Notes 5 & 6 Flashcards
1kb=
1000 base pairs
1 Mb=
1,000,000 base pairs
premRNA also known as
heterogenous nuclear RNA
3 ways genes can code for multiple proteins
- Alternative starts and stops
- New reading frame
- Splicing
Genome
complete set of sequences in genetic material of organisms
includes DNA in chromosomes and mitochondria
Transcriptome
Set of RNA present in a cell, tissue, or organism
Complexity due to mRNAs
Will vary depending on tissue
Proteome
set of proteins expressed by entire genome within a cell at any one time
why kidneys look nothing like heart
depends on tissue
Interactome
complete set of protein-protein interactions
Metabolome
metabolites: glucose, pyrivic acid, lactic acid
Little molecules that make us work
Linkage Maps
based on frequency of recombination between genetic markers
Linkage break
more likely to occur between genes that are further apart
Restirction Map
get different band sizes based on where restriction site cut
Which exon sequences are more likely to be toward each end
AG at 5’
GT at 3’
synteny
pieces of other organisms are in our genome (conserved, linked sequences)
mouse and human chromosomes show conserved regions
What organelles are maternally inhertied
Mitochondria and chloroplasts
Why are they easy to map?
There isn’t recombination
3 things our mitochondria code for
13 proteins
2 rRNAs
22 tRNAs
D-loop
where the origin of replication is in mitochondria
Can be variable in size and sequence
Endosymbiant Theory
Mitochondria used to be bacteria.
Went in cell for protection and in exchange they gave energy
Characteristics of mitos
Circular DNA
Usually only get one single transcript
Have own ribosomes
For bacteria, ______ relates to ________
genome size relates to gene number
Does genome size relate to gene number for eukaryotes?
NO
Moncistronic
codes for one polypeptide
Polycistronic
mRNA has regions representing more than one gene
Gene families
Genes with conservd functions and similarities, like histones
The larger the genome, the….
more gene families
What % is protein encoding in the human genome?
1%
How does only the 25-30,000 genes encode for more?
Alternative splicing (mRNA), alternative starts/stops, modification via phosphorylation, glycosylation, acetylation, and methylation
Transposons
genes that jump around
Most are evolutionary remnants
Alu sequences
evolutionary transposons that are very large
SINE
short interspersed nuclear elements
LINE
long interspersed nuclear element
What’s special about the Y chromosome
The genes are highly conserved and maintained in multiple copies. There is gene conversion so a mutation in one of them may not have effects
Differential gene expression
10,000 genes change function
Can be specific to a certain area
Housekeeping gene
expressed in a cell because it provides basic functions needed for sustenance
Example: cytokinesis and ribosomal proteins, histones, phosphofructose kinase
M chromosome
has centromere in middle
known as metacentric
Sub-M chromosome
Has centromere more towards one side
Sub-metacentric
A chromosome
has centromere far towards one side
Acrocentric
Chromo and soma mean..
color
body
How did chromosomes get their name?
Stain darkly with aniline dyes
P arm
short arm of chromosome
Q arm
long arm of chromosome
Holocentric chromosomes
have multiple copies of chromosomes along their entire length
multiple spindle fibers with diffuse centromeres
Monocentric chromosomes
only one centromere
Contemporary definition of cytogenetics
techniques of cytology and molecular biology used to study heredity
Karyotype
complete set of chromosomes
Condensed metaphase chromosomes
used for research
first human chromosome sequenced
number 22
How was the first chromosome sequenced
BAC and YAC sequencing
Specifically used BAC since a YAC one could’ve recombined with the human sequence
Shotgun random sequencing
Developed by Celeragenomics where they sequenced the whole genome
Was used to complete 180 Mbp gene of D. melanogaster
