DNA And The Genome Flashcards
Structure of DNA
Nucleotides. Sugar phosphate backbone, A-T C-G, hydrogen bonds between bases. Double stranded antiparallel structure. Deoxyribose sugar and a phosphate. 3’ end abdominal a 5’ end. Double helix.
Prokaryotes have …..
A single circular chromosome and smaller circular plasmids
Eukaryotes have ….
Liner chromosomes tightly coiled and packed with histone proteins. They also have circular chromosomes in mitochondria and chloroplast. Yeast is special as it also has plasmids
What does DNA polymerase do in the replication of DNA?
Adds DNA nucleotides using complementary base pairing to the deoxyribose 3’ end of the new DNA strand. Ligament joins the strands together
What does RNA splicing do?
It forms the nature mRNA transcript
How is the phenotype determined?
By the proteins that are produced by gene expression
What is cellular differentiation?
The process by which a cell expresses a certain gene to produce a particular protein, which carries out a specific function
Embryonic stem cells are ….
Pluripotent
Tissue stem cells are….
Multipotent
Single gene mutations
Substitution
Insertion
Deletion
What can nucleotide substitutions lead to? (3 types of final results)
Missense- different amino acid produced
Nonsense- stop codon
Splice-site- some introns kept and some exons left out
Simple DNA replication
Double helix unwinds and hydrogen bonds break.
RNA primes join on the 3’ end. One on the leading strand and multiple on the lagging strand.
DNA polymerase adds nucleotides continuously on the leading and in fragments on the lagging.
Ligase then seals the sugar phosphate backbone together.
Components needed for PCR (5)
Buffer
Nucleotides
Primers
Polymerase and ligase
Template DNA
In PCR primers are…
Short strands of nucleotides which are complementary to specific target sequences.
Process of PCR
- Heated to 92-98* and the strands split
- Cooled to 50-65* primers attach to the single strands
- Heated to 70-80* heat tolerant DNA polymerase binds to primers and adds nucleotides to the 3’ end
- Heated to 92-98* again
- Cooled to 50-65* primers now bond to original fragments and copies
- Heated to 70-80* heat tolerant DNA polymerase copies the DNA again
Uses of PCR
-forensic science
-disease detection
-population studies
-phylogenetics
-early detection of infection
3 differences of RNA to DNA
Single stranded
Ribose sugar
Uracil replaces thymine
3 types of RNA
Messenger
Transfer
Ribosomal
mRNA
Carries a copy of DNA from the nucleus to the ribosome
tRNA
Collects amino acids acids and takes them to the ribosome to be used in translation
rRNA
Combine with proteins to make ribosomes
Definition of stem cells
Unspecialised cells in animals that can self-renew and can differentiate into specialised cells
Cellular differentiation is the process….
By which a cell develops to do a more specialised function by switching on or off certain genes
What are meristems
Areas of differentiation into specialised cells in plants
Embryonic stem cell
Early embryos
Pluripotent
Tissue stem cells
From adult red bone marrow
Multi potent
Therapeutic uses of stem cells
Repair damaged or diseased organs or tissue (skin graphs, corneal transplants)
Ethical issues
Some people believe it’s the destruction of a human life
But it removes the use of animal testing
Research uses of stem cells
To detect diseases
What does alternative RNA splicing allow for?
The same gene to be used to make several different proteins.
what is genomic sequencing
the ordering the sequence of nucleotide bases in a genome
what is bioinformatics
analysis of sequence data using computers and statistics
what is phylogenetics
study of evolutionary relatedness of species
what is a molecular clock
its a graph that shows differences in sequences data for nucleic acids or proteins over time
what is sequence data
information about nucleotide base sequence and/or amino acids
what are the 3 domains of life
bacteria
archaea
eukaryotes
what is personalised medicine
treatment what is based upon an individuals own genome sequence
what is pharmacogenetics
the use of genome information in the choice of drugs
