Lecture 10 Anabolism and Genetics Fall 2026

What is metabolism?

All chemical reactions in a cell.

What is catabolism?

Breakdown of complex molecules into simpler ones, releasing energy.

What is anabolism?

Synthesis of complex molecules from simpler ones, requiring energy input.

What is the Calvin cycle?

An anabolic pathway that fixes CO2 into carbohydrates.

Which photosynthesis reactions include the Calvin cycle?

The dark reactions.

Why is the Calvin cycle crucial to life?

It produces organic matter used by heterotrophs.

What two inputs power biosynthesis in the Calvin cycle?

ATP and NADPH.

What enzyme catalyzes the first key Calvin cycle reaction?

RuBisCo.

What does RuBisCo do in the Calvin cycle?

Adds CO2 to ribulose-1,5-bisphosphate.

What does the first key Calvin cycle reaction produce?

Two molecules of 3-phosphoglycerate.

What are carboxysomes described as concentrating?

RuBisCo and its CO2 substrate.

What is gluconeogenesis?

A pathway that makes glucose.

How are many biosynthetic pathways related to catabolic pathways?

They are often reversals of catabolic pathways.

What does the reductive TCA cycle make and do?

Makes acetyl-CoA and fixes CO2.

What can gluconeogenesis intermediates be used to build?

Cell components, including peptidoglycan building blocks NAM and NAG.

What three information-flow processes should you know?

DNA replication, transcription, and translation.

What is a gene?

A functional unit of genetic information encoded in DNA.

What is a genome?

All genetic material in a cell or virus.

What is a genotype?

The specific set of genes carried in a genome.

What is a phenotype?

The set of observable characteristics.

What is an operon?

A cluster of genes plus regulatory elements.

What is polycistronic organization in the lecture's operon context?

Multiple genes can be transcribed together in one mRNA.

What is a promoter?

A regulatory DNA site where RNA polymerase binds to begin transcription.

What is an operator?

A DNA site where repressor proteins bind to block transcription.

What does an inducer do in the lecture's operon description?

Binds a repressor so it cannot bind the operator, allowing transcription.

What are the three parts of a DNA nucleotide?

A sugar, a nitrogenous base, and a phosphate group.

What sugar is found in DNA nucleotides?

Deoxyribose.

Which DNA bases are purines?

Adenine (A) and guanine (G).

Which DNA bases are pyrimidines?

Cytosine (C) and thymine (T).

What is a deoxynucleotide?

A DNA base plus sugar plus phosphate group.

What is the overall structure of DNA?

A double helix made of two complementary strands.

What connects deoxynucleotides within a DNA strand?

Phosphodiester bonds.

What connects the two DNA strands?

Hydrogen bonds between complementary bases.

What are the DNA base-pairing rules?

A pairs with T; G pairs with C.

How many hydrogen bonds connect A-T?

Two hydrogen bonds.

How many hydrogen bonds connect G-C?

Three hydrogen bonds.

What does antiparallel mean for DNA strands?

The two strands run in opposite directions.

How is DNA size expressed?

In base pairs (bp).

How many base pairs are in one kilobase (kb)?

1,000 bp.

What is the E. coli chromosome size listed in the lecture?

4,640 kb, or 4.64 Mbp.

What small bacterial genome example is listed?

Mycoplasma: about 580 kb, encoding 480 proteins.

What is semiconservative DNA replication?

Each original strand serves as a template for a new strand.

What happens during semiconservative replication?

The DNA strands separate and each guides synthesis of a complementary strand.

How does prokaryotic DNA replication proceed, according to the lecture?

Bidirectionally from one origin, forming two forks moving in opposite directions.

Which protein binds the origin and promotes DNA strand separation?

DnaA.

In which direction does DNA polymerase synthesize DNA?

5′ to 3′.

What does DNA polymerase use as a template?

A single DNA strand.

What does DNA polymerase need to synthesize DNA?

A template, dNTPs, and a primer with a 3′ OH group.

Which DNA polymerase is the major DNA replication enzyme in bacteria?

DNA polymerase III.

What do single-strand binding (SSB) proteins do?

Bind to single-stranded DNA.

What does helicase do?

Uses energy to separate DNA strands by breaking hydrogen bonds.

What enzyme lays down the RNA primer?

DNA primase.

What does DNA gyrase (topoisomerase II) do?

Relieves DNA topological strain by cutting, passing DNA through, and resealing it.

Which antibiotic class is noted as targeting DNA gyrase?

Quinolones, including ciprofloxacin.

How is the lagging strand synthesized?

Discontinuously in Okazaki fragments.

What does DNA polymerase I do during replication?

Removes RNA primers and fills in the resulting gaps with DNA.

What does DNA ligase do?

Seals breaks in the DNA backbone.

What did Griffith's transformation experiments demonstrate?

Material from heat-killed virulent bacteria could transform live nonvirulent bacteria.

What were the two Streptococcus pneumoniae strains in Griffith's experiment?

Capsulated smooth (S) and non-capsulated rough (R) strains.

What happened when live R cells were combined with heat-killed S cells?

The mouse died; live R cells acquired traits that made them virulent.

What is transformation in the lecture's genetics context?

Uptake and incorporation of DNA that changes a cell's traits.