Gene expression Flashcards
Gene expression
the process by which the instructions in our DNA are converted into a functional product (protein).
Nucleic Acids
The two nucleic acids are DNA and RNA . They are polymers (giant molecules) made up of units called nucleotides.
Nucleotides
Nucleotides are made up of a nitrogenous base, a 5-carbon sugar and a phosphate group.
RNA structure
A single strand of nucleotides (A, G, U, C). Relatively short and transient molecule
Role of DNA
The instructions for cell structure and function
Coding strand
The side of the DNA that is identical to the mRNA strand (bar U and T) and is not involved in transcription
Template strand
The side of DNA molecule which is copied during protein synthesis
Triplet
A group of 3 bases coding for a specific amino acid in the DNA
Codon
A group of 3 bases in mRNA coding for a specific amino acid
Anti-codon
3 bases in tRNA coding complementary to the codon in mRNA
Proteins
A folded polypeptide chain
mRNA
Messenger RNA carries the genetic.code from the nucleus to the ribosomes
tRNA
Transfer RNAs carry amino acids to the ribosome to make a protein
Translation
Changing an mRNA into a polypeptide chain
Transcription
Copying a gene from DNA into mRNA
Deletion
A form of mutation where one or more of the DNA bases is removed from the DNA chain and lost forever
Insertion
A form of DNA mutation where one or more bases is added (inserted) into DNA chain, changing the genetic coding of the chain dramatically
Substitution
A form of DNA mutation involving the replacement or substitution of a single nucleotide base with another
Reading Frame-Shift
A type of gene mutation wherein the addition or deletion of base(s) causes a shift in the reading frame of the codons downstream of the mutation.
metabolic pathway
a series of enzyme controlled reactions, where the product of one reaction is the reactant in the next reaction.
substrate
the molecule that an enzyme acts on. it has a specific shape that fits the enzyme
enzyme
are biological catalysts that lower the activation energy needed to start a reaction by providing an alternative reaction pathway
metabolism
sum of all the enzyme-controlled reactions that occur in a cell
how mutation works in a gene and how does it effect enzymes
If only gene A is mutated, this means enzyme A is not functional/not made. If enzyme A does not work, it means that the substrate will not be converted to the end product and will accumulate,
Structure of a protein(not.p.p.chain)
primary, secondary, tertiary and quaternary
Same-sense
base subition that doesnt result in an change in the animo acid sequence/which was coded for and has no visible nor harmful or beneficial effects
Mis-sense
a mutation causes a change in the sequence of amino acids and can cause severe changes to protein and could be non-functional and harmful
Non-sense
is when a mutation causes a change in DNA coding for a stop codon early than expected which generally leads to a non-functional protein
DNA structure
DNA is double stranded molecule made of deoxyribose sugar, a base (c,t,a,g) and a phosphate group. It is a double helix
