APBIO QUIZ

DNA structure and DNA replication (including the enzymes)

Components of DNA: DNA is composed of nucleotides, each containing a phosphate group, a deoxyribose sugar, and nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G). A pairs with T, and C pairs with G.

DNA Replication: Semi-conservative; involves the enzymes:

Helicase: Unwinds the DNA.

Primase: Synthesizes RNA primers.

DNA Polymerase III: Adds nucleotides.

DNA Polymerase I: Replaces RNA primers.

Ligase: Joins Okazaki fragments.

Transcription (including RNA processing and RNA polymerase) and translation including relevant terms (initiation, elongation, termination, codon, anticodon, A site etc)

Transcription: Process of copying a gene’s DNA into RNA.

Initiation: RNA polymerase binds to the promoter.

Elongation: RNA polymerase adds nucleotides.

Termination: RNA polymerase reaches a terminator and releases the transcript.

RNA Processing: In eukaryotes, includes:

5' capping: Adds a protective cap.

Polyadenylation: Adds a poly-A tail.

Splicing: Removes introns and joins exons to form mature mRNA.

DNA structure and DNA replication (including the enzymes)

Components of DNA: DNA is composed of nucleotides, each containing a phosphate group, a deoxyribose sugar, and nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G). A pairs with T, and C pairs with G.

DNA Replication: Semi-conservative; involves the enzymes:

Helicase: Unwinds the DNA.

Primase: Synthesizes RNA primers.

DNA Polymerase III: Adds nucleotides.

DNA Polymerase I: Replaces RNA primers.

Ligase: Joins Okazaki fragments.

Transcription (including RNA processing and RNA polymerase) and translation including relevant terms (initiation, elongation, termination, codon, anticodon, A site etc)

Transcription: Process of copying a gene’s DNA into RNA.

Initiation: RNA polymerase binds to the promoter.

Elongation: RNA polymerase adds nucleotides.

Termination: RNA polymerase reaches a terminator and releases the transcript.

RNA Processing: In eukaryotes, includes:

5' capping: Adds a protective cap.

Polyadenylation: Adds a poly-A tail.

Splicing: Removes introns and joins exons to form mature mRNA.

Gene Expression ( activators, enhancers, methyl and acetyl groups, RNAi, epigenetics)

Gene Expression Regulation:

Activators: Proteins that bind to enhancers to increase transcription.

Enhancers: DNA sequences that enhance transcription when bound by activators.

Methylation: Adding methyl groups to DNA usually represses gene expression.

Acetylation: Adding acetyl groups to histones promotes gene expression by loosening DNA.

RNAi: Small RNA molecules that inhibit mRNA translation or cause mRNA degradation.

Mutations (different types that affect protein synthesis), viruses (RNA, DNA and retroviruses) and how they reproduce and bacterial methods of getting new DNA

Mutations:

Point mutations: A single nucleotide change.

Frameshift mutations: Insertion or deletion of nucleotides that shift the reading frame.

Silent mutations: No change in the amino acid.

Missense mutations: Change in one amino acid.

Nonsense mutations: A stop codon is created, truncating the protein.

Viruses:

DNA viruses: Replicate their DNA in the host.

RNA viruses: Directly replicate RNA in the host.

Retroviruses: RNA viruses that convert RNA to DNA and integrate it into the host genome (e.g., HIV).

Bacterial DNA Acquisition:

Transformation: Uptake of free DNA.

Conjugation: Transfer of DNA between bacteria via direct contact.

Transduction: Transfer of bacterial DNA via bacteriophages.

Proteins Folding, bonds and polarity

Protein Folding: Proteins fold into specific three-dimensional shapes driven by interactions between amino acids.

Hydrophobic interactions: Nonpolar amino acids cluster inside the protein.

Hydrogen bonds: Between polar amino acids.

Disulfide bridges: Covalent bonds between cysteine residues.

Ionic bonds: Between oppositely charged amino acids.

Mutations:

Point mutations: A single nucleotide change.

Frameshift mutations: Insertion or deletion of nucleotides.

Silent mutations: No change in protein.

Missense mutations: A single amino acid is changed.

Nonsense mutations: A stop codon is created.

Viruses:

DNA viruses: Replicate their DNA in the host.

RNA viruses: Replicate RNA directly.

Retroviruses: Convert RNA to DNA and integrate it into the host genome.

Bacterial DNA Acquisition:

Transformation: Uptake of free DNA.

Conjugation: Transfer of DNA via direct contact.

Transduction: DNA transfer by bacteriophages.

What happens during translation, including initiation, elongation, and termination, and what are codons and anticodons?

Translation: Converts mRNA into a polypeptide.

Initiation: The small ribosomal subunit binds to mRNA, and the start codon (AUG) is recognized.

Elongation: tRNA molecules bring amino acids, matching anticodons to mRNA codons.

Termination: A stop codon signals the end of translation.

Codon: A sequence of three mRNA nucleotides that code for an amino acid.

Anticodon: A complementary sequence on tRNA that pairs with the codon.