1. Prokaryotic Cells Advanced Higher Biology

2. Prokaryotic Cells “ pro ” – before“ karyo “– nucleus Prokaryotes were probably the first forms of life on earth. Their heredity material (DNA) is not enclosed within a nuclear membrane. There are no membrane bound organelles within a prokaryotic cell.

3. Prokaryotic Cells The absence of a true nucleus only occurs in 2 groups. –Bacteria –Blue green algae (cyanobacteria) Five structures, which are always present in a prokaryotic cell, are: –cell wall, plasma membrane, cytoplasm, ribosome, circular DNA

4. Bacterial Cells Hove no membrane bound organelles Have a single circular molecule of DNA “naked” DNA – not associated with histones Cell wall made of peptidoglycan

5. Prokaryotic cells Structure Structureinformation Capsule Glycogalyx – firm or disorganised Adherence and protection Nucleoid Region containing bacterial chromosome Pili (fimbriae) Anchoring functions Flagella Motility; 3 parts – basal body, hook and filament Cell Wall Growth and division Peptidoglycan Plasma membrane Phospholipids Cell structures Cytosol – fluid filled portion Ribosomes – “free” or inner surface PM Spores and cysts Survive unfavourable environmental conditions (metabolically inactive)

6. Structure of a bacterial cell

7. Activity Copy and complete the following table Include organelles, DNA, RNA and protein synthesis, ribosome, cell division, cell wall, cellular organisation. prokaryoticEukaryotic organisms Cell size metabolism

8. Comparison of prokaryotic and eukaryotic cells prokaryoticEukaryotic organismsBacteria cyanobacteria Protista, fungi, plants, animals Cell size1 – 10 µm10 –100 µm metabolismAnaerobic and aerobic Aerobic organellesNo membrane bound organelles Nucleus, mitochondria, chloroplasts, RER, SER

9. prokaryoticEukaryotic DNACircular DNA in cytoplasm DNA organised into chromosomes bounded by nuclear envelope RNA and Protein Synthesis Synthesised in same compartment RNA synthesised and processed in nucleus Protein synthesis in cytoplasm Ribosomes70S Type80S Type Cell DivisionBinary fissionMitosis or meiosis Comparison of prokaryotic and eukaryotic cells

10. Essay – 15 marks List the similarities and differences between prokaryotic and eukaryotic cells