L1 - Introduction to Molecular Biology – Vocabulary Review

30 key vocabulary flashcards covering fundamental terms introduced in the opening lecture on molecular biology, DNA structure, and gene expression.

Molecular Biology

Discipline focused on the structure, function and expression of DNA, RNA and proteins in living cells.

DNA (Deoxyribonucleic Acid)

Long, double-helical polymer that stores hereditary genetic information in all known forms of life.

RNA (Ribonucleic Acid)

Single-stranded nucleic acid that serves as an information intermediate and functional molecule in gene expression.

Central Dogma

Concept that genetic information flows from DNA → RNA → Protein, with DNA also replicating itself.

Replication

Process by which DNA is copied to produce identical DNA molecules.

Transcription

Synthesis of RNA from a DNA template inside the nucleus.

Translation

Cytoplasmic process that decodes mRNA to build a specific protein.

Nucleotide

Base + sugar + one or more phosphate groups; building block of nucleic acids and cellular energy currency.

Nucleoside

Base attached to a sugar but lacking phosphate groups.

Purine

Two-ring nitrogenous base category that includes adenine and guanine.

Pyrimidine

Single six-membered ring base category that includes cytosine, thymine and uracil.

Adenine (A)

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

Guanine (G)

Purine base that pairs with cytosine in both DNA and RNA.

Cytosine (C)

Pyrimidine base that pairs with guanine in DNA and RNA.

Thymine (T)

DNA-specific pyrimidine base that pairs with adenine.

Uracil (U)

RNA-specific pyrimidine base that pairs with adenine.

Ribose

Five-carbon sugar found in RNA nucleotides, possessing a 2′-hydroxyl group.

Deoxyribose

Five-carbon sugar in DNA nucleotides lacking the 2′-hydroxyl group.

Phosphodiester Bond

Covalent linkage connecting the 3′-OH of one nucleotide to the 5′-phosphate of the next.

5′ → 3′ Polarity

Directional orientation of nucleic acid strands defined by free 5′-phosphate and free 3′-hydroxyl ends.

Double Helix

Right-handed, antiparallel arrangement of two complementary DNA strands.

Photo 51

Rosalind Franklin’s X-ray diffraction image that revealed DNA’s helical structure.

X-ray Crystallography

Technique using X-ray diffraction by crystals to determine molecular structures such as DNA.

ATP (Adenosine Triphosphate)

High-energy nucleotide that acts as the primary energy currency of the cell.

Acetyl CoA

Coenzyme A derivative carrying activated acetate for metabolic reactions.

cAMP (Cyclic AMP)

Cyclic nucleotide functioning as an intracellular signaling molecule.

Polymerization (of nucleic acids)

Enzymatic joining of nucleotides into linear DNA or RNA chains.

Eukaryotic Cell

Cell type with a membrane-bound nucleus housing DNA, and cytoplasm where translation occurs.

Nucleus

Organelle where eukaryotic DNA replication and transcription take place.

Cytoplasm

Cellular compartment where ribosomes translate mRNA into protein.