2ChemistryElement - A substance that can not be broken down into simpler substance.Trace elements are found in living things in very small amounts.Ex. Iron, Zinc, Flourine, Iodine
3Atom - the smallest particle of an element that has the characteristics of that element. Proton – (+) in nucleusNeutron – (no charge) in nucleusElectron – Forms cloud around nucleus
4Electron energy levels The electron travels around the nucleus in certain regions called energy levels.1st level – holds two electrons2nd level – holds eight electrons3rd level – holds eighteen electrons
5Definitions Element name – How do the get them? Chemical symbol - The one or two letter symbol.Atomic number - The whole number in every square.Mass number: The number with a decimal fraction in most squares
6Number of protons in atom: Always equal to the atomic number. Number of electrons in atom: Equal to the atomic number in a normal atom.Number of neutrons in atom: Subtract the atomic number from the mass number to find the number of neutrons.
7IsotopesAtoms of the same element that have different numbers of neutrons are called isotopesEx. Carbon-12, Carbon-13, Carbon-14Radiation can kill cells, and are used by scientists to kill rapidly growing cancer
8Compounds and BondingA compound is a substance that is composed of atoms of two or more different elements that are chemically combined.Two types of bonds are:Ionic BondsCovalent Bonds
9Chemical ReactionsWhen chemicals reactions occur, bonds between atoms are broken or formed, causing substances to recombine as different molecules.All the chemical reactions that occur within an organism are referred to as the organism’s metabolism.
10Writing Chemical Equations 2C12H22O11The subscript number in a formula indicate the number of atoms of each element in molecule of the substance.The number in front of the chemical formula tells us the number of molecules of each substance.
11SolutionA solution is a mixture in which one or more substances (solutes) are distributed evenly in another substance (solvent).Ex. Kool-AidMixtureA mixture is a combination of substances in which the individual components retain their own properties.Ex. Sand and sugar
12Acids and Bases pH is a measure of how acidic or basic a solution is. A scale with values of 0-14 are used.Acid - Forms H+ ions and has a pH below 7Base - Forms OH- ions has a pH above a 7
14Water and Its Importance 1. Water is polar2. It resists temperature changes3. It expands when it freezes.Polar Molecule – A molecule with an unequal distribution of charge, resulting in the molecule having a pos. end and a neg. endBrownian Motion Robert Brown used a microscope to observe pollen grains suspended in water
15DiffusionDiffusion is the net movement of particles from an area of high concentration to an area of lower concentration.Three key factors, concentration, temperature, and pressure affect the rate of diffusion.Dynamic Equilibrium – result of diffusion where there is continuous movement of particles but no overall change in concentration.
16Life SubstancesRole of Carbon - A carbon atom has four electrons available for bonding in its outer energy level.Molecular chains - Cells build macromolecules in organisms by bonding small molecules together to form chains called polymers.
17Main organic substances Carbohydrates - The simplest Carbo is simple sugar – MonosaccharideLipids - Lipids are commonly known as FATS and OILS.Proteins - The basic building blocks of proteins is AMINO ACIDS.Nucleic Acids - A nucleic acid is a complex macromolecule that stores cellular information in the form of a code.
19Development of Light Microscope Anton van Leeuwenhoek was the first scientist to describe living cells as seen through a simple microscope.Simple Light Microscope - One lens and uses natural lightCompound Light Microscope - More than one lens to magnify.Magnifies up to 1500 times.
21Cell TheoryRobert Hooke used a Compound Light Microscope to study CORK.Cells are the basic building blocks of all living things.
22The Cell Theory - Three main ideas All organisms are composed of one or more cellsThe cell is the basic unit of organization of organisms.All cells come from preexisting cells.
23Types of Electron Microscopes Scanning Electron Microscopes (SEM) - Used to scan the surface of cells to learn their 3-dimensional shapeTransmission Electron Microscope (TEM) - Used to study the structures contained within the cell.
25Two Basic Cell TypesProkaryotes - Cells Lacking internal membrane-bound organellesContains the followingPlasma membraneRibosomesChromosomeEukaryotes - Cells containing membrane-bound organellesIncludes all of the organelles.
26ProkaryotesProkaryotic cells are small, simple and primitive. They were the first type of cells to appear on Earth. Fossil evidence shows ancient prokaryotes 3.5 billion years old.Eukaryotic cells evolved from the prokaryotes about 1.5 billion years ago. They are larger in size and more advanced and complex.
27Functions of the Plasma Membrane Selective Permeability – feature of the plasma membrane that maintains homeostasis within a cell by allowing some molecules into the cell while keeping other out.Plasma Membrane – Controls materials such as water and nutrients in and out of a cell.
28Plasma membrane (also called the cell membrane) StructureThe plasma membrane is composed of Phosolipid Bilayer, biological molecules that have a phosphate group at the head and two fatty acid chains hanging down as tails.Heads – HydrophilicFatty acid chain tail - Hydophobic
31ProteinsIntegral Proteins are located in membrane interior, associated with lipids, insoluble, released only by agents which disrupt the membrane bilayer.Peripherial Proteins are located on membrane surfaces; soluble, not associated with lipids, released by treatments which leave the bilayer completely intact
34Cell StructuresNucleus - Within the nucleus is the DNA (Chromatin) responsible for providing the cell with its unique characteristics.Nucleolus - the prominent structure in the nucleus which produces ribosomes.Ribosomes - produce protein and take the RNA message from the ER and turn it into protein
35Cytoplasm - supports the organelles and provides a solvent in which chemical reactions can proceed and consists of the cellular contents held inside the plasma membrane.The cytoplasm is the "guts" of a cell.Cell Wall - A fairly rigid structure located outside the plasma membrane and provides additional support and protection to the cell.
36Endoplasmic Reticulum (ER) - transport materials from the nucleus to other organelles within the cytoplasm.connecting tunnels for the transportation of cellular moleculesRNA messagesThere are two kinds of ER, distinguished by the presence or absence of ribosomesSmooth ER - transports non-protein materials, such as lipids (no ribosomes)Rough ER - is dotted with ribosomes, the site of protein translation
38Golgi Bodies (Function) - It lies serves to receive, modify, and transport the newly synthesized proteins (Structure) - the Golgi is a continuation of the membrane structure of the ER. Consists of a stack of flat membrane diskVacuole - simply an empty space that is surrounded by a single membrane. Some store water, other food, still others store waste.Lysosomes - (common in animal cells but rare in plant cells) contain digestive enzymes.
40Peroxisomes - responsible for protecting the cell from its own production of toxic hydrogen peroxide Chloroplasts - specialized organelles found in all higher plant cells. These organelles contain the plant cell's chlorophyll, hence provide the green color.Mitochondria -provide the energy a cell needs to move, divide, produce secretory products, contract - in short, they are the power centers of the cell
42The cytoskeleton is divided into two components: Cytoskeleton - composed of tiny rods and filaments that form the framework for the cell (like the skeleton in our bodies)The cytoskeleton is divided into two components:1. The microfilaments are a network of protein strands anchored to the plasma membrane.2. The microtubules play several roles within the cell, including forming the mitotic spindle (about which we'll learn more about later), cilia, and flagella.
43Cilia - Are short, hairlike projections that move like WAVE. Flagella - Are long projections that move with a whip-like motion.
44Cellular TransportOsmosis: the movement of water molecules from an area of high concentration to an area of low concentration through a selectively permeable membrane.Three types of solutions:Hypotonic, Hypertonic, and Isotonic
45Hypertonic Solutions (Animal cells) The concentration of dissolved substances outside the cell is higher than the concentration inside the cellMore water inside the cell than outsideWater diffuses out; shrinking of the cell
46Hypotonic Solutions (Animal cells) The concentration of dissolved substances inside the cell is higher than the concentration outside the cellMore water outside the cell than insideWater diffuses in; exploding of the cell
47Plant cellsHypertonic environment - lose water, mainly from the central vacuole. The plasma membrane and cytoplasm shrink away from the cell wall.Hypotonic environment - Do not burst because of rigid cell wall that supports the cell. The plasma membrane is pressed against the cell wall. Instead of bursting, it becomes firm
48Isotonic Solutionscontain the same concentration of dissolved substances inside the cell as it does outside the cell.When a cell is placed in an isotonic solution, the water diffuses into and out of the cell at the same rate. The fluid that surrounds the body cells is isotonic.
50Passive transportThe movement of particles across the cell membrane by diffusion or osmosis; the cell uses NO energy to move particles across the membraneThe passive transport of materials across the plasma membrane with the aid of transport proteins is called - Facilitated Diffusion
51Active TransportMovement of materials through a membrane against a concentration gradient is called - Active Transport (Requires energy)Two types of Active transport:1. Endocytosis – process by which a cell surrounds and takes in material from the environment2. Exocytosis – the expulsion or secretion of materials from a cell.
52Because endocytosis and exocytosis both move masses of material, they both require energy and are, therefore, both forms of Active Transport.
54Cell Growth and Reproduction Cell Size LimitationsDiffusion limits cell size - Diffusion is fast and efficient process over short distancesDNA limits cell size - But there is a limit as to how quickly the blueprints for these proteins can be copied in the nucleus and made into proteins in the cytoplasm.Surface area-to-volume ratio - As a cell’s size increases, its volume increases much faster than its surface area.
55Cell ReproductionRemember that the Cell Theory states that cells come from preexisting cells.Cell Division is the process by which new cells are produced from one cell.Old cells are shedding and be replaced, New cells are produced in millions just in seconds.
56ChromosomesChromosomes – are structures which contain DNA and become darkly colored when stained.Scientist have learned that chromosomes are the carriers of the genetic material that is copied and passed on from generation to generation of cells.
57For most of the cell’s lifetime, chromosomes exist as Chromatin, long strands of DNA wrapped around proteins.Under the Electron microscope, chromatin looks like a plate of tangled-up spaghetti- However before the cell can divide the long stands of chromatin must be reorganized.
59The cell cycle is the sequence of growth and division of a cell. There are two basic stages in the life cycle of a cell: Interphase (I), during which the cell grows, and Mitosis (M), during which the cell reproduces. The cell cycle alternates between interphase and mitosis
61InterphaseDuring interphase, the cell grows and does not divide. The DNA is separated from the cytoplasm inside the nucleus.Interphase accounts for about 90% of the time of the cell cycle.Interphase is divided into three parts;- G1, S, G2
62G1, S, G2 PhasesG1 Phase – Rapid Growth and metabolic activities (Protein production is high)S Phase – DNA synthesis and replicationG2 Phase – Cell prepares for division. Also other organelles are manufactured such as mitochondria.
63The Phases of MITOSISProphaseMetaphaseAnaphaseTelophase
64Prophase – Longest Phase During prophase the nucleus begins to disappear. The chromatin pulls together and forms pairs of rope-like structures called chromatid pairs.These chromatid pairs are actually identical chromosomes that developed during the S phase of interphase. The chromatid pairs are held together by a structure called the centromere.Spindle fibers also begin to appear and along with the centrioles they migrate to the poles of the cell
66MetaphaseMetaphase begins when the chromatid pairs line up along the center of the cell. This makes it possible for the chromatids to position themselves so that they can migrate to the opposite poles of the cellAnaphase is the stage where this process occurs. The chromatid pairs split and the spindle fibers contract pulling each chromosome toward their pole. This process continues until the chromosomes arrive at each pole. The nucleus reappears and the spindle fibers disappear .
69TelophaseTelophase begins as the chromatids reach the opposite poles and spit into 2 daughter cells, each identical in the number and type of chromosomes. They are smaller than the mother cell and will begin to develop starting interphase again.When the cytoplasm splits this is called cytokinesis.
71Results of MitosisIn multicellular organisms cell growth and reproduction result in groups of cells that work together as TISSUE to perform a specific function.Tissue organize in various combinations to form ORGANS.Multiple organs work together to form an ORGAN SYSTEM.
72Control of Cell CycleEnzymes are necessary to begin and drive the cell cycle.Cancer is the result of uncontrolled cell divisionA Gene is a segment of DNA that controls the production of a protein.
74ATPThe main energy molecule used by living things is ATP: (Adenosine triphosphate)ATP Structure (Draw below)Energy is stored in the bonds between the phosphates – they are special high energy bonds
75(adenosine diphosphate) ATP – ADP cycleThis cycle happens all of the time in the cells of living things. (Finish the drawing)ATP+P PADP(adenosine diphosphate)
76Using new energy to add a phosphate group to ADP to make ATP is called phosphorylation of ADP. Enzymes catalyze these reactions (ATPase breaks down ATP and ATP synthetase makes ATP from ADP)It takes millions of ATP-ADP cycles to keep a human alive each day.The ATP and ADP molecules get reused over and over again. Energy does NOT get reused.
77Sources of New Energy Sun Chlorophyll – containing autotrophs (plants and algae through photosynthesis)Heterotrophs that have eaten autotrophs (animals, protozoa, fungi, and bacteria)Some produce energy from chemicals instead of sun. These autotrophs use a process known as Chemosynthesis.
78Energy Transfer Processes Electron transport chain (ETC) – High energy electrons can be transferred from molecule to molecule –as they move, they give off tiny bits of energy with each transferChemiosmosis – When H+ ions move across membranes in chloroplasts, stored electrochemical energy is released.Coenzymes – Large energy carrier molecules. These are able to transfer energy within the cell bycarring high energy H from place to place
79Common Coenzymes NAD ----- picks up H to become NADH NADP picks up H to become NADPHFAD picks up H to become FADHThese coenzymes often carry hydrogens and their electrons to ETC
80Photosynthesis Meaning “making with light” Photosynthesis is the process of converting sun energy into usable biological energy (the sugar glucose)Photosynthesis takes place in the _________ and ___________ of chloroplasts.The green pigment _____________ is required for photosynthesis.
81Write the basic equation for photosynthesis below: The speed at which photosynthesis occurs is affected by:A.B.C.
82Photosynthesis – 1st Step LIGHT REACTION – Occurs only in the light. Occurs in membranes of thylakoid disks in chloroplasts.Photons of light strike chlorophyll on the leaf.Energy from the light is transferred to electrons in chlorophyll. These “excited” electrons enter an ETC in the chloroplast membrane.Some of these excited electrons in the energized chlorophyll is transferred to the coenzyme NADP+ to make NADPHWater is split and the oxygen part is released from the leaves as a waste product we breathe.
83Photosynthesis – 2nd Step Dark Reaction (aka Calvin cycle)– can occur in the light OR in the dark. Since the energy from the light has already been transferred to NADPH and ATP, the dark reaction can take place an time AFTER the light reaction occurs. This process takes place in the stroma of chloroplasts.CO2 enters the plant through holes in the leaves (stomates).The energy from ATP and NADPH is used to put carbon (from ____) and sugar together to make a 6 carbon sugar called ___________.
84The glucose made by the green plants is used in several ways: 1. Directly as energy for the plant – through cell respiration. This occurs in the mitochondria.2. Stored in long strings as starch – usually roots.3. used to make cellulose for cell walls4. Stored as oils in seeds, stems, leaves
86Alternative pathways Alternative pathways – instead of Calvin cycle C3 pathway is used by most plantsC4 =CAM =
87(long) R O Y G B I V (Short) Wavelengths of LightSeveral different wavelengths of light are used in photosynthesis.Sunlight many because all wavelengths are mixed together, making light appear “white” or clear.Wavelengths of light separate in the following order (according to the length of the light wave)(long) R O Y G B I V (Short)
88When light hits an objects, one of three things can happen: (draw) The color that objects appear to us is the color of light reflected from the object.Green plants reflect green light—they do not use it for energy. They absorb large amounts of Red and Blue light
89Two types of Cell Respiration: Energy stored in glucose is released through a process called Cell respiration. This occurs in all living organisms.Two types of Cell Respiration:Aerobic – requires O2Glycolysis Kreb’s cycle (CAC)ETCAnaerobic – Does not require O2Glycolysis Fermentation
91Kreb’s Cycle (Citric Acid Cycle) – p. 239 Where: __________________________Type:____________________________Reactants:_________________________Products:_________________________
92Electon Transport Chain (ETC) Where: __________________________ Type:____________________________Reactants:_________________________Products:_________________________(FADH2 and NADH2 supply energy to convert ADP to ATP)
94Basic Steps of Anaerobic Cell Respiration (Occurs after glycolysis if O2 is not present)Cells must perform glycolysis to live. Glycolysis will stop if its products cannot go on to aerobic respiration.The products of glycolysis can be recycled through fermentation.Fermentation allows glycolysis to continue in absence of O2Even though there is no net gain of ATP from fermentation, cells must do it in anaerobic conditions in order to keep functioning.
95Pyruvic Acid + NADH2 lactic acid + NAD (recycled back to glycolysis) Fermentation - 2 TypesLactic Acid Fermentation (in animals and some bacteria)Pyruvic Acid + NADH2 lactic acid + NAD (recycled back to glycolysis)Alcoholic Fermentation (yeasts, plants)Pyruvic Acid + NADH2 alcohol + CO2 + NAD
96Practical Applications Lactic Acid fermentationBacteria in a closed container of milk are in anaerobic conditions. Forced into fermentation they produce lactic acid. Lactic acid curdles milk. It also produces cheese, yogurt, sour cream, and cottage cheese.Alcoholic Fermentation1. Yeasts in bread dough = anaerobic conditions. CO2 gas makes dough rise. Alcohol evaporates out of bread during baking.
97Energy Summary (number of ATP molecules formed in each step of respiration) Glycolysis4 (net = 2)ATPKreb’s cycle2 ATPElectron Transport32 ATPTotal: Aerobic Respiration38 ATP (net = 36)Glycolysis4 (net = 2)ATPFermentation0 ATPTotal: Anaerobic Respiration2 ATP