Biology Chapter 14 - Gene Expression

gene expression

process by which dna directs messenger RNA (mRNA) synthesis

DNA → mRNA

transcription

mRNA → protein

translation

mRNA directs

protein synthesis

DNA structure

double stranded

DNA’s unique components of nucleotides

deoxyribose sugar and thymine base

DNA is found in

nucleus of eukaryotes

DNA ______ hereditary information

stores and transmits

DNA stores and transmits ______

hereditary information

mRNA structure

single stranded

mRNA unique components

uracil base and ribose sugar

mRNA is made in _____ and moves to ______

nucleus, cytoplasm

mRNA carries…

instructions for synthesizing proteins

transcription

process where genetic information contained in DNA is rewritten as mRNA

template strand

one strand of gene directs synthesis of mRNA

complementary base pairing guides

synthesis

mRNA is ______ to template strand of dna

antiparallel

promoter

dna sequence at which complex of proteins binds and begins transcription of gene 

transcription factors

group of proteins that recruit RNA polymerase to promoter 

RNA polymerase

separates two strands of dna

RNA polymerase moves towards the ____ end of template strand

5’

RNA polymerase catalyzes RNA synthesis in the _ to __ direction

5’ to 3’

RNA polymerase joins together RNA nucleotides that are _____ to the DNA template strand

complementary 

RNA polymerase joins together _____

RNA nucleotides 

eukaryotic promoter → _____ → transcription initiation complex forms 

several transcription factors bind to DNA

______ → several transcription factors bind to DNA

eukaryotic promoter 

several transcription factors bind to DNA → ____

transcription initiation complex forms 

nonsense mutation usually results in

a non-functional protein

template strand of dna directs assembly of _____ molecules

rna

base pairing difference dna and rna

rna has uracil instead of thymine

uracil and thymine pair with

adenine

RNA nucleotides are added to the ___ end of growing mRNA molecule

3’

the strand besides the template strand is the…

coding strand

the coding strand is equivalent to the…

rna product

newly synthesized mRNA strand separates from

template dna

rna polymerase moves towards the ___ of template strand

5’

dna double helix reforms behind _____

rna polymerase

bacteria has ______ nucleus

no membrane bound

in bacteria, transcription and translation occur….

simultaneously

eukaryotes have a _____ nucleus

membrane bound

transcription in eukaryotes

occurs in the nucleus

pre-mRNA

produced in transcription

mRNA undergoes

translation

translation occurs in the…

cytoplasm

result of translation

ribosome and polypeptide

rna processing location and cell type

occurs in eukaryotic cells; takes place in nucleus

rna processing produces

mature rna

mature rna are ready for

translation

rna processing causes ends of pre-mRNA to be altered, adding

5’ cap, 3’ poly-A tail

ends of pre-rna can….

facilitate export from nucleus, protect mRNA from degradation, and recruit translation machinery

splicing

introns are removed

after splicing, ____ are together

exons

alternative rna splicing

allows one gene to encode more than one protein

codons

set of 3 nucleotides of mRNA

mRNA is read as

codons

transfer rna

translates a mRNA codon into a specific amino acid

anticodon 

set of 3 tRNA nucleotides

anticodon pairs with

complementary mRNA codon

each tRNA carries _____ based on its anticodon sequence 

a specific amino acid

amino acids are covalently linked together to produce

a specific protein 

amino acids are synthesized in the ______ direction

N to C

ribosome consists of…

large and small subunits

ribosome is made of….

protein and ribosomal RNA components

ribosomes assemble on…

mRNA

ribosome sites on mRNA

A, P, E

ribosomes

catalyze protein synthesis

ribosomes couple

tRNA anticodons and mRNA codons

ribosomes translate codons into _____

amino acids

translation begins at ______

start codon

A site

holds tRNA carrying next amino acid to growing protein chain

P site

holds tRNA carrying growing polypeptide

E site

where tRNA exits ribosome after transferring polypeptide chain to next tRNA

incoming tRNA base pairs with mRNA in A site →

peptide bond forms between new amino acid in A site and growing polypeptide chain on tRNA in P site

new amino acids added to

carboxyl (C) terminal end

polypeptide chain is transferred to tRNA in

A site 

mRNA slides through ribosome from _____ end

5’ to 3’ 

tRNA A site → 

P site 

tRNA P site →

E site

tRNA E site →

releases

tRNA can be recharged with

specific amino acid