Mutations Flashcards
What are the steps in determining gene function?
- Find a start codon and a stop codon.
- Find a promoter
- Between the start and stop codon you will find the coding region called a gene.
- Compare 6 frames, the longest one is the most likely protein
- Use database to find similar proteins (BLAST)
- Translate mRNA into proteins
What are domains/motifs?
These are units within the proetin that have their own function.
What is a mutation?
A change in the nucleotide sequence of the DNA.
What is a Point Mutation?
Affects a single nucleotide position. It can be Silent, missense and nonsense.
What is a Missense point mutation?
change of one nucleotide in DNA which results in a change in the mRNA codon to one that encodes a different amino acid and causes a change in the protein produced.
What is a somatic mutation?
Occurs in cells not dedicated to sexual reproduction.
What are germline mutations?
occur in the DNA of an organism’s germline cells, which are the cells responsible for giving rise to gametes (sperm and egg cells) in sexually reproducing organisms.
What is a substitute mutation?
Exchanges one base for another.
What type of mutation is sickle cell?
Missense
What is a nonsense point mutation?
Changes an amino acid codon to stop codon thereby producing an incomplete protein.
What is a silent mutation?
This occurs when a substitution results in an mRNA codon changing to another codon that encodes the same amino acid.
What is a frameshift mutation?
Insertion and deletion involving one or multiple of two base pairs resulting in a change of the reading frame.
What is called when one purine [A or G] or pyrimidine [C or T] is replaced by the other?
Transition
What is it called when a purine is replaced by a pyrimidine or vice-versa?
Transversion
Which R groups are found clustered in the core of the protein?
Non polar (Hydrophic) groups
Which R groups are often found on the surface of the protein?
Polar Groups
Name two amino acids with negative charge?
Aspartic acid and Glutamic acid
What three main categories are R groups broken into?
Non polar
Polar
Charged
Describe the primary strcuture of proteins
A sequence of Amino acids held together by peptide bonds.
Describe the Secondary protein structure
- Formed by hydrogen bonding between peptide bonds.
- Common secondary structures include α-helices and β-sheets.
- R groups do not directly participate in secondary structure formation.
Describe the Tertiary Structure
- Determined by interactions between R groups, including hydrophobic interactions, hydrogen bonds, ionic bonds, and disulfide bonds (cysteine residues).
Describe the Quaternary Structure
- Present in proteins composed of multiple polypeptide chains (subunits).
- Defines the spatial arrangement and interactions between subunits.
- Examples include hemoglobin and collagen.
