BIOL1130 Lecture Notes - Lecture 9: Plant Cell, Lysosome, Amphiphile
Week 5 Unity and Diversity of Cell structure (chap 4)
Prokaryotes/ Prokaryotic cell / Bacterial cell
• Unicellular, single celled microorganism that has no distinct nucleus with a
membrane and other specialized organelles
• does not contain a nucleus with distinc membrane
• Does not contain membrane-bound organelles such as ER/ mitochondria/chloroplast
• Lack cytoskeletal structures such as microfilaments/ microtubules
• Exception → Cyanobacteria → a bacteria that undergoes photosynthesis, has light-
trapping pigments (chlorphyll a and b) that is analogous to thykaloid membrane of
chloroplast (that is eukaryotic)
• Have plasma membrane
• Does’t have uleus erae
• DNA is coated with proteins
• DNA is in the form of nucleoids – irregularly shaped region
• Therefore nucleoids (DNA) is coated with proteins
Eukaryotes
• Have nucleus with membrane, DNA is in the form of chromosomes
• Oldest eukaryotes have chloroplasts, resembling green algae.
• Have plasma membrane and nucleus membrane
• DNA is coated with proteins
• Therefore chromosomes (DNA) is coated with proteins
A phospholipid is amphipathic – a phospholipid is a molecule with hydrophobic and
hydrophilic region
Biological membranes – e.g. plasma membrane, nucleus membrane
• are lipid bilayers that phospholipids ( hence it has hydrophilic EXTERIOR and
hydrophobic INTERIOR)
• lipid bilayers are nearly impermeable to everything
• TRANSPORT -mvt across memb. Req. specific transporter proteins
Features of cell
• Cytoplasm – space surrounded by plasma membrane – contains cytosol and
ribosomes
• Cytosol- semi fluid material IN cytoplasm, include organelles, no DNA present in
cytosol
• Ribosomes – bigger in eukaryotes 80S, synthesize proteins
• Plasma membrane – keeps contents concentrated
• Chromosomes/Nucleoids- genes in the form of DNA
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Document Summary
Week 5 unity and diversity of cell structure (chap 4) Eukaryotes: have nucleus with membrane, dna is in the form of chromosomes, oldest eukaryotes have chloroplasts, resembling green algae, have plasma membrane and nucleus membrane, dna is coated with proteins, therefore chromosomes (dna) is coated with proteins. A phospholipid is amphipathic a phospholipid is a molecule with hydrophobic and hydrophilic region. Biological membranes e. g. plasma membrane, nucleus membrane: are lipid bilayers that phospholipids ( hence it has hydrophilic exterior and hydrophobic interior) lipid bilayers are nearly impermeable to everything, transport -mvt across memb. Organelles in eukaryotic cells (protista, plantae, animalia, fungi: at least one membrane, seperate incompatible processes, organelles do(cid:374)"t interfere other with each others, have extensive endomembrane system ( organelles have membranes )(membranes are present in the cell system) Nucleus: has nuclear envelope that surrounds the nucleus- nuclear envelope is. Double membrane- inner and outer- inner has bilayer-outer has bilayer: nucleur envelope- outer membrane has continuous er.