1. The Cell

3. Living Organisms All organisms except Viruses are cellular Only Two fundamental types

4. Fundamental Cell Types Prokaryotic : Bacteria & Archaea Eukaryotic : Animals, plants, protozoa, fungi & algae

5. Viruses structure : protein coat + genetic material ( DNA or RNA ) Virus is not a cell.

6. Virus *Viruses structure : protein coat + genetic material ( DNA or RNA ) *Virus is not a cell.

7. Prokaryotic Single cell Size generally small (1-10μm) Nucleus absent DNA lies in cytoplasm(circular molecule ) ( DNA+non-histone protein) No membrane bound organelles Hair like flagella are simple tubes. Ribosomes, are smaller in size 70 S Simple internal structure Cell division by simple binary fisssion Eukaryotic Single or multicellular Size generally large (10-100μm) Nucleus present DNA lies in nucleus. (chromosomes; DNA +histone +non-histone proteins ) There is membrane bound organelles Flagella are complex supported by 9+2 tubes. Ribosomes are larger in size 80 S Complex internal structure Cell division by mitosis Cells

9. Prokaryote Cell Structure

10. The Bacterial Cell Structure The Envelope & Capsule Pili & Flagella Cytoplasm & Inclusions

11. The Envelope & Capsule The bacterial envelope can be a three layered structure – Outer Membrane – Cell Wall – Cytoplasmic Membrane A capsule may or may not surround the envelope

12. Pili Straight hair like projections made of protein pilins May be short or several cell lengths long

13. The Eukaryotic Animal Cell

14. The Eukaryotic Plant Cell

15. Eukarytotic Structures External structures  cilia, flagella Cell walls, Cell membranes Cytoplasmic inclusions – Ribosomes – Cytoskeleton – Centrioles & Centrosomes

16. Eukarytotic Structures Nucleus & chromosomes Endoplasmic Reticulum (rough & smooth) Golgi Body Lysosomes Mitochondria & Chloroplasts

17. Nucleus & contents

18. Mitochondria

19. Endoplasmic Reticulum (rough & smooth)

20. Functions Of Cell Organelles Nucleus : containing the chromosomes which carry the genetic information in DNA. Mitochondria : provide the energy to cell,generates ATP. Riobosomes : sites of protein synthesis. Endoplasmic reticulum : synthesis of secretary proteins and carbohydrates.

21. Golgi apparatus : transport molecules out of cells and to other organelles. Lysosomes : degradation of metabolites and cellular component after cell death. Peroxisomes : removal of H2O2 and other oxidizing radicals. Chloroplasts ( in plants ) : photosynthesis. Vacuoles ( in plants ) : degradation and storage.

22. Cell Chemical composition-by weight : 70% water 7% small molecules salts Lipids amino acids nucleotides 23% macromolecules Proteins Polysaccharides lipids

23. The proteins are the most prominent biomolecules in the cell, making up over 50% of the dry weight. There is 3000 different kinds of protein molecules ( 20 a.a can be arranged in different sequence to give a huge number of different proteins) The second most abundant biomolecules are nucleic acids. These are followed by carbohydrates & lipids. All living cells contain approximately the same proportion of the major classes of biomolecules as in E.Coli.( in human there is about 100.000 different kinds of proteins ) The relative amounts of the major classes of biomolecules in living organisms

24. Major molecular component Approxmate No of Molecular species Percent total weighComponent 170Water 300015Proteins Nucleic acids 11DNA 10006RNA 503Carbohydrates 402Lipids 5002Building-block molecules&intermediates 121Inorganic ions Example E.Coli