How DNA forms Chromosomes and other important information Flashcards
purines
double rings such as Adenine Guanine
Pyrimidine
single ring thymine cytosine
what is a Glycosyl
A glycosidic bond exists in the DNA molecule between sugar and nitrogen base.
Chromatin consists of approximately ___ protein and ___ DNA
60% and 40%
a chromosome is a long strand of ____ and ______ made of _______ nucleotides
DNA and Protein and 300 million
how are chromosomes organized
what is a nucleosome
how is the DNA double helix strand strongly attracted to the histones
what do series of nucleosomes do
and what happens after
so the DNA is coiled to fit inside nucleus and every 200 nucleotides the DNA double strand is coiled around a central histone ( 8 histones together) and is held by another histone (Hi)
nucleosomes are complex of histones coiled by DNA
it has a negative charge and therefore meaning histones have positive charges
series of nucleosomes coil into chromatin fibres
chromatin fibres fold and supercoil
humans contain how many of what chromosomes
46 ( 44 somatic, 2 are sex chromosomes)
how many genes exist within the human genome
42 000 and 95+ is noncoding
what are VNTR’s (variable number tandem repeats) and where can they be located
and what are they also known as
VNTR’s are sequences of base pairs that repeat, the length varies as does their position within the genome
you can find them in noncoding regions
also known as microsatelites
what are introns and exons
introns are sequences of DNA removed from the mRNA transcript
and do not code for a protein
exons are genes which do encode the amino acid sequence for protein production
what is a telomere
long sequences of repetitive noncoding DNA are found at the ends of chromosomes, called telomeres, to serve and protect DNA from losing nucleotides during replication
what is the monomer of DNA
Nucleotide
but can also be polymers when joined together
why is DNA called deoxyribonucleic acid instead of ribonucleic acid
because there is no oxygen at the second carbon of deoxyribose sugar
what is the bond name that attaches the rungs of the ladder to the sides of the ladder
glycosyl bonds as it is between deoxyribose sugar and nitrogenous base
