MOLECULE. many polymerase molecules may transcribe _______________
3 end of RNA A SINGLE GENE TO MAKE LOTS OF A CERTAIN PROTEIN
DNA IS read in the ____ orientation and ____ in a gene are what specify amino acid sequence of a polypeptide.
3 to 5 direction CODONS
in MRNA, the 5 end which is made first receives a ________ made of guanine. the 3 end has enzymes add ________ blocks to make a _____ tail.
5 cap adenine blocks, polyA tail
reading frame is important in translation, must be read in ___ direction
5-3
in transcription, a __ sets the order of nucleotide bases in the rna that is about to be synthesized. for every ___ , the _________ is transcribed.
A GENE SETS ORDER FOR EVERY GENE, THE TEMPLATE STRAND IS TRANSCRIBED.
what dictates synthesis of proteins/ other rna molecules involved in proteins synthesis
DNA
nucleic acid RNA is the bridge between _______ and ____________
DNA AND PROTEIN SYNTHESIS
what enzyme matches tRNA and AMINO ACIDS and catalyses the covalent bond of amino acid to tRNA from ATP hydrolysis
aminozcyl tRNA synthetases
IN PRE-MRNA SPLICING, A _________ REMOVES INTRONS AND JOINS EXONS
SPLICESOME
in translation, the ____ IS READ AS CODONS WHICH WAY IS MRNA READ?
THE MRNA IS READ AS CODONS MRNA IS READ IN 5 TO 3 DIRECTION
____ IS THE SYNTHESIS OF A POLYPEPTIDE CHAIN NEEDING ___ AND __/____
TRANSLATION protein factors energy / GTP
IN TERMINATION OF TRANSCRIPTION IN BACTERIA, POLYMERASE DOES WHAT?
detaches from DNA, releases transcript.
iN TERMINATION OF TRANSCRIPTION IN EUKARYOTES, POLYMERASE CONTINUES TRANSCRIBING UNTIL WHAT?
enzymes cause polymerase and dna to separate
genes can be transcribed/translated ______
from one species to another
what is the process by which dna directs protein synthesis through transcription and translation
gene expression
spontaneous mutations occur during DNA replication, recomposition, and repair what are the physical or chemical agents that cause mutations
mutagens
what affects protein structure and function, a change in the genetic material of a cell or virus
mutations
in eukaryotes, what separates translation and transcription?
nuclear envelope
because prokaryotes lack a __________ , transcription and translation are coupled.
nuclei ribosomes attach mRNA translation starts while transcription is in progress
what are the 2 Diff kinds of SMALL SCALE POINT mutations?
nucleotide pair substituions insertions/ deletions
what is an anticodon
nucleotide triplet on tRNA that base pairs to the codon of the mRNA so the amino acid can detach.
in a nucleotide pair substitution, what happens?
one nucleotide and its partner is replaced with another pair of nucleotides
in sickle cell there is a _____ mutation of a gene that encodes B global polypeptide of hemoglobin
point
what are chemical changes in just one base pair of a gene
point mutations
what is modified after translation?
polypeptide chains completed proteins sent to specific sites in cell
what is formed when lots of ribosomes translate a single MRNA at the same time enabling a cell to make lots of polypeptide copies?
polyribosomes
in transcription, the initial rna transcript that is not TRANSLATED INTO PROTEIN is a __________
primary transcript
the three stages of translation (initiation, elongation, and termination) all require what ?
protein factors
IN TRANSCRIPTION, mRNA carries the genetic message from DNA into ______________________________
protein making part of the cell
___ ARE THE LINK BETWEEN GENOTYPE/PHEOTYPE
proteins
what allows certain tRNAS to bind to more than one codon? flexible base pairing in 3rd nucleotide base in same codons for certain AA
wobble or flexible pairing on the 3rd codon base
what facilitates specific coupling of tRNA anticodons and MRNA codons in protein synthesis?
ribosomal subunits made of proteins and ribosomal rna
in prokaryotes, ____ attach to the MRNA while transcription is in progress?
ribosomes
ribosomes switch between free and bound. bound ribosomes are made by a _____ which EMERGES FROM RIBOSOME OF SRP(a protein rna complex) andtargets proteins to ER
signal peptide
start code AUG does what?
signals protein making machines to TRANSLATE MRNA
the change of just a _____ in the DNA template strand can make an abnormal protein
single nucleotide
in translation , what helps MRNA message translate into protein? each tRNA has a ____ 3' end and a ___ on the other end.
tRNA specific amino acid on 3' end anticodon on other end
_____ is making mRNA from DNA
transcription
in eukaryotes, transcription happens in ___ and translation happens in ___ at ___
transcription- happens in nucleus translation - happens in ribosomes at cytoplasm
__ IS MAKING A PROTEIN SEQUENCE FROM MRNA AT RIBOSOMES
translation.
the flow of info from gene to protein is based on the _____________ which is 3 nucleotides that are made into an amino acid chain
triplet code
IN ELONGATION, amino acids are added to the ___ terminus
C
a gene is a DNA SEQUENCE THAT __________ FOR A SPECIFIC POLYPEPTIDE CHAIN and can be expressed to make a polypeptide or an RNA molecule
CODES
noncoding chunks of nucleic acid in between coding regions are ______ regions that are EXPRESSED by being translated into AMINO ACID sequences are ____
INTRONS EXONS
TRANSCRIPTION IS MAKING ___ ON _____ . TRANSLATION IS TRANSLATING THE NUCLEOTIDE SEQUENCE OF mRNA INTO _____________________
IS MAKING RNA ON DNA AN AMINO ACID SEQUENCE OF A POLYPEPTIDE
the one gene, one _____ hypothesis states how each polypeptide has one gene. what is the exception to this rule when quite a few genes code for the RNA molecule.
ONE POLYPEPTIDE ALTERNATIVE SPLICING
in RNA processing in eukaryotic cells, RNA IS modified after transcription. both ends of the ____ transcript is altered and certain parts of RNA are cut with the rest spliced together. THIS happens to premrna in nucleus before genetic message is sent to cytoplasm
PRIMARY
in termination of translation, a ribosome reaches the stop codon on MRNA. what promotes hydrolysis and causes ribosomal subunits to disassociate
RELEASE FACTOR PROMOTES HYDROLYSIS
what are RNA molecules that act as enzymes ? intron rna is an example that acts as a ribozyme by _______________
RIBOZYMES catalyzing its own excision
3 prop of ribozymes that allow it to act as enzymes
RNA IS SINGLE STRANDED W A CERTAIN 3D STRUCTURE RNA BASES HAVE FUNCTIONAL GROUPS THAT MAY ACT AS CATALYSTS RNA CAN H BOND TO OTHER NUCLEIC ACIDS (RNA/DNA) WHICH ADDS SPECIFICITY TO ITS CATALYTIC ACTIVITY?
In making a primary transcript for a gene, __ TRANSCRIBES INTRONS AND EXONS FROM DNA but MRNA enters cytoplasm as an ABRIDGED VERSION. when introns are cut and exons joined, forming a ____ with a ______________
RNA POLYMERASE 2 MRNA with a continuous coding sequence
in the initiation step, a ____ binds to mRNA and a _____ completes the initiation complex. SOURCE IF ENERGY FOR INITIATION COMPLEX
a small ribosomal subunit a large ribosomal subunit hydrolysis of GTP
large scale mutations are ______________ that affect long segments of DNA small scale mutations are mutations of _____________________ and ________________ which are changes in single nucleotide pair of a gene
chromosomal rearrangements a few nucleotide pairs, point mutations
the nontemplate strand is also called a __ strand.
coding strand
in the elongation step are what 3 processes that are required in order for the ribosome to be ready for the next AMINOACYL TRNA AMINO END OF A POLYPEPTIDE.
codon recogition peptide bond formation translocation