DNA and Protein Synthesis Flashcards
Bases
adenine - thymine
guanine - cytosine
nucleotide
consists of one sugar, phosphate and nitrogenous base
DNA replication
- two strands of DNA separate
- the strands act as a template
- complimentary bases pair up with the template bases
- results in two identical DNA molecules
protein synthesis
the sequence of bases in a gene dictates the sequence of amino acids, therefore what protein will be produced
- complimentary mRNA makes a template of the base sequence (transcription)
- mRNA molecule moves into the ribosomes
- codon (3 bases) dictates the type of amino acid
- tRNA brings correct aa, join to create a protein (translation)
Mutations
a permanent change to the base sequence in a DNA strand
a different protein can change the phenotype of the cell or organism
mutations can be advantageous, disadvantageous or have no effect
Epigenetics
explains why genetically identical cells/organisms aren’t identical in appearance or function
Methylation
methyl groups being added to the cytosine base causes the DNA to become more tightly around the histone
de-acetylation
the removal of acetyl groups, causing the DNA to be more tightly wrapped around the histone
environmental tags
environmental factors can be responsible for epigenetic changes
eg. cigarette smoke can methylate or de-acetylate the histones; therefore the gene that prevents lung cancer is turned off
DNA profiling
a technique used to distinguish between individuals using samples of their DNA
Stages in DNA profiling
- samples are collected
- DNA is removed
- Polymerase Chain Reaction used to duplicate DNA
- Restriction enzymes are used to cut the DNA at a certain point
- gel eletrophoresis produces a pattern unique to each individual
DNA structure
major components are sugars, phosphates and bases
sugar and phosphate make up the backbone of the molecule
between the sugar molecules are bases
