DNA 𧬠Flashcards
What is dna
DNA is made up of two strands of nucleotides joined together by bases.
When this structure is twisted it forms a double helix
What are the names of the four bases
Adenine Guanine Cytosine Thymine
Which pairs of bases always pair up together
A - T
C - G
What is the way of pairing up the bases known as
Complimentary base pairing
How many hydrogen bonds are there between cytosine and guanine
3
How many hydrogen bonds are there between adenine and thymine
2
What is hydrogen bonding
Parts of the dna bases gave a slight electrical charge
A positive part of one base attracts to a negative part of another
This forms a weak force of attraction called a hydrogen bond
What are the small units that make up dna called
Nucleotides which are joined up together to form a polymer
What is a nucleotide made up from
A base, a deoxyribose sugar and a phosphate group
What are the 2 stages in which dna stores the genetic code for building proteins
Transcription and translation
What does RNA stand for
Ribonucleic acid
What is RNA
A single strand of the dna
What happens in transcription
The dna bases are used to make a strand of RNA, occurs in the nucleus
What is RNA polymerase
An enzyme that unzips the dna
What is the non coding binding site
An area that does not contain code for protein
What is a template strand of dna
Free RNA nucleotides bind to this dna strand
What is a non template strand of dna
Codes for the template strand of dna
What is mRNA (messenger rna)
A form of RNA inside the ribosomes
What happens in translation
mRNA travels out of the nucleus through nuclear pores and into the cytoplasm where it attaches to ribosomes
What is a codon
A triplet of bases that code for amino acids
What is tRNA (transfer RNA)
A form of RNA that carries specific amino acids
What is a polypetide
A chain of amino acids which then folds up to form a protein
What is the sequence for DNA protein synthesis
DNA-transcription-mRNA-translation-amino acid chain
How can DNA be extracted from fruit
Mash up a kiwi fruit
Mix with a teaspoon of salt and small volume of washing up liquid
Gently heat at about 60Β°οΏΌ for five mins
Filter retaining only thr filtrate
Cool in ice bath and pour ethanol on top
Why was the 3 domain classification proposed instead of the 5 kingdoms
Based on fundamental differences in DNA rather than characteristics
What is tissue culture
A way of cloning plants
Method for tissue culture
Tissue sample from parent plant is placed in agar growth medium containing nutrients and auxins
Samples develop into tiny plantlets
Plantlets planted into compost
