1. Cell Biology

2. Cells Definition: The smallest most basic unit of all living things that is still considered alive. Examples of cells: bacteria, muscle cells, nerve cells, fatty tissue is made of fat cells, skin, bone marrow, pancreas cells…..

3. Gametes (Sex Cells) EggSperm

4. Classification of Cells ProkaryoticDo not have membrane bound organelles (structure within a cell that are surrounded by a membrane). Most notably, no nucleus. Make up single celled organisms called Bacteria In fact, the only prokaryotic cells present today are Bacteria cells

5. Examples of Prokaryotic Cells Billion year old bacteria Rod Shaped Bacteria

6. Classification of Cells Eukaryotic:Do have membrane bound organelles within the cell. So, do contain a nucleus. Make up both single celled and multicellular organisms. Examples of eukaryotic organisms include: animals, plants, amoeba, paramecium….

7. Eukaryotic Cell detail: note the many membrane bound organelles

8. Examples of Single Celled Eukaryotic Cells Paramecium Diatom Algae

9. Viruses Not necessarily living: not a cell because it lacks the ability to replicate on it’s own. Made up of a protein coat (shell) surrounding a nucleic acid molecule (either DNA or RNA). Function: inject DNA/RNA into cell and turn cell into a virus factory that makes many copies of the virus.

10. More Viral Structures Microscope picture of WSSV virus: kills shrimp. (source: Wageningen University, Laboratory of Virology) Ebola Virus Virus that causes pink eye Bacteriophage

11. Compare/Contrast Prokaryotic, Eukaryotic Cells and Viruses Q: Which have an outer membrane? A: Prokaryotic/Eukaryotic cells Q: Which have a protein coat? A: Viruses Q: Which have DNA? A: All Q: Which rely on other cells for replication? A: Viruses Q: Which have membrane bound organelles? A: Eukaryotic cells Q: Which can live on their own? A: Prokaryotic/Eukaryotic cells Q: Which can cause disease? A: All

12. Cell Membrane Structure of all cells that regulates what enters and leaves the cell. Selectively permeable: Some chemicals can pass through membrane while others cannot

13. Structure of Cell Membrane 1. Phospholipid bilayer: fluid layer 2. Proteins imbedded in the lipid bilayer act as pumps/channels, receptors, and identification markers 3. Cholesterol attaches to phospholipid tails, inhibiting movement. Result is cell membrane is less fluid.

14. Function of Cell Membrane It is a barrier between the interior of the cell and its exterior environment. Both the internal and external environment of cells are liquidy: water solvent with various solutes such as proteins, gases, ions, sugars, amino acids, nucleotides.

15. Movement of Substances across the Cell Membrane Passive Transport: Does not require cellular energy Types of Passive Transport include diffusion and osmosis Active Transport Do require cellular energy Types of active transport include movement through a protein pump, endocytosis, and exocytosis

16. Passive Transport: Diffusion Definition of Diffusion: When molecules move from an area of greater molecule concentration (conc.) to an area of lesser molecule concentration. Example: Perfume diffuses through the air. The perfume molecules move from an area of greater perfume molecule conc. to an area of lesser perfume conc. Another (more gross) example: Someone farts…..

17. Passive Transport: Diffusion Examples 1:2:

18. Passive Transport: Diffusion Examples 3:

19. Gas exchange in our lungs is an example of diffusion in our bodies.

20. Water absorption in our skin when we swim or take a bath is also an example of Diffusion in our bodies (as water diffuses into our skin, the skin puffs up; however, because it is attached to the inner layer of skin it wrinkles)

21. Passive Transport: Osmosis Definition of Osmosis: When water molecules diffuse across a selectively permeable membrane. Examples: When there is a higher water concentration outside a cell than inside a cell, the water molecules will diffuse across the cell membrane into the cell When water passes through a plastic bag with holes that are only big enough for the water to pass through but nothing else.

22. Passive Transport: Osmosis Example

23. Passive Transport: Osmosis Example with RBC

24. Active Transport: Endocytosis Using cellular energy to actively take something into a cell.

25. Active Transport: Exocyctosis Using cellular energy to actively expel something from a cell.

26. Secretion of Proteins 1. Proteins are made at the Ribosomes. 2. From there they travel through the cell in the Endoplasmic Reticulum. 3. A vesicle pinches off from the Endoplasmic Reticulum and travels to the Golgi Apparatus and fuses to it. 4. The proteins are modified in the Golgi Apparatus 5. Then a vesicle pinches off from the endoplasmic reticulum, travels to the cell membrane and fuses to it. 1. 2. 3. 4. 5. Ribosomes

27. Examples of Protein secretions Saliva Venom in snakes and scorpions Digestive enzymes in our stomach and pancreas Neurotransmitters that carry messages between our nerve cells Poisons in spiders and stinging jellyfish Enzymes in tears

28. Energy in cells: involves two organelles Photosynthesis: Chloroplasts in plant cells Organisms that make their own food through photosynthesis are called autotrophs. Cell respiration: Mitochondria in plant and animal cells Organisms that need to consume other living things for food are called heterotrophs.

29. 1. Sunlight captured by chloroplasts 2. Chloroplasts make glucose (cellular food) 3. Organisms eat plants, or other animals that eat plants, and take in glucose 4. Glucose diffuses into a cell through a membrane protein 5. Glucose broken down in mitochondria to release cellular energy (ATP)

30. Photosynthesis Equation: 6 CO 2 + 6 H 2 O C 6 H 12 O 6 + 6O 2 Sunlight Energy The light energy from the sun gets trapped into a molecule of glucose. Where do the reactants come from? Where do the products end up?

31. Cell Respiration C 6 H 12 O 6 + 6O 2 6 CO 2 + 6 H 2 O ATP When glucose is broken down in the mitochondria, the energy that was trapped in the glucose molecule is released as cellular energy. The cell uses cellular energy for growing, moving, reproducing, making proteins, building biomolecules, digesting biomolecules.