BIO 105 1st Edition Lecture 6Energy, Enzymes, and Membrane TransportLecture Outline:I. Know the significance of ATPII. Be able to identify Endergonic reactions and Exergonic reactionsIII. Know the difference between Passive Transport, Active Transport, Diffusion and OsmosisIV. Know the characteristics of Light Independent Reactions and Light Dependent Reactions ATP- main energy carrier in cells, makes everything run in your body- Can give up phosphate group to another molecule- releases energy- The energy in an ATP molecule- rebuilds cell’s DNA synthesizes and builds enzymes Endergonic reactions= Anabolic Pathway- Absorb energy (or add in energy) and yield projects rich in potential energy (you have more energy)- Putting in energy- Ex: Photosynthesis Exergonic reactions = Catabolic Pathways- Breaking it down, taking it out, less energy- Losing energy- Yield Products that contain less potential energy than their reactants- Ex: Aerobic Respiration**Remember EXergonic means the energy has to Exit Enzymes- 5 characteristics1. Enzymes speed up metabolic reactions by lowering energy barriers2. Enzymes are substrate specific- react with specific substances (LOCK AND KEY FIT)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.3. The active site is an enzyme’s catalytic center- causes reaction4. A cell’s physical and chemical environment affects enzyme activity (ie. Salt, pH, etc)5. Enzymes are reusable-they are not destroyed- Enzymes are proteins Activation Energy- For a reaction to occur, an energy barrier must be surmounted- this is the energy of activation- Enzymes make the energy barrier smaller Factors Influencing Enzyme Activity1. Coenzymes and cofactors2. Allosteric regulators3. Temperature4. pH5. Salt Concentration Passive Transport- Does not require energy inputs- Solutes diffuse through a channel inside the protein’s interior or move directly through- Ex: A lot of people in the elevator rush out when the doors open to leave a place from a highly concentrated area to a less concentrated area Active Transport- Requires ATP- Pumps solute against its concentration gradient- Ex: A lot of people in the elevator and another family of forces their way into the elevator- Active Transport- proteins act as pumps, moving substances across membrane against concentration gradient- usually using ATP Diffusion- simple and facilitated- The passive net movement of like molecules or ions down a concentration gradient- Diffusion- Hydrophobic molecules and very small uncharged non- polar molecules diffuse directly through membrane (passive)- Facilitated Diffusion- Hydrophilic substances and larger molecules diffuse through membranes with assistance of transport proteins (passive) Factors Affecting Diffusion Rate- Steepness of concentration gradient, steeper gradient faster diffusion- Molecular size, smaller molecules faster diffusion- Temperature, higher temperature faster diffusion- Electrical or pressure gradients Osmosis- Osmosis- passive movement of water down its concentration gradient (passive) Hypotonic solution- Make plants “Turgid” (plump)- swell healthy state- plant prefer to be hypotonic solution- More water outside the plant, the water wants to be on the inside of the plant Other Membrane Traffic- Endocytosis- movement into cello Phagocytosis- cell eating, bigger moleculeso Pinocytosis- cell drinking, little droplets of fluido Receptor- Mediated- Cholesterol- Exocytosis- movement out of cellLecture 10- Photosynthesis Chlorophylls- Photosynthetic pigments in plants, green algae, and some bacteria- Absorb all wavelengths but green/ yellow green- Chlorophyll “a” greatest Photosynthesis- Light- Dependent reactions (cyclic and noncyclic)o Occur in Chloroplasto Occur in Thylakoid membrane systemo Cyclic Pathway- ATP forms, require photsystemo Noncyclic Pathway- ATP and NADPH form, water is split and oxygen released, requires two photsystems- Light- Independent reactions ( Calvin- Benson Cycle)o Make Glucoseo Occur in Chloroplasto Reactions occur in the stromao Thylakoil membrane- water gets split, oxygen is released, Hydrogen runs the ATPsynthate