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Daily Practice 10/13/09. What could you do different this quarter to improve your grade vs. 1 st quarter? What should you do if you miss an assignment? How many days do you have to complete it? Who’s responsibility is it to make up tests/quiz/assignments?

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Daily Practice 10/13/09

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Daily practice 10 13 09

Daily Practice 10/13/09

  • What could you do different this quarter to improve your grade vs. 1st quarter?

  • What should you do if you miss an assignment? How many days do you have to complete it?

  • Who’s responsibility is it to make up tests/quiz/assignments?

  • Turn in any makeup/late work into the tray before the bell rings!!!!!!!!!!!!!!!!!


Ch 2 the chemistry of life

Ch. 2 The Chemistry of Life


Section 6 1

Section 6.1

Atoms, Elements, and Compounds

Objectives

Identify the particles that make up atoms.

Diagram the particles that make up an atom.

Compare covalent bonds and ionic bonds.

Describe van der Waals forces.


Nature of matter

Nature of Matter

  • Chemistry is the study of matter.

  • Atoms – basic unit (building block) of matter

    • 100 million atoms side by side would make a row about 1 cm long (width of a pinkie finger)


Nature of matter1

Nature of Matter

  • Subatomic particles that make up atoms are:

    • Protons – positively charged

    • Neutrons – no charge, same mass as protons

    • Electrons – negative charge and in constant motion surrounding nucleus

  • Nucleus – center of the atom that contains protons and neutrons


Nature of matter2

Nature of Matter

  • Atoms are Neutral

    • Atoms have equal number of electrons and protons

    • Ex: O has 8e- and 8protons

      8e-

      +8p+

      0 charge

    • Atomic Number - # of protons

      in an atom of elements


Elements

Elements

Na

Ca

N

O2

S

Ne

Fe

  • Element – pure substance that consists entirely of one type of atom

    • More than 100 elements are known

    • 24 are commonly found in living organisms

    • 92 of which occur naturally.


Elements1

Elements

  • Each element has a unique name and symbol.

  • Usually 1 letter capitalized like C for carbon

  • Some have 2 letters in this case the second is lower case like in Ca for Calcium


Daily practice 10 13 09

  • The periodic table is organized into:

    • horizontal rows, called periods

    • vertical columns, called groups.


Daily practice 10 13 09

Each individual block in the grid represents an element.

The table is called periodic because elements in the same group have similar chemical and physical properties.


Daily practice 10 14 09

Daily Practice 10/14/09

  • What does the atomic number tell you?

  • What two subatomic particles must be equal in a cell in order for it to be neutral?

  • What does the atomic mass tell you?

  • How do you calculate the number of neutrons?

  • Just like yesterday find the Atomic #, mass, number of neutrons, and make the electron configuration for Cu


Isotopes

Isotopes

  • Isotopes – atoms of same element that differ in number of neutrons they contain

    • Isotopes are identified by mass number

    • Mass Number – sum of protons and neutrons in nucleus of an atom


Isotopes1

Isotopes

  • Isotopes –

    • Protium-1p and mass 1

    • Deutrium-1p and 1neutron and mass 2

    • Tritium – 1p and 2 neutrons and mass 3

  • Isotopes have the same number of e-, all isotopes of elements have the same chemical properties


Radioactive isotopes

Radioactive Isotopes

  • Nuclei are unstable and break down at a constant rate over time.

  • Uses

    • Determine ages of rocks and fossils

    • Treat cancer and kill bacteria that causes food to spoil

    • Used as tracers to follow movements of substances with in organisms


Daily practice 10 13 09

When a nucleus breaks apart, it gives off radiation that can be detected and used for many applications


Daily practice 10 13 09

COMPOUNDS

  • A pure substance formed when two or more different elements combine

  • Compounds are always formed from a specific combination of elements in a fixed ratio.

  • Compounds cannot be broken down into simpler compounds or elements by physical means.

H2O → 2:1→ 2:H and 1:O

NaCl → 1:1 → 1:Na and 1:Cl


Chemical bonds

Chemical Bonds

  • Ionic Bonds – formed when one or more e- are transferred from one atom to another.

  • That means there is an electrical attraction between two oppositely charged atoms or groups of atoms

    • Ion – positively and negatively charged atoms

    • Na Cl


Daily practice 10 13 09

  • Some atoms tend to donate or accept electrons more easily than other atoms.

  • The elements identified as metals tend to donate electrons.

  • The elements identified as nonmetals tend to accept electrons.

  • Most ionic compounds are crystalline at room temperature and have higher melting points than molecular compounds formed by covalent bonds.


Chemical bonds conti

Chemical Bonds Conti.

  • Covalent Bond – formed when e- are shared between atoms.

    • Atoms share 2e- = single covalent bond

      • H2O


Chemical bonds conti1

Chemical Bonds Conti.

  • Atoms share 4e- = double covalent bond

    • O2

  • Atoms share 6e- = triple covalent bond

    • N2

  • Molecule – is a compound that is held together with covalent bonds.

  • Diatomic Molecules – molecules are made of 2 of the same atoms

    • H2, O2, N2, F2,Cl2 , Br2, I2


  • Chemical bonds conti pg 155

    Chemical Bonds Conti. Pg 155

    • Van der Waals Forces – slight attraction that develops between oppositely charged regions of nearby molecules.

      • Van der Waals forces are not as strong as ionic or covalent bonds, they can hold molecules together, especially when molecules are large.

      • The strength of the attraction depends on the size of the molecule, its shape, and its ability to attract electrons.


    Section 6 2

    Section 6.2

    Chemical Reactions

    Objectives

    Identify the parts of a chemical reaction.

    Relate energy changes to chemical reactions.

    Summarize the importance of enzymes in living organisms.


    Chemical reactions and enzymes

    Chemical Reactions and Enzymes

    • Chemical Reaction – process that changes one set of chemicals into another set of chemicals. (That is they are reorganized into different substances)

      • Ex: Fe + O2 → FeO2 (rust – slow process)

      • Ex: 2H2O → H2 + O2


    Chemical reactions and enzymes1

    Chemical Reactions and Enzymes

    • Clues that a chemical reaction has taken place include the production of heat or light, color change and formation of a gas, liquid, or solid.


    Chemical reactions and enzymes2

    Chemical Reactions and Enzymes

    • Reactant – elements or compounds that enter into chemical reaction

      • Ex: Fe + O2 and 2H2O

    • Product – elements or compounds produced by chemical reaction

      • Ex: FeO2 and H2 + O2

      • Lab Demo – Baking Soda


    Daily practice 10 13 09

    Balanced Equations

    • The law of conservation of mass states matter cannot be created or destroyed.

    • The number of atoms of each element on the reactant side must equal the number of atoms of the same element on the product side.


    Energy in reactions

    Energy in Reactions

    • Energy is released or absorbed when chemical bonds form or break

    • Chemical reactions releasing energy occur spontaneously

      • 2H2 + O2 → 2H2O

      • H gas burning with O2 = water vapor with energy released in form of heat and if H explodes = light and sound

      • Humans release energy needed to grow, breathe, think, metabolize, break down food, or digest food


    Energy in reactions1

    Energy in Reactions

    • Chemical Reactions absorbing energy will not occur without source of energy

      • 2H2O → H2 + O2

      • Absorbs energy and must have electric current going through water

      • Plants get energy by trapping and storing energy from the sun

      • Animals get energy when they eat plants or animals that eat plants

    • Activation Energy – energy needed to get reaction started

      • Lighting a match to burn trash


    Energy in reactions2

    Energy in Reactions

    • Activation Energy – energy needed to get reaction started

      • Lighting a match to burn trash


    Energy in reactions3

    Energy in Reactions

    • This reaction is exothermic and released heat energy.

    • The energy of the product is lower than the energy of the reactants.


    Energy in reactions4

    Energy in Reactions

    • This reaction is endothermic and absorbed heat energy.

    • The energy of the products is higher than the energy of the reactants.


    Enzymes

    Enzymes

    • Catalyst – substance that speeds up rate of chemical reaction or lowers reaction’s activation level

      • It does not increase how much product is made.

      • A catalyst is not used up in a reaction.


    Enzymes cont

    Enzymes Cont.

    • Enzymes – proteins that act as biological catalysts

      • Cells use enzymes to speed up chemical reactions that take place in cells and lowers activation energy

      • P. 51 graph

      • Carbonic anhydrase, enzyme in bloodstream that speeds up reaction to remove CO2 (Carbon Dioxide) from blood


    Enzyme action

    Enzyme Action

    • For chemical reactions to occur then reactants must collide with energy so bonds will be broken and new bonds formed

    • The reactants that bind to the enzyme are called substrates – (they help catalyzed reactants)

      • Substrates (protein) that attach to enzyme at active site and form an enzyme – substrate complex


    Enzyme action1

    Enzyme Action

    • The specific location where a substrate binds on an enzyme is called the active site.

    • Proteins have a specific shape, so an active site must be complementary

    • Compared to a lock and key model


    Daily practice 10 13 09

    • The active site changes shape and forms the enzyme-substrate complex, which helps chemical bonds in the reactants to be broken and new bonds to form.


    Enzyme action2

    Enzyme Action

    • When complex is formed, enzyme helps convert substrate into product until done and then they are released

    • Most cells contain proteins that turn key enzymes on or off, along with pH and temperature

      • Human cells work best at 37⁰, human body’s core temperature


    Section 6 3

    Section 6.3

    Water and Solutions

    Objectives

    Evaluate how the structure of water makes it a good solvent.

    Compare and Contrast solutions and suspensions.

    Describe the difference between acids and bases.


    Properties of water

    Properties of Water

    • Water

      • Covers ¾ of Earth

      • Single most abundant compound in most living things

      • Expands as it freezes and is less dense than liquid water explaining why it floats


    Properties of water conti

    Properties of Water Conti.

    • Water Molecules

      • H2O = 2protons H + 8protons O = 10 protons

        2e- H + 8e- = 10e-

        10protons + 10 e- = 0 (neutral)

    • Polarity

      • Water molecule is polar because there is uneven distribution of e- between H and O2 atoms/

        • Between molecules is a magnet with poles

        • O2 end has negative charge and H end has + charge


    Hydrogen bonds

    Hydrogen Bonds

    • A hydrogen bond is a weak interaction involving a hydrogen atom and a fluorine, oxygen, or nitrogen atom

    • Cohesion – attraction b/w molecules of same substance

      • Water molecules can have up to 4 H bonds at the same time

      • Cohesion is why drops of water form beads on smooth surfaces


    Hydrogen bonds1

    Hydrogen Bonds

    • Adhesion – attraction b/w molecules of different substances

      • Water in graduated cylinder dips at center b/c adhesion b/w glass and water molecules are stronger than cohesion of water molecules

      • Capillary action – forces draws water out of plant rot up to stems and leaves


    Solutions and suspensions

    Solutions and Suspensions

    • Mixture – material composed of 2 or more elements or compounds that are physically mixed together but not chemically combined.

      • Ex: vegetable soup, salt and pepper, Earth’s atmosphere gases


    Daily practice 10 13 09

    Homogenous Mixtures

    • A mixture that has a uniform composition throughout

    • A solvent is a substance in which another substance is dissolved.

    • A solute is the substance that is dissolved in the solvent.

    Food coloring dissolved in

    water forms a homogenous

    mixture.


    Daily practice 10 13 09

    Heterogeneous Mixtures

    • In a heterogeneous mixture, the components remain distinct.

    A salad is a heterogeneous mixture.


    Solutions and suspensions conti

    Solutions and Suspensions Conti.

    • 2 types of mixtures made with water are solution and suspensions.

      • Solution (sol’n) – mixture of 2 or more substances where the molecules of substance are evenly distributed

        • Ex: table salt put into water

      • Solute – substance that is dissolved (table salt)

      • Solvent – substance where the solute dissolves (water)


    Solutions and suspensions conti1

    Solutions and Suspensions Conti.

    • Suspensions – mixture of water and non-dissolved material

      • Ex: blood is mostly water with many dissolved compounds)


    Acids bases ph p 164

    Acids, Bases, pH - P. 164

    • pH scale – measurement system used to indicate the concentration of Hydrogen ions (H+) in solution

      • 07 14

    • Acids – Substances that release hydrogen ions (H+) when dissolved in water

      • 0 6.9 = acid

      • The lower the number the stronger the acid


    Acids bases ph p 1641

    Acids, Bases, pH - P. 164

    • Bases Substances that release hydroxide ions (OH–) when dissolved in water

      • 7.1 14 = base

      • The higher the number the stronger the base

    • Buffers –are mixtures that can react with acids or bases to keep the pH within a particular range.

      • Fluids in human cells is 6.5 -7.5 to maintain homeostasis.


    Section 6 4

    Section 6.4

    The Building Blocks of Life

    Objectives

    Describe the role of carbon in living organisms.

    Summarize the four major families of biological macromolecules.

    Compare the functions of each group of biological macromolecules.


    Carbon compounds

    Carbon Compounds

    C

    • Organic Chemistry – study of all compounds that contain bonds between C atoms

    • Chemistry of Carbon (C)

      • C atoms have 4 valence e-

      • C’s atomic # is 6 (2e- in 1st shell, 4e- in 2nd shell)

      • Each e- can join with e- from another atom forming strong covalent bonds

      • C can bond with H, O, P, S, N

    • C has the ability to form millions of different large and complex structures


    Carbon compounds cont

    Carbon Compounds Cont.

    C

    • One carbon atom can form four covalent bonds with other atoms.

    • Carbon compounds can be in the shape of straight chains, branched chains, and rings.


    Carbon compounds conti

    Carbon Compounds Conti.

    • Macromolecules – giant molecules

      • Monomers – small unit that can join together with other small units to form polymers

      • Polymers – large compound formed from combo of many monomers

      • Monomers can be identical like metal links in watch bands or different beads in multicolored necklace.

      • 4 groups of organic compounds found in living things carbohydrates, lipids, nucleic acids, proteins


    Carbon compounds conti1

    Carbon Compounds Conti.

    • Carbohydrates (Carbs) –Compounds composed of carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom; a ratio 1:2:1—(CH2O)n

      • Living things use carbs as main source of energy

      • Starches and sugars are carbs used as an energy source

      • Plants and some animals use carbs

      • for structural purposes.


    Daily practice 10 13 09

    • Values of n ranging from three to seven are called simple sugars, or monosaccharides.


    Carbon compounds conti2

    Carbon Compounds Conti.

    • Monosaccharides – single sugar molecules

      • Ex: Galactose – in milk and Fructose – in fruit

  • Polysaccharides – large macromolecules formed from monosaccharides

    • Glucose in blood runs low, glycogen is released from your liver.

    • Glycogen – stored in muscles and supplies energy for muscle movement

    • Plants use cellulose that gives them strength and rigidity

      • Major component of wood and paper


  • Carbon compounds conti3

    Carbon Compounds Conti.

    • Lipids – macromolecules made from C and H atoms, including fats, oils, and waxes

      • Store energy

      • Important parts of biological membranes and waterproof coverings

      • Steroids are chemical messengers of lipids

      • A triglyceride is a fat if it is solid at room temperature and an oil if it is liquid at room temperature


    Daily practice 10 13 09

    • Lipids that have tail chains with only single bonds between the carbon atoms are called saturated fats.

    • Lipids that have at least one double bond between carbon atoms in the tail chain are called unsaturated fats.

    • Fats with more than one double bond in the tail are called polyunsaturated fats.


    Carbon compounds conti4

    Carbon Compounds Conti.

    • Proteins – macromolecules containing N,C, H, O

      • Proteins have specific roles

        • Control rate of reaction and regulate cell processes

        • Form bones and muscles

        • Transport substances into and out of cells to fight disease


    Carbon compounds conti5

    Carbon Compounds Conti.

    • Proteins are polymers of amino acids

      • Amino acids – are small compounds that are made of carbon, nitrogen, oxygen, hydrogen, and sometimes sulfur.

      • 20 amino acids are found in nature & all may be joined together by covalent bonds

      • Amino acids are monomers of proteins

      • Amino acids have a central carbon atom.

      • One of the four carbon bonds is with hydrogen.

      • The other three bonds are with an amino group (–NH2), a carboxyl group (–COOH), and a variable group (–R).


    Daily practice 10 13 09

    • The number and the order in which the amino acids are joined define the protein’s primary structure.

    • After an amino acid chain is formed, it folds into a unique three-dimensional shape, which is the protein’s secondary structure, such as a helix or a pleat.


    Carbon compounds conti6

    Carbon Compounds Conti.

    • Nucleic Acids – macromolecules containing H, O, N, C, P

      • Nucleotides – 5-Carbon sugar, phosphate group, and nitrogenous base

      • Nucleic Acids store and transmit hereditary or genetic information

        • 2 types – ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)

      • Nucleic acids are made of smaller repeating subunits called nucleotides, composed of carbon, nitrogen, oxygen, phosphorus, and hydrogen atoms.


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