DNA/RNA/Protein Synthesis Flashcards
DNA
deoxyribonucleic acid
units of DNA
nucleotide
3 components of a nucleotide
a phosphate group
a 5 carbon sugar called deoxyribose
nitrogen base
which component of a nucleotide goes in the middle
deoxyribose
4 nitrogenous bases
adenin
thymine
guanine
cytosine
what forms the backbone of a polynucleotide
the sugar and the phosphate
who proposed the double helix model for DNA
Watson and crick
what is between the complementary base pairs
weak hydrogen bonds
purines
adenine and guanine
pyrimidines
cytosine and thymine
what differs one DNA molecule from another
the sequence of base pairs
what does DNA coil around
groups of protein molecules called histones
when the DNA is coiled around histones, what is formed
structures called nucleosomes
when nucleosomes and DNA are packed closely together what is formed
chromatin
chromatin contracts to form
chromosomes
chromosomes are made of
DNA and protein
RNA
ribonucleic acid
what is RNA
made up of a single polynucleotide chain
sugar in RNA
ribose
base in RNA
uracil
1 more difference between DNA and RNA
RNA is single stranded
DNA is double stranded
Messenger RNA (mRNA) made where?
made in the nucleus with the same code as DNA (transcription)
Messenger RNA (mRNA) when it leaves nucleus
leaves nucleus and goes into the cytoplasm
Messenger RNA (mRNA) function
carries code to ribosomes for synthesis of protein
Ribosomal RNA (rRNA) 2 functions
holds the structure of ribosomes
holds mRNA in place for translation
Transfer RNA (tRNA) where is it found
in the cytoplasm
Messenger RNA (mRNA) 3 points about function
each molecule carries specific amino acid to mRNA
binds with complementary codon in mRNA
amino acids placed in sequence
DNA replication
makes a copy of itself
when and where does replication take place
in the nucleus of the cell during interphase
3 requirements for DNA replication
free nucleotides of the 4 different types energy in the form of ATP an enzyme (DNA polymerase)
where are the free nucleotides made?
in the cytoplasm
what does each strand of DNA to during DNA replication
acts as a template or pattern for the synthesis pf a new complementary strand
first stage in DNA replication
2 strands of the double helix unwind
DNA replication; once the strands are unwound
the weak hydrogen bonds are broken by an enzyme
DNA replication; once hydrogen bonds broken
DNA strands separate
DNA replication; strands are separated
DNA nucleotides move in from the cytoplasm and link up with their complementary bases on the separated strands
DNA replication; linked up with new base pairs
nucleotides then joined by an enzyme to make 2 new strands
DNA replication; 2 new strands are made
the old and new strands wind to make 2 new double helices
2 results of DNA replication
2 new molecules formed
Identical to each other and to the original DNA
this replication what named what by Watson and crick
semiconservative replication
when does DNA replication happen
during interphase
each chromosome forms
2 identical chromosomes
where are the identical chromosomes held
at the centromere
significance of DNA replication
identical DNA is passes on to daughter nuclei
codon
triplet
sequence of three bases
what does each codon specify
each codon specifies for one amino acid during protein synthesis
gene
a length of DNA with a sequence of codons that codes for the formation of a protein
when is a gene expressed
when this code is taken to a ribosome and used to make a particular protein
genetic code
sequence of codons in a strand of DNA that codes for a protein
start codon
marks the beginning of the sequence ( a stop codon marks the end)
Coding DNA
the genes that codes for protein
90% of human DNA
non-coding, and is called junk DNA
is non-coding DNA part of the genetic code
no
non-coding DNA
consists of long sequences of bases that do not code for amino acids
where is non-coding DNA found?
between genes and within genes
within genes: coding segment of DNA
exon
within genes: non-coding segment of DNA
intron
what controls cell metabolism
enzymes that are protein in nature
where are proteins made in the cell
in ribosomes
2 things that DNA controls
protein synthesis
and therefore enzyme formation and cell metabolism
protein synthesis requires
mRNA
tRNA
rRna
enzymes/amino acids/ATP
stage one of protein synthesis name
transcription
what occurs during transcription
mRNA is made using a single DNA strand as a template
first step in transcription
DNA strands in the nucleus unwind and separate, controlled by an enzyme
transcription: second step (DNA is unwound)
RNA nucleotides bond with their complementary bases in one of the DNA strands
uracil bonds to
adenine
cytosine bonds to
guanine
transcription: third stage
RNA polymerase joins that nucleotides together to form mRNA
transcription: last step
mRNA leaves the nucleus and carries the codons to the ribosomes
3 types of codons in mRNA
start codon
codon for adding an amino acid
stop codon
stage 2 of protein synthesis name
translation
what occurs during translation
the code in the mRNA is used to make a protein
ribosomes are made of
RNA and protein
translation: first step
rRNA binds mRNA to the ribosomes
where are free-floating tRNA molecules found
in the cytoplasm
describe tRNA
3 bases at one end (anticodon) and specific amino acid at the other end
translation: second step
tRNA molecules carry amino acids to mRNA on the ribosomes
translation: third step
tRNA binds with complementary codons in mRNA
translation: after tRNA has bound with mRNA
the amino acids attaches to the tRNA are placed in sequence according to the sequence of codons in mRNA
translation: amino acids of tRNA in sequence
amino acids joined by a peptide bond to make a protein (polypeptide chain)
translation: once protein is made
tRNA molecules separate from their amino acids and the mRNA and return to the cytoplasm
translation: when tRNA return to the cytoplasm
they continue to pick up their specific amino acid and return to bind with mRNA until a stop codon is reached
translation: when a stop codon is reached
the amino acid sequence of the new protein is complete
translation: when protein is made
folds into its functional 3D shape
translation
the use of the base sequence (codons) in mRNA to place amino acids in sequence to make a protein
to isolate DNA from a plant tissues
what plant
onion
to isolate DNA from a plant tissues
what do you do with the onion
add onion to a beaker with salt and washing up liquid
to isolate DNA from a plant tissues
what do you with the beaker
put in a water bath at 60ºC for exactly 15 minutes
to isolate DNA from a plant tissues
after you have heated the beaker
cool by standing in a an ice water bath for 5 minutes, stirring frequently
to isolate DNA from a plant tissues
after mixture has cooled
pour into a blender and blend for a few seconds
to isolate DNA from a plant tissues
after blending
filter the mixture into a second beaker
DNA is in the filtrate
to isolate DNA from a plant tissues
you have filtrate
add 2-3 drops of protease to the filtrate and mix gently
to isolate DNA from a plant tissues
once protease is added
trickle ice cold ethanol down the side of the boiling tube to form a layer floating on top of the filtrate
to isolate DNA from a plant tissues function of ethanol
separates the DNA from the filtrate and make it visible
to isolate DNA from a plant tissues
when you have put the ethanol in
leave for a few minutes without disturbing it
to isolate DNA from a plant tissues
what do you observe
DNA at the interface (boundary) of alcohol and filtrate
to isolate DNA from a plant tissues
how do you remove DNA
with a glass rod
describe the structure of DNA (L.C)
double helix
phosphate with nitrogenous bas and deoxyribose
in nucleotides with hydrogen bonding between bases
describe the role of DNA in heredity (L.C)
has genetic code
can be replicated and passed on to next generation
base sequence is significant
variation (L.C)
differences between individuals
mutation (L.C)
change in genetic material (genotype)
why may variation result from a mutation (L.C)
change in genotype may result in an inheritable variation
state 2 agents possible for mutation (L.C)
radiation
chemicals
viruses