Cell Bio 1

What is a cell?

The basic unit of life, aqueous solution of organic molecules enclosed by a membrane with a capacity for reproduction and ability to carry out metabolism

How many cells in the human body?

10^13 cells

How many different kinds of cells in human body?

>200 different types of cells in the human body

What are the differences between prokaryotic and eukaryotic cells?

Prokaryotes

• No nucleus

• No organelles

• ~1um

• Single circular DNA

Eukaryotes

• Nucleus

• Organelles

• 10-100um

• Multiple linear DNA

Are viruses cells? Can they proliferate on their own?

No and no

The first self replicating molecule was made of what? Does it have catalytic function?

RNA which has catalytic activity (first genetic system)

What was Stanley Miller able to generate from inorganic molecules?

Amino acids

The eukaryotic cell arose from fusion of what two cell types?

Archea and eubacteria

Through what process did eukaryotic cells obtain mitochondria and chloroplast?

Endosymbiosis

Who coined the term “cell”?

Robert Hooke

Does all life on earth have the same ancestor?

Yes

What model organisms do we study that are prokaryotic?

Bacteria: E. coli

What model organisms do we study that are eukaryotic? (6)

Yeast: Saccharomyces cerevisiae

Arabidopsis thaliana (plants)

Drosophila melanogaster (genetics)

Caenorhabditis elegans (developmental lineage)

Zebra fish (vertebrate animals)

Mus musculus (mammals)

What is a primary cell culture? What are pros and cons of this?

Primary cells: cells straight from the tissue with no passages

Pros: behave similarly to their natural environment

Cons: usually composed of mixtures of cell types

What is a cell line? What are pros and cons of this?

Cell lines: Have at least one passage. Tumor cells are immortalized cell lines, can be passaged many times

Pro: cell population is homogenous and can manipulate their environment easily

Con: may behave differently from the cells in their natural environment

What is HeLa cell line?

Most widely used cancer cell line for biomedical research

How can you visualize a protein in a cell?

Fluorescent-labeled antibodies

What is common used to visualize proteins in living cells?

Expressing GFP tagged proteins

What determines resolution of an image?

Wave length

Does longer or shorter wave length result in higher resolution image?

Shorter wave length = higher resolution image

Does an electron or light microscope have a higher resolution image?

Electron

What are the functions of microscopy?

1. Magnification

2. Resolution

3. Contrast

What is fluorescence microscopy good for visualizing?

Distribution of protein in cell or tissue

What is transmission EM good for visualizing?

Cellular structure inside a cell

What is scanning EM good for visualizing?

Surface of the cell

What is freeze fracture EM good for visualizing?

Inside cell membrane

What is x-ray crystallography good for visualizing?

Structure of a molecule

What is the purpose of centrifugation?

To isolate cellular components

What is different centrifugation?

Cell components are separated by centrifugation at progressively higher speeds

What precipitates first in differential centrifugation?

Whole cells, nuclei, and cytoskeletons