Molecular Genetics-Levels of Organization+Definitions Flashcards
How big is one base pair/distance between each base pair in a double helix
0.34nm
How many bps make one turn of DNA
10
How long is one turn
3.4nm
How wide is the DNA double helix
2nm
LEVELS OF ORGANIZATION
Width of DNA molecule
level 1
2nm
Histone+146 bp of DNA=nucleosome, appears as beads on a string
LEVELS OF ORGANIZATION
Width of Histone+DNA
level 2
11nm
Makes them organized
LEVELS OF ORGANIZATION
Width of Solenoid
level 3
30nm
nucleosome beads are tightly packed, forming chromatin fibre held by H1
LEVELS OF ORGANIZATION
Width of Euchromatin
level 4
300nm
Forms loops connected to proteins in the nucleus
LEVELS OF ORGANIZATION
Width of Heterochromatin
level 5
700nm
condenses into chromosomes, further fold the chromosome’s scaffold
LEVELS OF ORGANIZATION
Width of Total Chromosome
level 6
1400nm
Become duplicated & held 2gether by a centromer forming sister chromatid
Which Bases always pair in double stranded DNA
Base Pairing
A+T
C+G
IN Purine: (A+G), Pyrimidine: (C+T)
DEFINITIONS
GENE
- Basic unit of heredity that determines genetic traits
- Specific sequences of Dna that encodes and may influence production of proteins & RNA molecules
DEFINITIONS
GENOME
- An organism’s complete genetic makeup
DEFINITIONS
NUCLEOID
- Dense region where DNA is tightly packed through super coiling
DEFINITIONS
SUPERCOILING
- When DNA molecule twists/coils upon itself
DEFINITIONS
TOPOISOMERASE
- Enzyme
- Helps with either coiling a DNA or relieves tension of the DNA by untwisting it
DEFINITION
HISTONE
- Group of proteins around DNA coils
DEFINITION
NUCLEOSOME
- Histone+142 bp of DNA
Name for this^
DEFINITION
SOLENOID
- Nucleosome “beads” tightly packed to make chromatin (solenoid fibre)
- Held by another histone protein (H1)
How is DNA packed
- DNA gets packed into the nucleoid region through super coiling
- Topoisomerase coil these coils
- Specialized proteins help hold the coils
CHARGAFF’s RULE MATHEMATICALLY
What are the relationships between Adenine, Guanine, Cystosine & Thymine with Chargaff’s math rules
A=T, C=G
A+G=50
C+T=50
Equation: (A+G=C+T)