DNA, Gene Expression & Biotechnology – Key Vocabulary 11&12

These vocabulary flashcards cover the major structures of DNA and RNA, the processes of transcription and translation, and foundational biotechnology concepts highlighted in Chapters 11 & 12.

DNA (Deoxyribonucleic Acid)

Double-stranded nucleic acid that stores hereditary information for making every protein in an organism.

RNA (Ribonucleic Acid)

Single-stranded nucleic acid that serves as an intermediary between DNA and protein synthesis.

Nucleotide

The basic unit of nucleic acids, consisting of a phosphate group, a sugar, and a nitrogenous base.

Sugar-Phosphate Backbone

The repeating chain of sugars and phosphates that forms the structural framework of DNA or RNA strands.

Nitrogenous Base

Information-carrying component of a nucleotide; in DNA: adenine, thymine, guanine, cytosine; in RNA uracil replaces thymine.

Adenine (A)

Purine base that pairs with thymine in DNA and with uracil in RNA.

Thymine (T)

Pyrimidine base in DNA that pairs with adenine.

Guanine (G)

Purine base that pairs with cytosine.

Cytosine (C)

Pyrimidine base that pairs with guanine.

Uracil (U)

RNA-only base that pairs with adenine.

Base Pairing Rules

A pairs with T (or U), G pairs with C; ensures accurate replication and repair.

Hydrogen Bond

Weak attraction that holds complementary bases together in the DNA double helix.

Double Helix

Spiral structure of DNA formed by two complementary strands twisting around each other.

Chromosome

Tightly packed DNA molecule associated with histone proteins; humans have 23 pairs.

Histone

Protein spool around which eukaryotic DNA is wrapped and condensed.

Coding Region

Segment of DNA that is transcribed and translated into protein.

Non-coding Region

DNA segment not directly used to code for protein; may have regulatory or unknown functions.

Gene

A specific DNA sequence that codes for a functional protein or RNA product.

Gene Expression

Process by which information from a gene is used to synthesize a functional product (protein); includes transcription and translation.

Genome

Complete set of DNA (all genes and non-coding sequences) in an organism or species.

Messenger RNA (mRNA)

RNA copy of a gene that carries coding information from the nucleus to ribosomes.

RNA Polymerase

Enzyme that binds a promoter and synthesizes RNA during transcription.

Promoter

DNA sequence where RNA polymerase binds to initiate transcription.

Transcription

Nuclear process that builds an mRNA strand complementary to a DNA template.

Cap and Tail

Protective modifications added to eukaryotic mRNA ends before it leaves the nucleus.

Translation

Cytoplasmic process where ribosomes read mRNA and assemble amino acids into a protein.

Ribosome

Cellular structure made of rRNA and proteins; site of protein synthesis.

Transfer RNA (tRNA)

Adaptor RNA that carries specific amino acids and pairs its anticodon with mRNA codons.

Codon

Three-base sequence on mRNA specifying one amino acid or a stop signal.

Start Codon (AUG)

First codon recognized in translation; codes for methionine and initiates protein synthesis.

Stop Codon

mRNA triplet (UAA, UAG, or UGA) that signals termination of translation.

Elongation (Translation)

Stage where ribosome links successive amino acids delivered by tRNAs, extending the polypeptide chain.

Termination (Translation)

Stage when ribosome encounters a stop codon and releases the finished protein.

Amino Acid

Building block of proteins; linked together during translation.

Protein

Polypeptide chain that folds into a functional biomolecule serving structural, enzymatic, regulatory, or other roles.

Biotechnology

Use of organisms, cells, or their molecules to produce practical benefits such as medicines or improved crops.

Genetic Engineering

Direct manipulation of an organism’s DNA by adding, deleting, or transferring genes.

Genetically Modified Organism (GMO)

Organism whose genome has been altered through genetic engineering.

Bt Corn

GMO corn engineered with Bacillus thuringiensis gene to produce insect-killing Bt toxin, reducing pesticide use.

Golden Rice

GMO rice enriched with beta-carotene genes from daffodil and bacteria to combat vitamin A deficiency.