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As you come in,

As you come in,. Materials: PICK UP A COPY OF THE LAB Notes pages and pencil The Plan: Macromolecule review Macromolecule Quiz Begin Eggcellent Lab Take Energy in a Cell notes The Assessment: Cell Organelle Quiz on Monday. Flagella and Cilia.

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As you come in,

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  1. As you come in, • Materials: • PICK UP A COPY OF THE LAB • Notes pages and pencil • The Plan: • Macromolecule review • Macromolecule Quiz • Begin Eggcellent Lab • Take Energy in a Cell notes • The Assessment: • Cell Organelle Quiz on Monday

  2. Flagella and Cilia Microtubules that allow these single-celled organisms (protists) to move.

  3. Macromolecule Review • General Information: • Organic vs. inorganic molecules • Monomer vs. polymer • Dehydration synthesis vs. hydrolysis • Carbohydrate monomer, function, test • Lipid monomer, function, test • Protein monomer, bonds, function, test • Nucleic acid monomer, monomer parts, function

  4. Energy and the Cell • Energy of Chemical Reactions • Basics of Energy • Enzymes & Substrates • Movement of Substances • Passive Transport: Diffusion & Osmosis • Active Transport: Proteins, Exocytosis, & Endocytosis • Energy Organelles • Chloroplasts • Mitochondria

  5. Basics of Energy • Energy is defined as the capacity to do work • All organisms require energy to stay alive • Energy makes change possible, for example chemical changes • Two types of energy: • Kinetic Energy: energy that is actually doing work • Potential Energy: stored energy

  6. Basics of Energy • First law of thermodynamics • “Law of Conservation of Energy” • Energy can be changed from one form to another • Energy cannot be created or destroyed • Second law of thermodynamics • Energy changes are not 100% efficient

  7. Basics of Energy • Cells carry out thousands of chemical reactions • The sum of these reactions constitutes cellular metabolism

  8. Basics of Energy • There are two types of chemical reactions: • Endergonic reactions absorb energy and yield products rich in potential energy • AKA: Endothermic reactions Products Amount of energy INPUT Potential energy of molecules Reactants

  9. Basics of Energy • Exergonic reactions release energy and yield products that contain less potential energy than the reactants • AKA: Exothermic reactions Reactants Amount of energy OUTPUT Potential energy of molecules Products

  10. Enzymes Biological catalysts Lower activation energy needed for a chemical reaction in the cell

  11. Most enzymes are proteins(tertiary and quaternary structures) Act as catalyst to accelerate a reaction Not permanently changed in the process Enzymes 11

  12. Are specific for what they will catalyze Are reusable End in –ase Sucrase Lactase Maltase Enzymes ENZYME 12

  13. Enzymes work by weakening bonds which lowers activation energy Enzymes 13

  14. Without Enzyme With Enzyme Free Energy Free energy of activation Reactants Products Progress of the reaction Enzymes 14

  15. The substance (reactant) an enzyme acts on is the substrate. Enzyme Enzymes Substrate Joins Forms an Enzyme-Substrate Complex 15

  16. Active Site: A restricted region of an enzyme molecule which binds to the substrate. Enzyme Enzymes Active Site Substrate 16

  17. Enzymes are specific. The shape of the active site only fits a certain substrate. An enzyme that hydrolyzes protein will not act on starch. Enzyme Enzymes Active Site Substrate 17

  18. Induced fit: A change in the shape of an enzyme’s active site Induced by the substrate Enzymes 18

  19. What Affects Enzyme Activity? Environmental Conditions Extreme temperatures are most dangerous (high temp can denature (unfold) the enzyme) pH (need to remain 6-8) Tonic concentration (salt ions) Enzyme Inhibitors Competitive Inhibitors: chemicals that look like the normal substrate and compete for the active site Noncompetitive Inhibitors: chemicals that do not enter the active site but bind to another part of the enzyme causing the enzyme to change shape. Enzymes 19

  20. Competitive Inhibitor Enzyme Substrate 20

  21. Noncompetitive Inhibitor Enzyme active site altered NonCompetitive Inhibitor Substrate 21

  22. As you come in, • Materials: • Notes pages and pencil • Eggcellent Lab • PICK UP 5 PIECES OF PAPER • The Plan: • Macromolecule Quiz – return papers • Day 1: Eggcellent Lab • Take Energy in a Cell notes • Start Cell Organelle flipbook • The Assessment: • Cell Organelle Quiz on Monday

  23. Movement of Substances Moving necessary molecules into and out of the cell through the cell membrane

  24. Function: Cell membranes organize the chemical reactions making up metabolism by controlling the flow of substances into and out of the cell. Membranes are selectively permeable. Cell Membrane 24

  25. Cell Membrane Head • Phospholipids are the main structural components of membranes • Membrane phospholipids form a bilayer • They each have a hydrophilic (polar) head and two hydrophobic (nonpolar) tails Symbol Tails

  26. Cell Membrane • In water, phospholipids form a stable bilayer • The heads face outward and the tails face inward Water Hydrophilicheads Hydrophobictails Water

  27. Cell Membrane • The membrane is a fluid mosaic of phospholipids and proteins • Phospholipid molecules form a flexible bilayer • Cholesterol and protein molecules are embedded in it • Carbohydrates act as cell identification tags

  28. The plasma membrane of an animal cell Glycoprotein Carbohydrate (of glycoprotein) Fibers of the extracellular matrix Glycolipid Phospholipid Cholesterol Microfilaments of the cytoskeleton Proteins CYTOPLASM

  29. Cell Membrane • Proteins make the membrane a mosaic of function • Some form cell junctions • Others transport substances across the membrane • Some are receptors for chemical messages Messenger molecule Receptor Activated molecule Signal transduction Transport Enzyme activity

  30. Cell Membrane Molecule of dye Membrane EQUILIBRIUM • FOCUS: Transport • Passive transport • Active transport • In passive transport, substances diffuse through membranes without work by the cell • A type of diffusion • Substances spread from areas of high concentration to areas of lower concentration EQUILIBRIUM Passive transport = no energy needed

  31. Cell Membrane Hypotonicsolution Hypertonic solution • Osmosis is the passive transport of water. • In osmosis, water travels from an area of lower solute concentration to an area of higher solute concentration Selectivelypermeablemembrane Solutemolecule HYPOTONIC SOLUTION HYPERTONIC SOLUTION Water molecule Water moves to water down one side of the membrane. Selectivelypermeablemembrane Solute molecule with cluster of water molecules NET FLOW OF WATER

  32. Cell Membrane • Achieving water balance between cells and their surroundings is crucial. • Osmosis causes cells to shrink in a hypertonic solution and swell in a hypotonic solution • The control of water balance(osmoregulation) is essential for organisms Isotonic = cell and solution are at Equilibrium No Movement of Water ISOTONIC SOLUTION HYPOTONIC SOLUTION HYPERTONIC SOLUTION ANIMALCELL (1) Normal (2) Lysing (3) Shriveled Plasmamembrane PLANTCELL (4) Flaccid (5) Turgid (6) Shriveled

  33. Cell Membrane • Transport proteins in the cell membrane facilitate diffusion across the membrane. • Small nonpolar molecules diffuse freely through the phospholipid bilayer • Many other kinds of molecules pass through selective protein pores by facilitated diffusion Solutemolecule Transportprotein Will energy be needed?

  34. Cell Membrane • In active transport, cells use energy. • Transport proteins can move solutes across a membrane against a concentration gradient, which means from low concentration to high concentration. • Active transport requires ATP

  35. FLUIDOUTSIDECELL Phosphorylated transport protein Transportprotein • Active transport in two solutes across a membrane Firstsolute 1 First solute, inside cell, binds to protein 2 ATP transfers phosphate to protein 3 Protein releases solute outside cell Second solute 4 Second solute binds to protein 5 Phosphate detaches from protein 6 Protein releases second solute into cell

  36. Cell Membrane • Other active transport methods: Exocytosis and endocytosis transport large molecules. • Exocytosis: a vesicle from inside the cell may fuse with the membrane and expel its contents outside of the cell. FLUID OUTSIDE CELL VESICLE CYTOPLASM Is energy needed?

  37. Cell Membrane • Endocytosis: the membrane may fold inward, trapping material from the outside. A vesicle forms and moves into the cell. AKA: phagocytosis Is energy needed?

  38. Chloroplasts & Mitochondria Organelles that make energy available for cellular work (like active transport)

  39. Chloroplasts & mitochondria • Chloroplastscarry out photosynthesis, using solar energy to produce glucose and oxygen from carbon dioxide and water • Mitochondria consume oxygen in cellular respiration, using the energy stored in glucose to make ATP

  40. Sunlight energy • Nearly all the chemical energy that organisms use comes ultimately from sunlight • Energy and chemicals are recycled. Chloroplasts,site of photosynthesis Glucose+O2 CO2+H2O Mitochondriasites of cellularrespiration (for cellular work) Heat energy

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