Gene Expression Exam Review

These flashcards cover fundamental terms and concepts related to gene expression, including DNA structure, transcription, translation, mutations, and their implications for phenotypes and metabolic pathways.

DNA

Double-stranded molecule carrying genetic information.

Nucleotide

Phosphate + sugar + base.

Base pairing

A–T and C–G.

Triplet

Three DNA bases coding for one amino acid.

Gene

DNA sequence that codes for a polypeptide.

Allele

Different version of a gene.

Chromosome

DNA molecule containing many genes.

Genome

All the DNA in an organism.

Histones

Proteins that DNA wraps around.

Transcription

Making an mRNA copy of DNA.

mRNA

Messenger RNA carrying instructions to ribosome.

RNA polymerase

Enzyme building mRNA.

Promoter region

Where transcription starts.

Template strand

DNA strand used to build mRNA.

Coding strand

Matches mRNA (except U replaces T).

Codon

Three mRNA bases coding for an amino acid.

tRNA

Transfers amino acids to ribosome.

Anticodon

Three tRNA bases complementary to mRNA codon.

Polypeptide

Chain of amino acids.

Protein

Folded polypeptide.

Mutation

Permanent change in DNA base sequence.

Point mutation

One base change.

Silent mutation

No amino acid change.

Missense mutation

Amino acid change.

Nonsense mutation

Stop codon created, leading to short protein.

Frameshift mutation

Insertion/deletion shifting reading frame.

Metabolic pathway

Series of linked chemical reactions in a cell, catalysed by enzymes

Phenotype

Trait determined by protein action.

Inducible expression

Gene switched on/off by environment.

Polygenic trait

Controlled by many genes.

Regulatory gene

Codes for a protein controlling other genes.

Ribosome

Reads mRNA.

Enzyme

Protein catalyzing reactions.

Substrate

Molecule enzyme acts on.