Storing using genetic information Flashcards
Define phenotype
the outward physical genes expressed
Define genotype
The full hereditary information of an organism
What is DNA a chain of
Nucleotide monomers
What is a nucleotide composed of
Deoxyribose
Base
Phosphate group
Why is it deoxyribose the sugar in DNA
Bonds are more attracted to each other due to reduced polarity making DNA more stable as harder to separate
what is the structure of DNA
and the direction
Double helix
right hand twist
What are the four bases of DNA
Adenine
Guanine
Thymine
Cytosine
What are the bonds that join the bases
and What is the the pairing of DNA bases
Hydrogen
Adenine - thymine
Cytosine - guanine
What maintains the shape of the DNA double helix
Sugar phosphate backbone
Where does DNA replication take place
Nucleus
What direction is DNA synthesis
5-3 direction
What are the steps of DNA replication
- Enzymes break hydrogen bonds and DNA unwinds
- New nucleotide molecules pair with two DNA strands
- Replication occurs in 5-3 direction by enzyme DNA polymerase on leading strand
- Lagging strand replicated in fragments which are then joined by DNA ligase and DNA polymerase adding on Nucleotides
What does it mean that DNA is bidirectional
5 prime to 3 prime DNA run antiparallel to each other
What is the fragmentation called in DNA replication
okazaki
How is DNA replication semi-conservative
one half of DNA made is new where the other strand is old DNA
What are the codon region in DNA
exons
How is the base sequence of DNA transcribed into RNA
- mRNA enters nucleus and transcribes DNA with nucleotides coding only with the exons
- mRNA then is transported out of the nucleus into the cytoplasm
What is it called when mRNA only codes exons and eliminates introns
alternative splicing
What happens post transcription
The base sequences frames are read and segmented into each 3 bases create a codon specific for a particular amino acid
What happens in the translation of mRNA
- mRNA binds to ribosomes (rRNA) in the cytoplasm
- tRNA binds anticodons to mRNA coding sequence
- tRNA then brings in specific amino acids
- passes amino acid along forming peptide chain
- Peptide chain is then transported to golgi apparatus where they are synthesised and packaged into proteins
Where is ribosome/rRNA produced
nucleus
What is degeneracy
more than one codon codes for an amionacid
What can a single point mutation cause
dysfunctional protein
Example of a single point mutation
sickle cell anaemia
what is a polysome
several ribosomes translating mRNA at the same time
