1. DMI 261 Radiation Biology and Protection Unit 6 The Human Cell Cell Biology Review

2. Principle Cell Molecules Water80% Water80% Proteins15% Proteins15% Lipids 2% Lipids 2% Carbohydrates 1% Carbohydrates 1% Nucleic Acids 1% Nucleic Acids 1%

3. Cell’s Chemical Composition

4. Nucleic Acids RNA RNA DNA DNA –Double helix –Sugar-phosphate chains –Nitrogenous bases

5. Nitrogenous Bases Purines – Adenine and Guanine Purines – Adenine and Guanine Pyrimidines – Thymine and Cytosine Pyrimidines – Thymine and Cytosine –adenine only bonds with guanine –thymine only bonds with cytosine –Hydrogen bonds hold the bases together

6. Cell Structure

7. Cell membrane Cell membrane –Barricade –Controls passage of water and other materials in and out of the cell. Cytoplasm Cytoplasm –Protoplasm that exists outside of the nucleus.

8. Organelles Endoplasmic Reticulum Endoplasmic Reticulum –Transportation system for food and communication with outside environment –Rough have ribosomes –Smooth do not

9. Organelles Golgi Apparatus Golgi Apparatus –Concentrates, packages and transports enzymes and hormones through the cell membrane

10. Organelles Mitochondria Mitochondria –Power house of the cell –Produces energy for cell activity by breaking down nutrients

11. Organelles Lysosomes Lysosomes –Garbage disposals –Break down large molecules that enter the cell –Contain digestive enzymes that can destroy a cell if its membrane ruptures

12. Organelles Ribosomes Ribosomes –Protein factories –Make proteins as instructed by mRNA

13. Organelles Centrosomes Centrosomes –Contain centrioles which help form mitotic spindles

14. Organelles Nulceus Nulceus –Heart of the cell –Contains DNA, nucleolus (RNA), controls cell division and all other cellular activity

15. Cell Division Multiplication process by which one cell forms two or more cells Multiplication process by which one cell forms two or more cells

16. Mitosis Process by which somatic cells divide Process by which somatic cells divide

17. Interphase Period of cell growth that occurs before mitosis. Period of cell growth that occurs before mitosis. DNA replication occurs here. DNA replication occurs here.

18. Cell Cycle G1, S, and G2 = parts of interphase that lead up to mitosis

19. Stages of Mitosis

20. Meiosis Method by which germ cells (reproductive) divide in sexually reproducing plants and animals. Method by which germ cells (reproductive) divide in sexually reproducing plants and animals. Only ½ of the chromosomes are produced. Only ½ of the chromosomes are produced. Process of reduction division where the cell divides twice but DNA is replicated only once. Process of reduction division where the cell divides twice but DNA is replicated only once.

21. Meiosis

22. END REVIEW END REVIEW