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Cell Forms Comparison – Launching Pad for Cell Biology

by Georgina Cornwall, PhD
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    00:00 Before we move into the course, it's really important for us to establish what life is.

    00:06 Some might debate that viruses and prions are non living. But certainly, cells are living.

    00:13 So we're going to explore some brief comparisons between eukaryotic and bacterial or prokaryotic cells.

    00:20 Yes, there's another division, another type of cells called archaeas. But they're not really components of human body.

    00:26 We're going to be dealing primarily with bacterial cells and eukaryotic cells and on occasion throughout this course, we'll be exploring some mechanism of viruses.

    00:39 So comparing prokaryotic and eukaryotic cells, they both have ribosomes, they both have DNA.

    00:46 They both have cell membranes. Bacterial cells have cell walls whereas eukaryotic cells generally do not have cell walls.

    00:57 Plant cells have cell walls. And fungal cells have cell walls.

    01:02 However, animal cells lack a cell wall at all. Both cell membranes are composed of phospholipid bilayers.

    01:10 Both have ribosomes although prokaryotic and eukaryotic ribosomes are slightly different.

    01:18 We'll explore those in further lectures.

    01:22 And then in general, a eukaryotic cell is about ten times larger than a prokaryotic cell.

    01:29 And as I mentioned, in addition we'll be visiting viruses and prions briefly.

    01:34 Viruses, technically they are non living. They're composed of a protein capsid, so a protein outer coat with a nucleic acid or DNA core. Sometimes an RNA core in the case of retroviruses.

    01:49 In addition, some virus like the AIDS virus also have a viral envelope which has enveloped protein studded over the surface for recognition purposes.

    02:02 And finally, prions. Prions have given us some questions to think about because they contain no DNA. However, they're contacting other proteins, can cause them to fold in a different way.

    02:15 And they seem to have some sorts of genetic capacities, yet zero DNA.


    About the Lecture

    The lecture Cell Forms Comparison – Launching Pad for Cell Biology by Georgina Cornwall, PhD is from the course Introduction to Cell Biology.


    Included Quiz Questions

    1. Nuclear membrane
    2. Cell membrane
    3. Ribosomes
    4. Chromosome
    5. Cell wall
    1. …either DNA or RNA.
    2. …both DNA and RNA.
    3. …proteins only.
    4. …histones only.
    5. …lipoproteins only.
    1. Prions are infectious protein molecules having genetic capacity in the absence of DNA molecules.
    2. Prions are usually associated with a DNA or RNA molecule in a virus.
    3. Prions help in proper folding of DNA in a chromosome.
    4. Prions are the main component of ribosome structure.
    5. Prions participate in the transcription and translation processes.

    Author of lecture Cell Forms Comparison – Launching Pad for Cell Biology

     Georgina Cornwall, PhD

    Georgina Cornwall, PhD


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