Final Review

To convert mRNA sequence into an amino acid sequence using ribosomes, tRNAs, and translation factors.

In the cytoplasm, on free ribosomes or on ER-bound ribosomes.

A site (Aminoacyl), P site (Peptidyl), and E site (Exit).

It ensures correct codon-anticodon pairing.

Binding of the 30S subunit to mRNA and initiator tRNA carrying fMet.

A sequence in prokaryotic mRNA that positions the ribosome at the start codon.

It binds to the 5′ cap of mRNA to facilitate translation.

It includes the 40S subunit and initiator tRNA for mRNA scanning.

It guides aminoacyl-tRNA into the A site.

The peptidyl transferase activity of rRNA.

UAA, UAG, UGA.

They bind stop codons and release the polypeptide.

Clusters of ribosomes translating the same mRNA simultaneously.

Prokaryotic: 70S; eukaryotic: 80S.

An inducible operon regulating lactose metabolism in E. coli.

Allolactose inactivates the repressor, allowing transcription.

High glucose lowers cAMP, reducing lac operon transcription.

A repressible operon controlling tryptophan synthesis.

Tryptophan activates the repressor to stop transcription.

A mechanism regulating transcription based on tryptophan levels.

To produce correct proteins at the right time and conserve energy.

Transcriptional, post-transcriptional, translational, post-translational.

Altering DNA accessibility for transcription.

Enhancers increase transcription, silencers decrease it.

Heritable changes in expression without altering DNA sequence.

Assist proper protein folding.

Phosphorylation, glycosylation, acetylation, methylation, ubiquitination, disulfide bonds.

Direct proteins to specific locations like the ER or mitochondria.

Stalled ribosome rescue, tRNA proofreading, mRNA surveillance.

Leader peptide is translated quickly, forming a terminator hairpin that stops transcription.

Ribosome stalls; an antiterminator hairpin forms; transcription continues.

Coupled transcription and translation.

Proteins that bind the operator to block transcription.

Proteins that increase transcription by helping RNA polymerase bind.

Molecules that inactivate repressors.

Molecules that activate repressors.

Chromatin structure, enhancers/silencers, many transcription factors.

Euchromatin and heterochromatin.

Increases transcription by loosening DNA-histone interaction.

Condenses chromatin and decreases transcription.

A modification that usually decreases transcription.

Move or remove nucleosomes using ATP.

TATA box, Inr, DPE, BRE—determines transcription start.

DNA sequences that increase transcription.

DNA sequences that decrease transcription.

Proteins required for Pol II transcription.

Specific factors regulate particular genes; general are required for all Pol II genes.

Changes in expression independent of DNA sequence.

Producing multiple proteins from one gene.

Poly-A tail length affects degradation.

miRNA or siRNA repress or degrade mRNA.

An example of translational control by iron levels.

DNA replication is semi-conservative.

Binds origins throughout the cell cycle.

Each origin fires once per cycle.

Unwinds DNA ahead of replication fork.

Synthesizes RNA primer and initial DNA.

Seals nicks between Okazaki fragments.

TTAGGG repeats protecting chromosome ends.

Reverse transcriptase extending telomeres.

Lagging strand cannot fill final primer gap.

Catalytic protein of telomerase.

RNA template of telomerase.

Germ cells, embryonic stem cells, cancer cells.

It is inactive, causing aging.

Ensures replication occurs once per cycle.

CDK/DDK activation and CMG helicase formation.

Inhibits Cdt1 to prevent relicensing.

Replication errors or chemical changes.

Loss of A or G.

C→U or 5-mC→T conversion.

UV-induced lesions.

Single nucleotide changes.

Changes one amino acid.

Fixes replication errors.

Glycosylase removes damaged base → repair.

Removes bulky lesions.

Error-prone double-strand break repair.

Accurate double-strand break repair.

A transforming principle converts R cells to S.

DNA is the hereditary molecule.

DNA enters cells, not protein.

Base, deoxyribose, phosphate.

A=T, G=C.

Double helix.

5'→3' and 3'→5'.

Hydrogen bonds and base stacking.

Major = wide; minor = narrow.

Proteins read DNA there.

Three DNA forms.

Right-handed.

Compressed and dehydrated.

A hereditary unit encoding RNA or protein.

Genes producing mRNA.

Genes producing functional RNA.

Gene = sequence; allele = variant.

Griffith.

DNA is the transforming principle.

Synthesizes RNA from DNA.

Initiation, elongation, termination.

RNA has ribose and U instead of T.

A–U, T–A, G–C, C–G.

Core enzyme + sigma factor.

-35 and -10 boxes.

TFIID binding site.

Directs polymerase to promoters.

Phosphorylation triggers promoter escape.

Rho-independent and Rho-dependent.

Moves along RNA and releases it.

AAUAAA.

Adds ~200 adenines to mRNA.

RNA destabilizes; torpedo model applies.

Removal of γ-phosphate.

m⁷G cap.

Protection, ribosome binding, export.

Recognition of AAUAAA.

Binds AAUAAA.

Stabilize mRNA and enhance translation.

Prokaryotes: 1 polymerase; eukaryotes: Pol I/II/III.

Removes introns.

GU, branch A, polypyrimidine tract, AG.

Spliceosome components.

Lariat formation & exon ligation.

Exon skipping, mutually exclusive exons, alt 5'/3' sites, etc.

Links codons to amino acids.

Cloverleaf.

CCA end attaching the amino acid.

Charge tRNAs with amino acids.

Catalyzes peptide bonds.

50S (23S+5S) + 30S (16S).

Aligns mRNA with ribosome.

α-carbon, NH₂, COOH, H, R group.

Protein amino acids are L-isomers.

Glycine.

Hydrophobic or hydrophilic.

Glycine, alanine, valine.

Found on protein surfaces.

Peptide bond.

Condensation.

Amino acid sequence.

Hydrogen bonds.

α-helix and β-sheet.

3D folding of one polypeptide.

Multiple polypeptide subunits.

Three-base mRNA sequence.

AUG.

Flexible third-base pairing.

Four-stranded recombination intermediate.

Spo11.

CO and NCO.

Hold sister chromatids.

Chromosomes unreplicated.

DNA replication.

Stabilize chromosome ends.

Shared evolutionary ancestry.

Reads codons, carries amino acids.

Hydrophobic, H-bonds, ionic, disulfide, van der Waals.

Links amino acids.

Defines amino acid properties.

Higher chromatin condensation requiring H1.

Aligns homologs in meiosis.

Creates variation.

Produces haploid gametes, not identical cells.

Two.

Prophase I.

Exchange between homologs.

Random alignment of homolog pairs.

Number of possible gametes.

Random gamete fusion.

Chromatin, centromeres, telomeres, origins.

Single chromatids.

Ensures correct segregation.

Alleles separate in gamete formation.

Single-trait inheritance.

3:1.

Two-trait inheritance.

9:3:3:1.

Genotype = genes; phenotype = traits.

One allele fully masks another.

Heterozygote intermediate.

Both alleles expressed.

One gene affects multiple traits.

One gene masks another.

Alleleenotype frequencies remain constant.

Large population, random mating, no mutation/migration/selection.

Remain constant in equilibrium.

Increases beneficial alleles.

Fixation, maintenance, loss, drift.

Single-gene traits.

Independent assortment.

Create new alleles.

Baseline to detect evolution.

Hardy-Weinberg equation.

Determining gene order and distance.

Linked genes separated by crossing-over.

Synapsis and DSB formation.

% recombinants.

Genes are close.

Heterozygote × recessive.

Determines gene order and distances.

One crossover reduces nearby crossover chance.

Mapping disease genes.

Creates new allele combinations.

Uses ddNTPs to terminate strands.

High throughput, accuracy, low cost.

Lower accuracy historically.

≈1 per 100,000 bp.

≈3.2 billion bp, 24 chromosome types.

Determine inheritance and linkage.

Genes far apart.

Reveal middle gene.

Single-base polymorphisms used in mapping.

Assembly into contigs/scaffolds.

50% due to multiple crossovers.

~1.5%.

~98.5%.

Noncoding gene regions removed in splicing.

Regulatory, structural, evolutionary roles.

Movable DNA sequences (~45%).

Long/short interspersed nuclear elements.

Negative regulators of growth.

Single nucleotide change.

Amino acid substitution.

Leukemia-associated translocation.

Targets non-reproductive cells.

Targets gametes/embryos; heritable.

Safety, access, enhancement vs. treatment.

Improve yield, resistance, nutrition.

Roundup Ready.

Expresses Bacillus thuringiensis toxin.

Produces β-carotene.

Gene flow, superweeds, biodiversity effects.

Law preventing genetic discrimination.

Heritable effects, unknown risks.

Case upholding forced sterilization.

Human rights abuses, distrust, ethical debates.

Major genomic component, includes transposons.

Regulate gene expression and chromatin.

Alters splicing; can cause disease.

Cause disorders like Huntington’s and Fragile X.

Producing pharmaceuticals in GM plants/animals.

Proto-oncogenes and tumor suppressors.

Disorders like Down syndrome.

Delivery, immune response, temporary expression.