| X shaped chromosome | is a sister chromatids made by dna replication |
| X shaped chromosome | is a sister chromatids made by dna replication |
| What monomer is DNA made up of | nucleotides |
| What is a nucleotide made of ? | - deoxyribose sugar
-phosphate
-base |
| What is polynucelotide | a phosphodiester bond form between the nucleotides - so many nucleotides |
| How polynucelotides formed? | condensation reactions |
| How many polynucelotides made out of | 2 |
| Why do bases join together? | complementary |
| what bonds join base pairs? | hydrogen |
| Describing the structure of DNA | DNA is made up of deoxyribose sugar, phosphates , base .
they are 4 types of bases ATCG
nucleotided are joined by condensation to form a polynucleotide and phosphodiester bonds form. DNA is made up of 2 polynucleotides strands together , the strands are join together by hydrogen bonds between complementary base pairs , pairs with the base pairs. Dna is called a double helix. |
| Function of DNA | DNA contains a genetic code - sequence for bases that code for specic proteins. |
| What is DNA replication? | a process where DNA is used to make 2 genetically identical molecules/strands of DNA |
| Where does DNA replication occur? | Eukaryotic - nucleus
prokaryotic - cytoplasm |
| When does DNA replication occur ? | Interphase - first part of the cell cycle in particulary the s phase of interphase - eukaryotic
when cells divide in binary fission - prokaryotic |
| Enzymes required in dna replication | DNA HELICASE (Breaks hydrogen bond between base pairs leaving template strands) AND DNA POLMERASE ( work on the backbone forming phosphodiester bonds joining nucleotides) |
| DNA replication trigger words | Break
template
new strand
identical
semi conservative |
| Dna replication full process | DNA Helicase (enzyme) separates DNA strands.
By breaking hydrogen bonds between the complementary base pairs.
Both of the separated strands act as template strands.
Free DNA nucleotides bind to the template strands by complementary base pairing.
A pairs with T and C pairs with G.
Hydrogen bonds reform.
DNA polymerase joins the nucleotides together by forming the sugar-phosphate backbone. Condensation reactions occur forming phosphodiester bonds.
Two genetically identical molecules of DNA are produced.
This is semi-conservative replication because the DNA is made up of one original strand and one new strand. |
| formula for calculating the number of DNA produced | 2n
2= value not changes
n= change number for the number of cycles of replication |
| X shaped chromosome | is a sister chromatids made by dna replication |
| Key defintions of DNA | DNA triplet - 3 DNA which code for an amino acids
start triplet - first 3 dna bases
stop triplet - last 3 dna bases which does not code for an amino acid |
| what is the ratio for amino acid | 3:1 |
| Degenerate code | more than one rriplet code for the same amino acid |
| What is TRNA structure? | - single polynuceloide strand made up of nucleotides ( phosphate, ribose,AUCG) folded into a clover leaf shape.
- some parts of TRNA are joined by complementary base pairs joined by hydrogen bonds
- each trna has 3 exposed bases called anticodons
- each trna has an amino acid binding site. |
| Key things about DNA when comparing | Double
deoxyribose
CONTAINS PHOSPHATES
ATCG Bases
hydrogen bonding
double helix shape
found in the nucleus |
| key things about mrna when comparing | single stranded dna
ribose sugar
contains phosphates
AUCG
long and straight chain
found in the nucleus and cytoplasm |
| key things about tRNA when comparing | single stranded
ribose sugar
phosphates
AUCG
hydrogen bonds
amino acid attached
clover leaf shape
has an anticodon
found in cytoplasm |
| Why is mrna and trna and dna and ribosomes needed to make proteins | DNA contains the code for making proteins.
Amino acids are needed – these are found on the tRNA.
Ribosomes are where proteins are made.
mRNA - Ribosomes need the genetic code but DNA is too big to leave the nucleus so mRNA copies the DNA code and sends the message to the ribosome. |
| Translation trigger words | mRNA attaches
tRNA
tRNA attach
ribosomes move
stop codon
polypetide produced |
| Translation theory | mRNA attached to a ribosome (at the start codon). tRNA has a specific amino acid attached to it. tRNA has an anticodon which is 3 exposed bases.A tRNA binds to mRNA at the ribosome
– the tRNA anticodon binds to the codon on mRNA by complementary base pairing and forms hydrogen bond.
Another tRNA binds to the second codon on mRNA.
A peptide bond forms between the amino acids.
The ribosome moves along the mRNA (more tRNA anticodons base pair with mRNA codons).
This process continues until a stop codon is reached. The polypeptide produced detaches from the ribosome and mRNA. |
| Differences between translation and transcription | Transcription - nucleus
Dna helicase
free mrna nucleotides
RNA polymerase
Translation- cytoplasm
ribosomes
tRNA |
