Lecture 14 Flashcards
Total amount of DNA in a human cell
6.4x10^9 base pairs
(cuz human cell is diploid)
Total amount of DNA in human genome
3.2x10^9
How many autosomes do we have?
22
What DNA types are included in the human genome?
22 +X +Y +mitochondrial
Total length of human DNA?
2.176m
Length of nucleus in a typical eukaryotic cell
6 to 7micrometers
What stage of mitosis does DNA Replication occur?
Interphase
Steps of mitosis?
Interphase, M phase, interphase
What happens at interphase?
chromosome loosened, gene expression and DNA replication occurs
3 parts of chromosome needed for replication and
separation of chromosomes
during cell division
Origin of Replication
* Telomeres (telomere=TIPS)
* Centromeres (center of chromosome)
How many genes in 10% of a chromosome arm?
40 genes
How many nucleiotide pairs in a gene?
3.4x10^4 nucleiotide pairs
What is a mitotic chromosome?
Hint: what stage does it happen?
When mitotic spindle is attached to centromere.
(think mitotic spindle coming to snatch duplicated parts way from each other). During M phase
Height of a histone?
11nm
How many times does DNA wrap around histone?
1.7 times
How many base pairs of DNA on histone core?
147bp
What is a nucleosome?
Histone with DNA wrapped around
Width of Beads on a string structure of a histone?
11nm
Parts of octameric histone core?
H2A, H2B, H3, H4
Width of chromatin fibre?
30nm
What are the tails on the histone made of?
Proteins (amino acid chains)
What does the N terminal in the histone tail allow it to do?
These tails bind to other nucleosomes as well as non-histone proteins
Chromatin fibre vs chromatin fibre loops?
Fibre= many nucleoosomes packed together
fibre loops= chromatin fibres folded into loops
Size of chromatin fibre loops
700nm
