Molecular Biology Review

Vocabulary flashcards covering key concepts in molecular biology, including DNA, RNA, protein synthesis, and PCR.

Nucleotide

Has a phosphate group, a ribose sugar, and a nitrogenous base.

Nucleoside

Does not have a phosphate group but has a ribose sugar and a nitrogenous base.

RNA Sugar

Has a ribose sugar.

DNA Sugar

Has a deoxyribose sugar (missing an OH).

Pyrimidine

A smaller molecule, includes Cytosine, Uracil, and Thymine (CUT).

Uracil vs Thymine Location

Uracil is found in RNA, Thymine in DNA; they do not appear in the same sequence.

Purine

A larger molecule, includes Adenine (A) and Guanine (G).

ADP

Adenosine Diphosphate; contains two phosphate groups.

ATP

Adenosine Triphosphate; contains three phosphate groups and is responsible for energy production.

Energy Production in ATP

Occurs when a phosphate group is cleaved off (ATP to ADP), releasing energy from the broken phosphodiester bond.

Phosphate Backbone Charge

Gives DNA a negative charge, crucial for cellular function.

DNA Strands Direction

Original strand goes from 3' to 5', complementary strand goes from 5' to 3' (antiparallel).

Central Dogma

DNA undergoes transcription into RNA, then RNA undergoes translation to ribosome for protein synthesis.

DNA Replication

Parent DNA strands separate and are complemented by new daughter DNA strands.

Base Pairing in DNA

A pairs with T, G pairs with C.

Base Pairing in RNA

A pairs with U, G pairs with C.

RNA Structure

Single-stranded and shorter than DNA, not a double helix.

Types of RNA

Ribosomal RNA (rRNA), Messenger RNA (mRNA), and Transfer RNA (tRNA).

Ribosomal RNA (rRNA)

Provides the site within the ribosome for polypeptide binding during protein synthesis.

Messenger RNA (mRNA)

Carries information from the nucleus to the ribosome.

Transfer RNA (tRNA)

Brings specific amino acids to the ribosomes for protein synthesis, contains an anticodon.

Transcription

The process of converting DNA to RNA. Involves replacing thymine (T) with uracil (U).

Codon

A sequence of three nucleotides that codes for an amino acid.

Genetic Code Chart

Used to look up which codon corresponds to which amino acid.

Start and Stop Codons

Indicate where to start and stop protein synthesis. Methionine is a common start codon.

Amino Acids and Proteins

Proteins are made of many amino acids linked together.

Codon and Anticodon

Complementary sequences on mRNA and tRNA respectively. The anticodon on tRNA is crucial for bringing the correct amino acid.

Protein Synthesis Stages

Initiation (start), Elongation (building the protein), and Termination (stop).

Ribosome Structure

Composed of a small and a large ribosomal subunit. The tRNA is located inside the ribosome.

Eukaryotic vs Bacterial Ribosomes

Eukaryotic ribosomes are 80S, while bacterial ribosomes are 70S. Antibiotics often target the bacterial 70S ribosome.

Mutation

A change in the nucleotide sequence of DNA.

Point Mutation

Substitution of a single nucleotide.

Deletion Mutation

One or more nucleotides are deleted.

Insertion Mutation

One or more nucleotides are inserted.

Silent Mutation

A mutation that does not change the amino acid sequence.

Recombinant DNA

Technique of cleaving human DNA and inserting it into another DNA (e.g., bacterial plasmid) for cloning or protein production.

PCR (Polymerase Chain Reaction)

A method to amplify DNA, creating many copies from a small sample.

PCR Process

Involves separating DNA strands, adding primers, and using a thermal cycler to replicate the DNA sequence.

Gel Electrophoresis

A technique used to separate DNA fragments based on size and charge, often used in conjunction with PCR.