Video Notes Review: Mauna Loa CO2, Hokusai, Proteins, and DNA Replication

A set of question-and-answer flashcards covering CO2 data from Mauna Loa, Hokusai's Great Wave, protein structure, and the basics of DNA replication.

What is the approximate weekly atmospheric CO2 level at Mauna Loa in 2025?

Around 430 ppm (parts per million).

What is the data source for the Mauna Loa CO2 measurements shown?

Tans & Keeling (2025).

What unit is used to measure atmospheric CO2 in the Mauna Loa record?

ppm (parts per million).

What overall trend do Mauna Loa CO2 measurements show from 2020 to 2025?

A continuing increase in CO2 concentration.

Who painted 'The Great Wave off Kanagawa'?

Katsushika Hokusai (1760–1849).

What are the alternate titles for Hokusai's famous wave print?

Under the Wave off Kanagawa (Kanagawa-oki Nami-ura).

When did Hokusai live?

1760–1849.

What are proteins made of?

Polypeptides built from amino acids.

What are the four levels of protein structure?

Primary, Secondary, Tertiary, and Quaternary.

What is meant by the primary structure of a protein?

The linear sequence of amino acids in a polypeptide.

What stabilizes alpha helices and beta sheets in proteins?

Hydrogen bonds between the peptide backbone (secondary structure).

What is an alpha helix?

A secondary structure where the polypeptide chain twists into a right-handed helix.

What is a beta sheet?

A secondary structure where strands align side-by-side and are stabilized by hydrogen bonds.

What is the tertiary structure of a protein?

The overall three-dimensional folding of a single polypeptide.

What is the quaternary structure of a protein?

The assembly of multiple polypeptide subunits into a functional protein.

What are the three main components of an amino acid?

Amino group, carboxyl group, and an R-group (plus a hydrogen on the alpha carbon).

What is a peptide bond?

The covalent bond linking amino acids in a polypeptide chain.

Proteins are polymers. What is the monomer unit they are built from?

Amino acids.

Name at least three functional roles of proteins.

Enzymes (catalyze reactions), defense (antibodies), hormones/receptors, transport, movement, and structural support.

What proteins mediate signaling and transport in cells?

Receptors, transport proteins, and signaling molecules.

Which enzyme adds most nucleotides during DNA replication?

DNA polymerase III.

Which enzyme removes RNA primers during DNA replication?

DNA polymerase I (5' to 3' exonuclease).

What initiates DNA synthesis by providing a starting 3' end?

RNA primer.

What is a replication fork?

The active site where DNA is unwound and replication proceeds.

What is a replication origin?

The specific DNA sequence where replication begins.

What does bidirectional replication mean?

Replication proceeds in two directions from the origin.

What are Okazaki fragments?

Short DNA fragments synthesized on the lagging strand.

Which enzyme seals Okazaki fragments?

DNA ligase.

Which enzyme relieves torsional strain ahead of the replication fork?

Topoisomerase.

Which enzyme unwinds the DNA double helix at the fork?

Helicase.

What is the role of single-stranded binding proteins (SSBs)?

Stabilize single-stranded DNA during replication.

Which strand is synthesized continuously toward the fork?

Leading strand.

Which strand is synthesized discontinuously away from the fork?

Lagging strand (as Okazaki fragments).

In what direction is DNA synthesized?

5' to 3' direction.

What is a 'nick' in the newly formed DNA strand?

An unbonded region in the sugar-phosphate backbone that is sealed by DNA ligase after primer removal.

What is the role of primase?

Lays down an RNA primer to start DNA synthesis.

What happens after RNA primers are removed?

DNA polymerase III fills in the gaps with DNA nucleotides.

Why must RNA primers be replaced with DNA?

To create a continuous DNA backbone and complete the genome copy.