Movement through the cell: Molecules have to move around the cell to do their jobs. Sometimes they go into, or out of an organelle. Our cells use Diffusion and Osmosis to do this job. But,……. How do large molecules get in?

Crossing the Membrane Nutrients must get in and wastes must get out. Signaling molecules received by a cell may need to get in, while signaling molecules sent by a cell need to get out. Fluid must be able to get in and out. Certain ions must be able to get in and out.

Types of transport: Passive Transport: Either by simple diffusion or through a membrane protein Requires NO Energy Active Transport: Requires Energy - ATP Always happens through a membrane protein and uses ATP to force a molecule across a membrane against concentration grandient

Big Stuff? Membrane Proteins are adequate for bring small molecules into the cell or out of the cell. However, a different kind of active transport is necessary to move large things into/out of the cell – vesicular transport. There are 2 types of vesicular transport: exocytosis and endocytosis

Exocytosis  Exocytosis literally means “out of the cell”  It accounts for hormone secretion, neurotransmitter release, mucus secretion, and, sometimes, ejection of wastes.  Inside the cell, the substance to be exported is enclosed in a membranous sac called a vesicle.  The vesicle will migrate to the PM fuse with it, and then rupture, spilling the contents into the extracellular space.

Endocytosis Reverse of exocytosis. Allows macromolecules to enter cells.  The substance is progressively enclosed by an enfolding portion of the plasma membrane.  This forms a vesicle which will pinch off the plasma membrane and enter the cytosol where it is typically digested. Types of endocytosis are:  Phagocytosis  Pinocytosis (a.k.a. bulk-phase endocytosis)  Receptor-mediated endocytosis

Phagocytosis Literally “cell-eating.” Cytoplasmic extensions called pseudopods “reach out and grab” large, solid material such as a clump of bacteria or cell debris, and then engulf it. The resulting vesicle is called a phagosome. Usually, the phagosome fuses with a lysosome, a membranous organelle that contains digestive enzymes, and its contents are digested. Macrophages and white blood cells are the most phagocytic cells in the body.

Pinocytosis Literally means “cell-drinking.” A bit of infolding plasma membrane surrounds a droplet of extracellular fluid containing dissolved molecules. This creates a tiny membranous vesicle. Most cells routinely perform this. Unlike phagocytosis, pinocytosis is unselective!

Photosynthesis and Respiration Where does your energy come from? Autotroph : - having the ability to make ones own energy (food). Heterotroph: - having to take energy from another organism. Plants Chemo-Autotrophs Us!

Your Body uses Chemical Energy ATP Adenosine Triphosphate Adenine Ribose Sugar Three phosphates ADP - Adenosine Diphosphate (only two phosphates) is converted to ATP In cells to store energy for cells! Using the energy - Cells break off the 3 rd phosphate and use the released energy.

Photosynthesis The PROCESS of using the energy from the sun to Convert CO 2 and Water into Glucose and O 2 The Equation: 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 6 Carbon Dioxides 6 Waters 1 Glucose (sugar) 6 Oxygens But it happens in two different Reactions Light Reaction and Dark Reaction

Light Reaction Take place inside the Chloroplast at a specific place. Stacks of individual “disks” called Thylakoids A stack of these thylakoids is called a Granum (grana = plural)

Chlorophyll molecules are arranged in Photosystems. PHOTON When a PHOTON of light strikes anywhere on the photosystem, electrons are passed to the center and ATP and NADPH are made. ADP P NADP+ H2OH2O ATP NADPH O2O2

The ATP and NADPH go outside the Grana into the space in the Chloroplasts called the Stroma Light Independent reaction This is where the “Light Independent reaction” takes place. a.k.a. : Calvin Cycle or “Dark Reaction” because it can happen in the dark. Melvin Calvin

The Light Independent Reaction goes as follows: CO 2 enters ATP ADP CO 3 NADPH NADP+ C 6 H 12 O 6 glucose Remaining CO units ATP ADP 3 – CO 5

For every 6 Carbon dioxide and 6 water molecules that enter the Chloroplast, 1 glucose and 6 Oxygen is created or 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 But what happens if we reverse the arrow? Now we are burning Sugar with Oxygen to get Water and Carbon dioxide.

What burns Sugar (glucose) and Oxygen together? All living things! This Process is called Cellular Respiration C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O ENERGY

Cellular Respiration Starts when Glucose enters the cell ! nucleus mitochondria Glucose Glycolysis: First step in Cellular Respiration where Glucose is split in half inside the cytoplasm. Process: Pyruvic Acids CC CCC C 2-ADP 2-ATP 2-NAD+2-NADH to the Mitochondria

Inside the Mitochondria: 2 Pyruvate Molecules 2 CO 2 Krebs Cycle 4 CO 2 8-NADH and 2-FADH 2 2 ATP Electron Transport H2OH2O 32 ATP Total 34 ATP The Two Pyruvate Molecules enter the Krebs Cycle. A total of 6 CO 2 and 2 ATP are Produced. NADH and FADH 2 enter the Electron Transport Chain. Water and 32 ATP are produced giving 34 total ATP produced in the Mitochondria. O 2 Enters

What happens if you can’t give the cell enough O 2 ? Pyruvic Acids CC CCC C 2-NAD+2-NADH 2-ADP 2-ATP After Glycolysis, if there is not enough O2 to go through cellular respiration, the cell converts the NADH into ATP and the Pyruvic acid breaks down into Lactic Acid Lactic Acid Fermentation Glycolysis Lactic Acid O2O2 X

Let’s Recap Photosynthesis converts Light energy from the sun into Sugar 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 ATP Respiration converts Sugar into usable energy – A T P Notice any similarities?

Review 1. Active Transport 2. Passive Transport3. Pinocytosos 4. Exocytosis5. Phagocytosis6. Autotroph 7. Heterotroph8. ATP9. ADP 10. Light Reaction11. Light Independent Reaction 12. Photon 13. Chlorophyll14. Cellular respiration15. Glycolysis 16. Pyruvic Acid17. Electron Transport Chain 18. Krebs Cycle 19. Lactic Acid Fermentation Questions: 1.Be able to describe the process of photosynthesis. 2.What is the difference between the light and light independent reactions? 3.Describe the steps in Cellular respiration. 4.What is the difference between Cellular respiration and Lactic Acid Fermentation?