Genetic Expression

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Mutation

permanent change in a cell's DNA, ranging from changes in a single base pair to deletions of large sections of chromosomes

Mutagen

A chemical or physical agent that interacts with DNA and causes a mutation.

Anticodon

group of three bases on a tRNA molecule that are complementary to an mRNA codon

Codon

A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid

deletion mutation

a change in the base sequence of a gene that results from the loss of one or more base pairs in the DNA

substitution mutation

Mutation in which a single base is replaced, potentially altering the gene product.

Enzyme

Biological catalysts that speed up the rate of chemical reactions in biological processes by lowering the activation energy. Enzymes are proteins which are coded for by genes.

frameshift mutation

mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide

Gene

A segment of DNA on a chromosome that codes for a specific trait

gene expression

The process by which information encoded in DNA directs the synthesis of proteins

metabolic pathway

A series of enzyme-controlled reactions, where the product of one reaction becomes the substrate of the next

missense mutation

A base-pair substitution that results in a codon that codes for a different amino acid.

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

Non-sense mutation

a stop codon is added instead of amino acid

Phenotype

An organism's physical appearance, or visible traits.

Redundancy of the Code

There are more possible combinations of codons than amino acids, so some repeat

same sense mutation

Base substitution mutation that changes one codon into a different codon that codes for the SAME amino acid

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

Translation

(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

Purpose of template strand

To provide a template for mRNA bases to join to, to create a single helix mRNA strand which is genetically similar to the coding strand, except the u and t are swapped

Environmental factors

A feature in the environment which can change the phenotype of an organsim while the genotype remains the same.

Why is the DNA stored in the nucleus?

To protect it from chemical degradation in the cytoplasm

What is the promoter region

where RNA polymerase binds to initiate transcription

What is the terminator region

where RNA polymerase stops to indicate that the mRNA strand is complete

What are ribosomes made of?

rRNA and proteins

What is the triplet code?

The standard version of the genetic code, in which a sequence of 3 nucleotides in a DNA/RNA molecule codes for a specific amino acid in protein synthesis.

What is DNA?

a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses

What are triplets used for

To create the codons on the mRNA strand