Unit 6 Gene Expression and Regulation - Active Reading Guide

A comprehensive set of flashcards based on key concepts and terms related to nucleic acids, DNA and RNA structure and function, gene expression, replication, and other related topics.

Nucleic acids

Biomolecules, including DNA and RNA, that encode genetic information through their nucleotide sequence.

DNA

Deoxyribonucleic acid, which acts as the long-term storage of genetic information and provides instructions for an organism's development, survival, and reproduction.

RNA

Ribonucleic acid, primarily serving as a messenger that carries genetic instructions from DNA to ribosomes for protein synthesis.

Nucleotide

The basic building block of nucleic acids, composed of a phosphate group, a sugar, and a nitrogenous base.

DNA vs RNA

DNA contains deoxyribose and thymine, is double-stranded (helix), while RNA contains ribose and uracil, is usually single-stranded.

Purines

A type of nucleotide with a double-ring structure; includes adenine and guanine.

Pyrimidines

A type of nucleotide with a single-ring structure; includes cytosine, thymine (DNA only), and uracil (RNA only).

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process where ribosomes read the mRNA sequence to assemble amino acids into a polypeptide.

Gene regulation

The process of turning genes on or off to ensure the production of proteins at the right times.

Replication fork

The Y-shaped region where the DNA double helix is unwound and new strands are being synthesized.

Semiconservative replication

The process by which DNA replicates, yielding one old strand and one new strand in each new DNA molecule.

DNA polymerase

An enzyme that synthesizes new DNA strands and has proofreading capabilities to ensure accuracy.

Leading strand

The DNA strand synthesized continuously toward the replication fork in the 5'-3' direction.

Lagging strand

The DNA strand synthesized in short fragments called Okazaki fragments, discontinuously away from the replication fork.

Okazaki fragments

Short segments of DNA synthesized on the lagging strand during replication.

Proofreading

The process by which DNA polymerase checks and corrects each newly added nucleotide against the template.

Plasmid

A small, extra-chromosomal circular DNA molecule often found in bacteria that carries additional genes.

Central dogma

The flow of genetic information from DNA to RNA to protein.

Mutations

Changes in DNA sequence that may be harmful, neutral, or beneficial, contributing to genetic variation.

Gene

A segment of DNA that codes for a particular protein.

Histones

Proteins that help package DNA into structural units called nucleosomes, rich in positively charged amino acids.

Base pairing

The specific pairing of nitrogenous bases in DNA (adenine with thymine, guanine with cytosine) that ensures accurate replication.

Environmental damage

Factors such as UV radiation and chemicals that can cause mutations in DNA.

Cell division

The process by which cells replicate, involving binary fission in prokaryotes and mitosis or meiosis in eukaryotes.