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NUCLEIC ACIDS AND
PROTEIN SYNTHESIS
QUESTION 1
DNA
QUESTION 2
To store and transmit the genetic
information that tells cells which
proteins to make and when to make
them
QUESTION 3
They form the structural units of
cells and help control chemical
processes within cells.
Question 4
The nucleotide.
They are
arranged in two
long
complementary
chains.
Question 5
A nitrogencontaining base,
a sugar molecule
called
deoxyribose, and
a phosphate
group.
Question 6
Adenine, abbreviated A
Guanine, abbreviated G
Cytosine, abbreviated C
Thymine, abbreviated T
Purines: Adenine and Guanine.
Have two carbon rings
Pyrimidines: Cytosine and Thymine.
Have a single carbon ring.
Question 8
James Watson and Francis Crick
in 1953.
Question 9
The alternating deoxyribose sugar
and phosphate molecules which
are linked together by covalent
bonds.
Two Views of the DNA
backbone
Sugars
Phosphates
The
backbone is
shown in
yellow in
this
diagram.
Notice that
there are
two
backbones,
one for each
of the
strands of
nucleotides
Question 10
They are covalently bonded to the
deoxyribose sugar and then to the
complementary nitrogen base in
the other strand by hydrogen
bonds.
Backbone
Hydrogen
bonds
Covalent
bonds
Question 11
Guanine from one nucleotide
strand will always pair with
cytosine from the other strand
using three hydrogen bonds and
adenine from one strand will pair
with thymine from the other using
two hydrogen bonds.
Backbone
Two
Three
Question 12
The process of copying DNA in a
cell.
Question 13
The two nucleotide chains
separate by unwinding, and each
chain serves as a template for a
new nucleotide chain.
Red color is
the new
strand. Blue
color is the
original
strand.
Question 14
The point
at which
the two
nucleotide
chains
separate
Replication
Fork
Question 15
They separate the two
complementary chains of
nucleotides in the DNA molecule
by moving along the molecule and
breaking the hydrogen bonds
between the complementary bases.
DNA Helicase
Question 16
Bind to a separated chain of
nucleotides, move along the
separated chain and assemble a
new chain using free nucleotides
in the nucleus and the separated
chain as a template.
DNA Helicase
Polymerase
Polymerase
Question 17
The complementary nature of the
two chains of nucleotides that
make up the DNA molecule. If the
original chain of nucleotides has a
nitrogen base sequence of
CATCAA the other assembled
beside it would be GTAGTT.
Red color is the
new strand,blue
color the
original strand.
The red box is Polymerase
showing the
complementary
bases
mentioned in
the last slide.
DNA Helicase
Polymerase
Question 18
It proceeds in opposite directions
on each original strand.
Replication begins simultaneously
at many points along one original
strand and at just one point on the
other original strand.
DNA Helicase
Polymerase
Polymerase
Direction
of
Replication
Polymerase
Polymerase
Polymerase
Question 19
Two new exact copies of the
original DNA molecule. Each
molecule has one original strand
of nucleotides and a copied
complementary strand.
Original
DNA
Original
DNA
strands
opened up
Two new molecules of
DNA each with one
old and one new strand
Practice making a copy of DNA
Question 20
Replication is very accurate, only
about one error in every 10,000
paired nucleotides.
Question 21
A mutation
Question
22
Enzymes
that
proofread
DNA and
repair
errors
Question 23
A variety of agents, including
chemicals, ultraviolet radiation
and other forms of radiation.
Question 24
The transfer of
genetic
information
from the DNA
in the nucleus
to the site of
protein
synthesis on
the ribosomes.
Question 25
The nucleotide.
The sugar in Question 26
RNA is
ribose in
DNA it’s
deoxyribose.
RNA has the
nitrogen base
Uracil (U)
instead of
Thymine as
in DNA
Question 27
Messenger RNA
(mRNA) - carries
genetic
information from
DNA in the
nucleus to the
ribosome.
Ribosomal
RNA
(rRNA),
combines
with
proteins to
make up
the two
subunits of
a ribosome
Question 27
(continued)
Transfer
RNA (tRNA)
-each binds
to a
particular
amino acid
and brings it
to the
ribosome
The process
by which
genetic
information
is copied
from DNA
to mRNA
Question 28
Question 29
RNA
polymerase.
Makes RNA
copies of
specific
sequences
of DNA
A specific
region of
Question 30
DNA that
marks the
beginning
of that part
of the DNA
The DNA unwinds and the RNA polymerase binds
chain that at a particular site on the DNA. The initial binding
site is called the "promoter region".
will be
transcribed.
Question 31
That portion of the DNA molecule
(only one of the two nucleotide
strands) that is copied by RNA
polymerase.
Template strand
QuickTime™ and a
GIF decompressor
are needed to see this picture.
DNA
Question 32
The nitrogen base sequence on the
template chain and complementary
base pairing by RNA polymerase.
Template strand
QuickTime™ and a
GIF decompressor
are needed to see this picture.
DNA
Complementary base
pairing on mRNA
Nitrogen base
sequence on
DNA
Question 33
Uracil
Template strand
QuickTime™ and a
GIF decompressor
are needed to see this picture.
DNA
The termination
signal - a specific
sequence of
nucleotides on the
template that
marks the end of a
gene.
Question 34
Template strand
QuickTime™ and a
GIF decompressor
are needed to see this picture.
DNA
Question 35
The RNA polymerase
Termination signal
Template strand
QuickTime™ and a
GIF decompressor
are needed to see this picture.
DNA
Question 36
Transcripts - different types of
RNA molecules including mRNA,
tRNA, and rRNA. The mRNA
may have further processing occur.
Noncoding regions called introns
are removed and the remaining
coding regions called exons are
spliced together.
Question
37
Amino
Acids.
Twenty
different
kinds.
Question 38
It’s three dimensional structure,
which is determined by its aminoacid sequence.
Levels of
protein
structure
that
determine
the
function
of a
protein.
Question 39
Triplets of nucleotides in mRNA
that determine the sequence of
amino acids in proteins
Genetic Code
Question 40
A sequence of three nucleotides on
a mRNA molecule. It codes for
one specific amino acid. There are
64 codons.
Genetic Code
codons
codons
start
codons
codons
Question 41
The codon that causes a ribosome
to start translating an mRNA
molecule into a protein. It is
always the nitrogen base sequence
AUG. The codons that cause
translation to cease. There are
three.
start
Question 42
That all organisms are related.
Question 43
The process of assembling
proteins from information encoded
in mRNA. It begins when a
mRNA molecule leaves the
nucleus and migrates to a
ribosome.
Question 44
The
ribosome.
Question 45
tRNA
molecules.
Question 46
A sequence of
three nitrogen
bases on the
tRNA molecule
that are
complementary
to a codon on a
mRNA molecule.
It actually pairs
with the codon on
mRNA.
Question 47
The
complementary
base pairing
between codons
on mRNA and
anticodons on
tRNA
codons
anticodon
Question 48
Composed of
rRNA and
proteins. Make
up 2 subunits.
Found free in
the cytosol and
attached to the
endoplasmic
reticulum.
Question 49
Ribosomes found free in the
cytosol produces proteins used
inside the cell. Those attached to
the E.R. produce proteins used in
the cell membrane or outside of
the cell.
Question 50
One site holds a
mRNA transcript
so its codons can
be read by tRNA.
The other two
sites (P and A
sites) hold tRNA
molecules so that
their attached
amino acids can
be bonded to the
growing chain.
mRNA
holding site
Question 51
Methionine.
Only
initially. It
may be
removed
later.
mRNA
binding site
Start codon
Question 52
A stop codon.
View Translation
Question 53
Yes. Many can. They may form a
chain known as a polysome.
transcript
Review of
Protein
Synthesis:
Transcription
and
Translation