19.1.1119 · Genetic Technology
Bioinformatics — Cambridge AS & A Level Biology 9700 Revision Notes & Topical Questions
5 min read 10 parts Lesson 12 of 20 1 quiz
Lesson summary
19.1.11 Bioinformatics — CAMBRIDGE AS & A LEVEL BIOLOGY 9700 — REVISION NOTES notes: Describe how bioinformatics is used to store, search and analyse biological data.Techniques such as microarrays and gene sequencing generate enormous quantities of data.The data include genome se…
- Gene finding
- Protein prediction
- Tracking disease
- Agriculture
- Conservation
- Complementary
Part 1 of 8What bioinformatics is
Techniques such as microarrays and gene sequencing generate enormous quantities of data.
The data include genome sequences, the timing of gene expression and the amino acid sequence and function of proteins.
Bioinformatics
- Bioinformatics the analysis of this data.
- It is an interdisciplinary science combining biology with computer technology and statistics.
- Biological data are collected, organised, manipulated, analysed and stored.
Part 2 of 8Databases and software
Databases and software
Large online databases hold information from gene sequences to protein amino acid sequences and can analyse selected data.
Software developers are important because the data must be accessed and searched.
Examples of databases and tools:
- European Molecular Biology Laboratory Nucleotide sequence database.
- ArrayExpress — microarray data on levels and types of mRNA expressed in different cells.
- Protein Data Bank in Europe — protein sequence and structure searches.
- BLAST (Basic Local Alignment Search Tool) — finds similarities between a studied sequence and sequences in the database.
Part 3 of 8Using sequence data
1Gene finding
- Gene finding programs locate start and stop codons, promoters and exon-intron boundaries.
2Protein prediction
- Protein prediction the amino acid sequence is deduced from DNA and software predicts structure and active sites.
3
A match to a gene of known function suggests a similar role for an unknown gene.
Part 4 of 8Comparing genomes
1
Once a genome is sequenced, it can be compared with other organisms' genomes in the databases.
2
The degree of similarity shows how closely related organisms are.
3
The more similar the sequences, the more recently the species diverged.
4
It helps identify organisms that could be models for humans, e.g. the fruit fly Drosophila.
Part 5 of 8Fields of study
| Field | What it studies |
|---|---|
| Genomics | The complete DNA sequence of organisms and genome comparisons |
| Transcriptomics | All mRNAs expressed in a cell |
| Proteomics | All the proteins of a cell, their structures and interactions |
| Phylogenetics | Evolutionary relationships from sequence differences |
Part 6 of 8Applications
Medicine
- Medicine finding disease-causing alleles and designing drugs that fit target proteins.
Tracking disease
- Tracking disease sequencing pathogens to see how they mutate and spread and to design vaccines.
Agriculture
- Agriculture locating genes for yield, disease resistance and drought tolerance.
Conservation
- Conservation assessing the genetic diversity of endangered species.
Forensics
- Forensics matching DNA profiles in databases.
Part 7 of 8Limits and issues
Limits and issues
Predicting protein function from sequence alone is uncertain.
Large data sets raise problems of storage, quality and analysis.
Ethical concerns include genetic privacy and use of genetic information by insurers or employers.
Part 8 of 8More from the specification
More from the specification
Restriction Endonucleases in Gene Isolation
- Restriction endonucleases are bacterial enzymes that recognize specific symmetrical palindromic recognition sequences, cutting the sugar-phosphate backbone to cleave out a desired gene and produce sticky ends.
Reverse Transcriptase in cDNA Synthesis
- Genetic engineering employs reverse transcriptase to transcribe isolated mature eukaryotic mRNA into a single strand of complementary DNA (cDNA), effectively excluding non-coding intron regions.
DNA Polymerase in Recombinant Synthesis
- Heat-stable Taq DNA polymerase synthesizes a complementary second strand to create double-stranded DNA fragments and amplifies target sequences during the polymerase chain reaction.
Bioinformatics in Genomic Analysis
- Bioinformatics encompasses computational tools, algorithms,
- and biological databases that allow scientists to catalogue, align,
- and compare DNA and amino acid sequences from diverse organisms.
Recombinant
- Offspring with a new combination of characteristics formed by crossing over.
Electrophoresis
- Separation of molecules by size in an electric field
Genetic engineering
- Deliberate modification of a characteristic of an organism by transferring genes.
Restriction endonuclease
- Enzyme cutting DNA at a specific recognition sequence.
Reverse transcriptase
- Enzyme synthesising DNA from an RNA template
Marker gene
- Gene coding for a detectable substance, used to identify modified cells.
Restriction enzyme
- An enzyme that cuts DNA at specific sequences, leaving sticky ends.
Genetically modified
- Having had genes from another organism inserted.
Bacteria
- Single-celled microorganisms, much smaller than plant or animal cells.
Enzyme
- A protein that functions as a biological catalyst.
Complementary
- Having a matching shape.
Plasmids
- Convenient vectors
Plasmid
- A small ring of DNA in a bacterium carrying extra genes.
Key terms
| Term | Meaning |
|---|---|
| Bioinformatics | Analysis of biological data using computers and statistics. |
| BLAST | Basic Local Alignment Search Tool for finding similar sequences. |
| Database | Large organised store of biological data. |
| Genomics | Study of complete genome sequences. |
| Proteomics | Study of all the proteins of a cell. |
| Model organism | Organism used in research as a model for another, e.g. Drosophila. |
Avoid these mistakes
1
Saying bioinformatics is only computing — it combines biology, computing and statistics.
2
Saying a sequence match proves function — it only suggests a similar role.
3
Confusing BLAST with a database — it is a search tool for finding similar sequences.
4
Forgetting that more similar sequences mean more closely related organisms.
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