Cell Biology Midterm

What are the universal features of all cells on earth: functional macromolecules,
chemical components of a cell

Functional: Nucleic Acids (RNA, DNA, Central dogma), proteins, lipids, carbs. Chemical: Water, Hydrogen, Nitrogen, oxygen, phosphorus sulfur. Ions: Na, K, Ca, Cl, HCO, ATP,

Understand the idea of central dogma of molecular biology and use it to explain
biodiversity.

Central dogma: DNA —> RNA —> Protein. Mutations and recombination of DNA result in biodiversity

The diversity of genomes and the tree of life: main domains and kingdoms of life,
how genetic information is stored and conveyed, origin of new genes, homolog,
paralog and ortholog, etc.

Archea, Bacteria, Eukaryotes. Genetic information is stored as chromosomes, circular in bacteria and linear in eukaryotes.

Archea

Prokaryotic, live in extreme environments

Bacteria

Prokaryotic single celled organisms, lack a nucleus and membrane bound organelles. Single circular chromosome.

Eukaryotic

Multicellular organisms Plants, animals, fungi, yeast

Homologs

Genes related by descent from a common ancestor

Paralogs

Genes within the same species that arose from duplication and may have new functions

Orthologs

Genes in different species that evolved from a common ancestor and retain the same function

Eukaryotic cells

Linear chromosomes in nucleus, multiple chromosomes, wrapped around histone proteins, large amounts of introns and regulatory regions, genes are monocistronic (one per mRNA), separated: transcription in nucleus, translation in cytoplasm. Complex regulation with enhancers, silencers, and chromatin remodeling

Prokaryotes (bacteria & archea)

Circular chromosomes found in nucleoid, one chromosome, supercoiled (no histones), mostly coded DNA, few non coding regions, genes are polycistronic (multiple genes per mRNA), transcription and translation occurs simultaneously in cytoplasm, Simple regulation.

Understand the theory of fluorescence (i.e. the Jablonski diagram)

Fluorescence is the process where a molecule absorbs light at a shorter wavelength (higher energy) and then emits light at a longer wavelength (lower energy).

How does the wavelength of the light used to illuminate a specimen affect the
ability to resolve objects within the specimen? How is the resolution of an objective
calculated?

Shorter wavelengths= better resolution. wavelength/2NA

GFP

GFP (Green Fluorescent Protein) is a naturally occurring fluorescent protein, It emits green light (~509 nm) when exposed to blue or UV light.

Do you think genetic fluorescent labeling can be combined with traditional
immunohistochemistry method? If so how do you design an experiment to show
cellular locations of at least three different proteins (including the genetically
labeled protein) in the same cell culture? Why has GFP become a very useful
protein for live cell observation?

This method allows scientists to track both genetically encoded fluorescent proteins and antibody-labeled proteins, enabling detailed localization studies of different cellular components.

Study the main organelle table and understand the name, main function of each
organelle