1. Cytology

2. Objectives • What is cytology? • Anatomy of the cell – Nucleus, DNA, Cytoplasm, Organelles • Aerobic and anaerobic respiration • Photosynthesis

3. Cytology • What does ‘cytology’ mean? • The study of the structure and function of cells • Basic Structure • Nucleus (eukaryotes) • Cell membrane • Cytoplasm • Cytosol • Organelles

4. Basic Structure • Nucleus – control center • Cytoplasm – space outside nucleus surrounded by cell membrane • Contains • Organelles – tiny structures which perform functions for the cell • Cytosol – fluid around the organelles

5. Types of Cells • Prokaryote • Smaller & Simpler • Considered “primitive” • Lack membrane-bound organelles • No nucleus • Free floating genetic material • Bacteria

6. Types of Cells • Eukaryote • Membrane-bound nucleus • Membrane-bound organelles • Plant & animal cells

7. Eukaryotic Cell Anatomy

8. The Nucleus • Control center of cell – in charge of everything • Like the office of the school • Contains DNA – blueprints for making proteins and other essential compounds

9. The Nucleus • Nucleolus – small, dense region where ribosomes are formed • Nuclear envelope – double layered membrane surrounding the nucleus • Nuclear pores – control what moves into and out of the nucleus • DNA – Deoxyribonucleic acid – genetic material of life • Chromatin – long chains of DNA stretched out inside the nucleus • Chromosomes – short thick coiled up sections of DNA

10. DNA Structure • Building blocks of DNA are called Nucleotides • Consists of a phosphate, sugar and a nitrogenous base • 4 types of nitrogenous base • adenine (A) • thymine (T) • cytosine (C) • guanine (G)

11. Nucleotide Structure • DNA consists of two nucleotide chains wound together to form a double helix

12. DNA • Watson & Crick • 1953 • Discovered double-helix structure • Discovered complimentary base-pair rule • A – T • C – G • Why ‘triplet’? • Every group of 3 nitrogenous bases codes for one of the 20 amino acids!

13. DNA Triplet

14. DNA Triplet

15. Organelles

16. Organelles • Using your textbook or a laptop, research the function of each of the organelles list on the summary sheet. • Eukaryotic Cell Structure • Cell Anatomy • Cells Alive • How Big Are Cells?

17. Mitochondria • What do we know about mitochondria? • Power plant for the cell • Site of cellular respiration • Has it’s own DNA!!!

18. Cellular Respiration • Glucose gets broken down in the presence of oxygen to produce energy (exothermic or catabolic) • Carbon dioxide & water are the other by-products • C6H12O6 + 6O2 6CO2 + 6H2O + ENERGY • Releases lots of energy at a relatively slow, steady pace

19. Anaerobic Respiration • Glucose gets broken down without the use of oxygen (exothermic or catabolic) • Produces lactic acid = the “burn” • C6H12O6 2 C3H6O3 + Energy • Releases small amount of energy at a really quick rate

20. ATP • Adenosine triphosphate • Converts energy to make it useful to the cell • Aerobic respiration produces enough energy that it requires 36 ATP molecules • Anaerobic respiration produces enough energy that it requires only 2 ATP molecules

21. Animal cell vs Plant cell; what’s the difference?

22. Plant Cells • Contain special organelles called “plastids” • Chloroplasts – site of photosynthesis; contain green pigment (chlorophyll) - contain thylakoid discs stacked into columns called granum (grana – plural) • Amyloplasts – found in root cells of plants and their function is to store starch

23. Chloroplasts

24. Photosynthesis • Exact opposite reaction to cellular respiration • Carbon dioxide + water + energy (sunlight) = sugar (glucose) + oxygen 6CO2 + 6H2O + sun light C6H12O6 + 6O2 • Endothermic/anabolic reaction

25. Cytology Test • Friday, Sept. 30, 2011 • Review Sheet • Use the text or ask questions