Lecture 1 Flashcards
(23 cards)
What is gene expression?
The process by which information from a gene is used in the synthesis of a functional gene product (protein OR ncRNA)
How many protein coding genes are there in humans?
Approximately 20,000 protein coding genes
What initiates transcription?
Transcription factors bind to the TATA box and other regions of the promoter
What is the role of RNA polymerase II in transcription?
RNA pol II binds, forming a transcriptional initiation complex and starts mRNA synthesis without the need of a primer
What does the coding strand refer to?
The strand of DNA that is used as a template for mRNA synthesis
List some functions of proteins synthesized from gene expression.
- Structural (e.g., Collagen)
- Regulatory (e.g., Insulin)
- Contractile (e.g., Actin, myosin)
- Transport (e.g., Haemoglobin)
- Storage (e.g., Egg white)
- Protective (e.g., Antibodies)
- Catalytic (e.g., Amylase)
- Toxic (e.g., Botulinum toxin)
What is ncRNA?
Non-coding RNA that has regulatory functions to regulate gene expression
What is an example of a regulatory function of tRNA?
Adaptor protein between mRNA and protein
True or False: Abnormal gene expression can lead to genetic disorders.
True
Name three common genetic disorders.
- Cystic fibrosis
- Huntington’s disease
- Down syndrome
What defines a gene?
A sequence of DNA that specifies the production of a functional product
What is the human genome?
All the DNA present in a cell
How many chromosomes does human DNA typically contain?
46 chromosomes (23 pairs)
What is the difference between somatic cells and gametes?
- Somatic cells – diploid (2n)
- Gametes – haploid (n)
What percentage of human DNA is protein coding?
Approximately 1 - 1.5%
What is a promoter?
Regulatory DNA segment recognised by RNA polymerase to initiate transcription
What are 5’ and 3’ UTRs?
Untranslated regions that contain regulatory elements influencing gene expression
What is the function of the 5’ G cap?
Prevents mRNA degradation and regulates translation
Fill in the blank: Enhancers bind proteins that ______ the rate of transcription.
[increase]
What are transposable elements (TEs)?
DNA sequences that can move around in the genome, making up about 45% of our genome
What can happen if a transposable element jumps into a gene?
It can cause abnormal expression of that gene
List some examples of regulatory RNA types.
- miRNA (micro RNA)
- siRNA (small interfering RNA)
- lncRNA (long non-coding RNA)
- snoRNA (small nucleolar RNA)
What do enhancers and silencers have in common?
They both can influence the rate of transcription but in opposite ways
