Structure and function of human genome Flashcards
For chromosome, what does p arm mean?
Short arm
For chromosome, what does q arm mean?
Long arm
What are the types of chromosomes called in order?
1) metacentric
2) sub-metacentric
3) acrocentric
4) telocentric
What ways do scientist use to identify different chromsomes?
1) size
2) banding pattern
3) centromere position
How many histones are needed to form a nucleosome?
8 (octamer of histones)
linker dna leads to the next nucleosome
When DNA wraps around histone molecules and there are multiple nucleosomes what structure does it create?
Solenoid structure
What is a chromatin that is in an extended state, dispersed through the nucleus and allows gene expression?
Euchromatin
What is a chromatin that is highly condensed and genes not expressed?
Heterochromatin
What are 2 unique characteristics and functions of centromeres?
1) Rich in heterochromatin
2) highly repetitive
What are the protein coding gene called? (1.5%)
Exome
What are the protein coding gene called? (1.5%)
Exome
Which part of exons don’t code for amino acids?
The untranslated regions like the 5’UTR & 3’UTR
What are UTR?
It is untranslated regions that contain regulatory elements (important for control of protein synthesis)
What is a nuclear genome?
It is made out of 22 pairs of autosomes and 1 pair of sex chromosomes.
Transcribed unit = genes
- Protein coding
-RNA only coding (non coding transcripts that make RNA but not protein)
What is a mitochondrial genome?
Every mitochondria has the mitochondrial genome.
- 16Kb compared to 3000 Mb (nuclear genome)
What is your genome?
1) Material =
2) Packages =
3) Genes? =
4) Just genes? =
5) How big is it? =
6) All DNA in cell (nuclear) and mitochondrial DNA? =
1) DNA
2) Chromatin and chromosomes
3) Yes
4) No
5) Big
6) Yes
What bases are purines?
Adenine and Guanine
What bases are pyrimidines?
Cytosine, Thymine and Uracil
What is an epigenome?
Chemical compounds that attach to DNA or histones and can affect gene activity (DNA methylation and histone acetylation)
What can epigenome do in affecting gene activity (6 things)?
1) Alter chromatin structure (turn euchromatin into heterochromatin)
2) Recruit histone modifiers
3) Repress transcription
4) Genome-wide pattern established at fertilisation
5) Important for differential gene expression (transcription)
6) Responds to environmental cues (cellular and external)
If all cells have the same genome, why don’t all cells look the same?
It is due to the differential gene expression.
- It differs temporally (time) e.g. development (embryo needs different genes compared to adults) & in response to hormones, infection and other signals
- Spatial differentiation as different tissue and cells express different genes
Failure leads to what conditions?
1) Metabolism
2) Metastasis
3) Congenital disorders
4) Cancer
