Unit 1 Key Area 1-3 Flashcards
What is DNA is composed of
Two chain of nucleotide
Base pairing rule
Adenine pairs with thymine
Guanine pairs with cytosine
Definition of a nucleotides
They are comprised of deoxyribose sugar, phosphate and a base
What the name of the bond between the deoxyribose sugar and phosphate
Sugar- phosphate bond
What are the bonds between the bases called
Weak hydrogen bonds
Two classification of cells
Prokaryotes
Eukaryotes
Where are mitochondria and chloroplast DNA inherited from
From the mother
Are mitochondria dna circular or linear
Circular
DNA is inside of what
Chromosomes
Two types of strands
Lagging and leading
DNA replication is
Semi-conserivate
What does semi-conserivate mean
It has one old parental strand and one new one
Where do polymerase add nucleotides
At the 3’end
In the leading strand
Dna polymerase adds complementary DNA nucleotides to thr lead strand continuously
Stages of the leading strand
- The weak hydrogen bonds break and the DNA unzips
- A DNA primer binds to the end of the 3’ to allow polymerase to add the DNA nucleotide
- Individual nucleotides aline wirh there complementary base. They become joined 3’ end of the primer.
Polymerase brings about thr formation of the sugar-phosphate bind between the primer and nucleotide.
How does lagging strand work
DNA polymerase adds complementary nucleotides to lagging strand in fragments
What sort of process is lagging strand
Discontinuous
What does ligase do
Seals the fragments together in the lagging strand
Where do primers bind yo leading strand
At the bottom in one place
At the 3’ end
Where do primer add to at the lagging strand
They bind at many places
DNA replication requirement
DNA
primer
Nucleotides and bases
DNA polymerase and ligase enzymes
A supply of atp
What does PCR allow
A specific section of DNA to be amplified in vitro
Steps of PCR
Step one. DNA is heated to 95°c this causes DNA to denatured and the strands separate
- DNA is cooled to 55°c for a few seconds. This allows primers to to bond to the separated DNA strands
- DNA is heated up to 75°c this allows heat-tolerrant DNA polymerase to replicate the dna be adding nucleotides to the 3’ of thr original DNA
How many times is PRC repeated
20-30 cycles
What is amplification
Doubling DNA
Uses of PCR
Forensic science
Disease detection
Requirements for PCR
Sequence specific primer
Supply of nucleotides
DNA sample
DNA polymerase
Thermocycler
What our 3 differences between DNA and RNA
RNA is single strand and DNA is double stranded
RNA ribose sugar and deoxyribose is DNA
Uracil is RNA and DNA is thymine
Three types of rna
Messager RNA mRNA
transfer RNA tRNA
Ribosomal RNA rRNA
MRNA
Mrna is formed jn the nucleus from free nucleotides and carries a copy of thr dna code from the nucleus to the Ribosome where proteins are made
Trna
Molecules collect amino acids and bring them to the Ribosome to build proteins into a 3d structure held together hu hydrogen bonds
RRNA
Molecules combined with proteins to create the ribosomes. The organelle responsible for assembling proteins following DNA code
Are the two strands of dna parallel or anti parallel
Antiparallel
Are the two strands of dna parallel or anti parallel
Antiparallel
What does antiparaelle mean
Each strand runs in the opposite direction of thr complementary
What type of backbone do they have
A sugar phosphate backbone
What type of backbone do they have
A sugar phosphate backbone
What’s the bond between phosphate and deoxyribose sugar
Sugar phosphate bond
What is at the 5’ end
Phosphate
What is at the 3’ end
Deoxyribose sugar
What time of chromosomes are in eukaryotes
Linear chromosomes
Type of eukaryotes
Plants, animals and fungal
One structural difference between eukaryotes and prokaryotes
Eukarytoes are a nucleus
In what places in rhe cell so eukarytoes have circular chromosomes
Mitochondria and chloroplast
Where is dna found in the prokartoes
Cytoplasm and plasmid
What type of chromosomes do prokarytoes have
Circular
Yeast cells
Have circular chromosomes in the plasmid and cytoplasm
How is the DNA stored
They are tightly coiled and packaged around histone proteins
Step 1 in DNA Replication
The DNA parental strand composed of two complementary strands unwind
Step 2 in DNA replication
The weak- temporarily hydrogen bind between bond break
Step 3 in DNA replication
Two new template strands form exposing bases. The DNA strands separate
Step 4 DNA replication
Primers attach to the 3’ end and free nucleotides bind wirh their base pair by new weak tempary hydrogen bonds
Step 5 in DNA replication
The nucleotides are added by the enzyme DNA polymerase which forms the sugar-phosphate bonds making the sugar backbone
Step 6 in DNA replication
Two new identical stands have formed and DNA rewinds
5 things required for DNA replication
DNA template
Free DNA nucleotides
Chemical emgery in the form of ATP
Primers
Enzymes
When duration does the DNA polymerase go from
3’ to the 5’
Is the leading strand continous or discontinuous
Continous
What’s the role of DNA ligase
Is to join DNA fragments together on the lagging strand
Is the lagging strand continous or discontinuous
Discontinuous
State 2 roles of DNA primers during replication
Allow a start point for replication
Each primer targets on a different strand
State the role of DNA polymerase
Binds complementary nucleotides to the DNA at the 3’ end of the DNA strand
State why the antiparallel nature rreudltd in one strand beung in short fragments
Nucleotides can only be added to the 3’ end
Explain why cells need to carry out DNA replication
So that the exact copy of the genetic material is passed to the new daughter cells
Explain why the DNA polymerase used can function at 70°c
Come from a bacteria adapted to live in hot springs
Whixh form of cell does not have q membrane bound organelles
Prokaryptes
Which form of cell does have membrane bound organelles
Eularytoes
Step 1 of PCR
The dna strand is heated to 92-98°c this breaks the weak hydrogen bonds between the bases and separate rhe DNA strand
Step 2 of PCR
The sample is cooled to 50-56c. This allows the short primers to bind to the separate strands
Step 3 of PCR
sample is heated to 70-80c
This allows the heat tolerant DNA polymerase to replicatate by adding the nucleotides to the 3’ end of the original strand.
Step 4 of PCR
The end of the process and it is then repeated
Where is PCR carried out
Thermicycler
What is PCR
This is a technique used to create many copies of fragments of DNA in a vitro laboratory setting.
What is PCR
This is a technique used to create many copies of fragments of DNA in a vitro laboratory setting.
Uses of PCR
Forensics
Paternity
Disagonided
What happens to the number if copies
To doubles every time
What happens to the number if copies
To doubles every time
What is gel electrophoresis
A process used to separate DNA fragments. Using agarose gel.
What is gel electrophoresis
A process used to separate DNA fragments. Using agarose gel.
PCR requirements
DNA template
Primer
Supply of nucleotides
Ph buffer
Heat tolerant DNA polymerase
Thermal cycler machines
PCR requirements
DNA template
Primer
Supply of nucleotides
Ph buffer
Heat tolerant DNA polymerase
Thermal cycler machines
What is RNA
It is a single stranded genetic molecule made up of repeating RNA nucleotides
What type of sugar does RNA have
Ribose sugar
What are the bases got RNA
Adenine, guanine cytosine and uracil
Difference in DNA AND RNA
Dna is double rna is single
Dna us deoxyribose and rna is Ribosse
Dna is thymine and rna us urcel
Difference in DNA AND RNA
Dna is double rna is single
Dna us deoxyribose and rna is Ribosse
Dna is thymine and rna us urcel
3 types of RNA
mrna
TRNA
rRNA
Mrna
Carries a copy of DNA of dna code from the nucleus to the Ribosome
That us tENA
Carries a spficic amino acids to the Mrna at the Ribosome
rRNA
Along with proteins from the Ribosome
What is a phenotype
The apparence of an organism
What is a gene
The appearance that codes for a protien
What’s allele
Different forms of the same gene
What’s a genotype
The particular allele of genetic material
What is transcription
It copies the parental DNA strand into mRNA in order for ut to leave thr nucleus and travel into the Ribosome
Stage 1 of transcription
DNA unwinds and unzips by the RNA polymerase and weak hydrogen bond are broken between the strands so therefore the complimentary bases are exposed
Stage 2 of transcription
RNA polymerase joins Free RNA nucleotides with their complementary bases on the DNA strand
Stage 3 in transcription
Temporary weak hydrogen bond form between the complementary bases
Adenine with uracil
Cytosine with guanine
Stage 4 transcription
RNA polymerase links the RNA nucleotides together to form a strong sugar-phosphate backbone
Stage 5 in transcription
The weak hydrogen bond between RNA and DNA break the DNA rewinds and the hydrogen binds between strands reunite. The single mRNA is called the primary mRNA transcription. This primary mRNA transcript under goes RNA splicing
What are introns
Non coding regin of DNA
What are Exons
Coding region for DNA
How does RNA splicing work
The introns are removed from the mRNA primary transcript and then the axons are put together
Why does thr order of the axons matters
Different orders code for Different proteins.
How does the mRNA leave the nucleus
Through the nucleus pores
Where does translation happen
It happen in the cytoplasm at the Ribosome
Where does translation start
At the start codon
Start codon code
AUG
Each group of 3 codes for how many amino acids
1
Step 1 of translation
mRNA has left the nucleus and gone to the Ribosome going through the cytoplasm. It then attaches to the Ribosome
Set 2 in translation
tRNA has an anticodon and an amino acid atachment site. tRNA picks up a spefic amino acid and transport it to the mRNA strand
Step 3 in translation
The codon on the mRNA binds with thr anti-codon on the tRNA using the complimentary base pairing. Starting at the start codon and ending with the stop codon
Step 4 in translation
Amino acids bind together with peptide bonds to make a polypeptide
Step 5 in translation
tRNA leaves the Ribosome as the polypeptide is formed to get another amino acid this continues until STOP codon is encountered.
How can a variety of proteins be expressed from 1 gene
This is due to alterative RNA splicing
What does a stop codon do
It halts the protein synthesis and divides the production of two different proteins
What to proteins do after they form their polypeptide binds
They fold together to make a 3D structure
What is the function of a protien determined by
Rhe shape it has
What bonds does the protien have when it has irs chnage
Hydrogen bonds and other interactions
What bonds does the protien have when it has irs chnage
Hydrogen bonds and other interactions
Two roles of RNA polymerase
To ubwind the DNA and break the weak hydrogen binds between the DNA nucleotide
Join up the RNA nucleotides tides to make the primary transcript
What type of cells to humans have
Eukaryotes
What type of cell bacteria
Prokaryotes
What are the importantance of an anti-codon
So that a specific amino acid is used
What shape of chromosomes do eukaryotes have
Linear
But circular in mitochondria and chloroplast
We’re is DNA found in prokaryotes and yeast cells
Plasmids and cytoplasm
What shape of chromosomes do prokaryotes have
Circular
Describe the process of alternative splicing
Different axons are joined together in the mature transcript
Describe the process of alternative splicing
Different axons are joined together in the mature transcript
RNA slicing
Exons are the coding region and introns are the non coding. The Intrond are removed and the axons are retained. Axons are spliced together to form the mature transcript
Explains why cells need to carry out DNA replication
To that exact copies of genetic material is pasted in to daughter cells
Describe one way in which a polypeptide could be modified
Cut and combine polypeptide
