Genetics and Molecular Biology Flashcards
Nucleic Acid
Macromolecules that contain genetic information for protein synthesis.
Nucleic acid structure
1.) Phosphate group- Neg charged oxygen atoms bonded to it
2.) Pentose molecule- Ribose or deoxyribose
3.) Nitrogen base- Can give molecules to carbon, hydrogen, and oxygen
Who discovered nucleic acids?
Friedrich Miescher- From the white blood cells contained in pus he got from used hospital bandages.
Gene expression
Process of using the information in a gene to create a protein inside a cell.
Proteins
Macromolecules that direct all structures and functions of the cell, allowing gene regulation to be tightly controlled.
Steps for gene expression
- Transcription
- mRNA processing
- mRNA export
- Translation
- Protein folding
- Protein translocation
Splicing
Process where introns are removed from the transcript, and the remaining exons are attached back together.
Introns
Non-coding sections of the mRNA
Exons
The remaining coding sections of mRNA
Alternative splicing
mRNA can be sliced in different ways to create different proteins
Stop codon
Signals for translation to stop
Ways that gene expression is regulated
- Transcription factors
- Stability of mRNA
- Alternative splicing
- Post-transcriptional regulation
- Post-translational modifications
Ways to measure gene expression
-Western blot
-Immunofluorescence
- Microarray
- RT-PCR
- In situ hybridization
Insertion mutation
Additional nucleotides are inserted into the DNA
Complementary base pairs
Adenine–Thymine (RNA it is uracil)
Cytosine–Guanine
Frameshift mutation
All of the codons downstream from the mutation are changed
Causes of insertion mutation
- By chance during errors in DNA replication
- By chemicals or radiation
Examples of insertion mutation
- Fragile X syndrome
- Huntington’s disease
-Myotonic dystrophy - Cystic fibrosis
Deletion mutation
When a nucleobase is removed from the DNA sequence
Substitution mutation
When a nucleobase is substituted for another nucleobase.
Duplication mutation
When a section of the DNA sequence is repeated
Causes of deletion mutation
- Translocation
- Unequal chromosome crossovers
Types of deletion mutations
- Point mutation (affects a single nucleobase)
- Frameshift mutation (when one deletion shift all nucleobases in the reading frame)
- Chromosome deletion (An entire missing piece of a chromosome)
Restriction enzymes (endonucleases)
Proteins that recognize and cleave specific DNA sequences. Found only in bacteria.