Gene Expression Study Guide Flashcards

Monomers of nucleic acids

Nucleotides

Polymers of nucleic acids

DNA and RNA

Sugar in DNA

Deoxyribose

Sugar in RNA

Ribose

Base in RNA instead of thymine

Uracil

Three parts of a DNA nucleotide

Phosphate group, deoxyribose sugar, nitrogenous base

Difference between 5' and 3' ends of DNA

5' has a phosphate group; 3' has a hydroxyl group

DNA strands run in relation to each other

Antiparallel

When DNA replication occurs in the cell cycle

During S phase

Three main steps of DNA replication

Initiation, elongation, termination

Enzyme that unwinds the DNA

Helicase

Enzyme that adds DNA nucleotides

DNA polymerase

Enzyme that creates primers

Primase

Enzyme that joins Okazaki fragments

DNA ligase

Direction DNA is synthesized

5' to 3'

Leading strand

The DNA strand made continuously

Lagging strand

The DNA strand made in short Okazaki fragments

Goal of transcription

To make mRNA from DNA

Where transcription happens

In the nucleus

Enzyme that synthesizes mRNA

RNA polymerase

Three steps of transcription

Initiation, elongation, termination

Intron

Non-coding region removed from mRNA

Exon

Coding region that remains in mRNA

Spliceosomes

Complexes that remove introns and join exons

Goal of translation

To build a protein from mRNA

Where translation happens

In the cytoplasm at ribosomes

Codon

A 3-base mRNA sequence that codes for an amino acid

Anticodon

A 3-base tRNA sequence that pairs with a codon

Function of tRNA

Brings amino acids to the ribosome

Function of rRNA

Makes up part of the ribosome and catalyzes peptide bond formation

Three steps of translation

Initiation, elongation, termination

Convert the DNA sequence TAC to mRNA

AUG

Amino acid coded by AUG

Methionine (Start)