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CHEMISTRY

Atoms:

Matter is made up of atoms

Atoms join together to from chemicals

Proton= positive charge, 1 mass unit

Neutron= neutral, 1 mass unit

Electron= negative charge, low mass

Atomic Structure

  • Atomic number= number of protons

  • Mass number= number of protons plus neutrons

  • Nucleus contains protons and neutrons

  • Electron cloud contains protons

    neutrons= atomic mass - atomic

Elements- determined by atomic number of atoms

  • Atomic number= number of protons

Isotopes- a version of an element based on its mass number

  • Mass number= number of protons plus the number of neutrons

  • Only neutrons are different because number of protons determines the element

Atomic Weights= Average of the mass numbers of the isotopes

Electrons and Energy Levels

Electrons determine the reactivity of an atom

The electron cloud contains shells, or energy levels that hold a maximum number of electrons

  • Lower shells first

  • Outermost shell is the valence shell, and it determines bonding

  • The number of electrons per shell corresponds to the number of atoms in that row of the periodic table

Bonds:

Ionic Bonds

  • One atom loses one or more electrons and becomes a cation, with a positive charge

  • Another atom gains those same electron and becomes an anion, with a negative charge

  • Attraction between the opposite charges then draws the two ions together

Covalent Bonds- the sharing of pairs of electrons between atoms

One electron is donated by each atom to make the pair of electrons

Sharing one pair of electrons is a single covalent bond

  • sharing two pairs= double covalent bond

  • sharing three pairs= triple covalent bond

Nonpolar covalent bonds- equal sharing of electrons because of equal pull for the electrons

Polar covalent bonds- unequal sharing of electrons because one atom has a disproportionately strong pull on the electrons forming polar molecules- like water

Hydrogen Bonds are bonds between adjacent molecules, not atoms

Involve slightly positive and slightly negative portions of polar molecules being attracted to one another

Hydrogen bonds between H2O molecules cause surface tension

Importance of Water:

water- two-thirds of total body weight

solubility- water’s ability to dissolve a solute in a solvent to make a solution

reactivity- most body chemistry occurs in water

high heat capacity- water’s ability to absorb and retain heat

lubrication- to moisten and reduce friction

pH- concentration of hydrogen ion (H+) in a solution

Neutral pH is a balance of H+ and OH-

  • pure water=7.0

pH of human blood ranges from 7.35 to 7.45

Acidic- pH lower than 7.0

basic (or alkaline)- pH higher than 7.0

pH Scale- more than H+ ions mean lower pH, less H+ ions mean higher pH

Organic Molecules:

Contain H, C, and usually O

Covalently bonded

Carbohydrates

Carbohydrates contain carbon, hydrogen, and oxygen ina 1:2:1 ratio

Monosaccharides

Simple sugars with 3 to 7 carbon atoms

Glucose, fructose, galactose= C6H12O6

  • glucose= sugar in blood

  • fructose= fruits

  • galactose= milk

Disaccharides

Two simple sugars condensed by dehydration synthesis

Sucrose, maltose, lactose= C12H22O11

Sucrose- table sugar (sugar cane)

  • glucose + fructose= sucrose

maltose- malt sugar (from grains)

  • glucose + glucose= maltose

lactose- milk

Polysaccharides

Glucose molecules condensed by dehydration synthesis

Glycogen, starch, cellulose

  • glycogen- stored animal starch in liver + muscles

  • starch- food for embryonic seed or to store glucose

  • cellulose- plant cell walls + provides fiber

Lipids:

Mainly hydrophobic molecules such as fats, oils, and waxes

Made mostly of carbon and hydrogen atoms

Fatty Acids

Long chains of a carbon and hydrogen with a carboxylic acid group (COOH) at one one end

Fatty acids may be

  • Saturated with hydrogen (no double covalent bonds)

  • Unsaturated (one or more double bonds):

  1. monounsaturated= one double bond

  2. polyunsaturated= two or more double bond

Prostaglandins- local hormones, short- chain fatty acids

Triglycerides- three fatty-acid tails attached to a glycerol molecule

  • Functions: energy source, insulation, protection

Steroids

  • Four rings of carbon and hydrogen with an assortment of functional groups

  • Types of steroids:

  1. Cholesterol is a component of plasma (cell) membrane

  2. Estrogens and testosterone are sex hormones

  3. Corticosteroids and calcitriol function in metabolic regulation

  4. Bile salts are derived from steroids

Phospholipids

  • a fatty acid, a phosphate group & a glycerol molecules

  • components of plasma (cell) membranes

Proteins most abundant and important organic molecules

Contain basic elements CHON

Basic building blocks are 20 amino acids

List seven major protein functions:

  • Coordination + Control

    • hormones ex. adrenaline

  • Defense

    • antibodies

      • identify bacteria/ viruses then alert white blood cells

  • Support

    • structural proteins

      • keratin(hair/nails) + collagen(nail)

  • Movement

    • contractile proteins

      • actin(act thin) + myosin(me me me)

  • Transport

    • transport(carrier) proteins

      • hemoglobin

  • Buffering

    • regulation of pH

  • Metabolic Regulation

    • enzymes ex. sucrase, lactase

Lipids provide 2x more energy than protein

Anything w/ nitrogen is probably protein

Protein structure= long chains of amino acids

Amino Acid Structure-

  • central carbon atom

  • hydrogen atom

  • amino group(-NH2)

  • carboxylic acid group(-COOH)

  • variable side chain or “R” group

Enzymes=catalysts

  • Proteins lower the activation energy of a chemical reaction, are not changed or used up in the reaction, and are specific- will only work on limited types of substrates

Denaturation= change in shape due to heat or pH

Nucleic acids store + process information at the molecular level

  • Deoxyribonucleic Acid (DNA) determines inherited characteristics, directs protein synthesis, controls enzyme production, and controls metabolism

  • Ribonucleic Acid (RNA) controls intermediate steps in protein synthesis

Structure of Nucleotides:

  • a sugar(deoxyribose or ribose)

  • phosphate group

  • nitrogenous base (A,G, T, C, or U)

DNA= double stranded, and the bases form hydrogen bonds to hold the DNA together

RNA usually a single strand

DNA forms a twisting double helix

Purines pair with pyrimidines

  • DNA:

    • adenine(A) and thymine(T)

    • cytosine(C) and guanine(G)

  • RNA:

    • uracil(U) replaces thymine(T)

Types of RNA:

  • messenger RNA (mRNA)

  • transfer RNA (tRNA)

  • ribosomal RNA (rRNA)

Nucleotides can store energy

  • Adenosine diphosphate (ADP) di-=2

  • Adenosine triphosphate (ATP) tri-=3

Adding a phosphate group to ADP with a high-energy bond to form a high-energy compound

Red blood cells don’t have a nucleusc

Atoms:

Matter is made up of atoms

Atoms join together to from chemicals

Proton= positive charge, 1 mass unit

Neutron= neutral, 1 mass unit

Electron= negative charge, low mass

Atomic Structure

  • Atomic number= number of protons

  • Mass number= number of protons plus neutrons

  • Nucleus contains protons and neutrons

  • Electron cloud contains protons

    neutrons= atomic mass - atomic

Elements- determined by atomic number of atoms

  • Atomic number= number of protons

Isotopes- a version of an element based on its mass number

  • Mass number= number of protons plus the number of neutrons

  • Only neutrons are different because number of protons determines the element

Atomic Weights= Average of the mass numbers of the isotopes

Electrons and Energy Levels

Electrons determine the reactivity of an atom

The electron cloud contains shells, or energy levels that hold a maximum number of electrons

  • Lower shells first

  • Outermost shell is the valence shell, and it determines bonding

  • The number of electrons per shell corresponds to the number of atoms in that row of the periodic table

Bonds:

Ionic Bonds

  • One atom loses one or more electrons and becomes a cation, with a positive charge

  • Another atom gains those same electron and becomes an anion, with a negative charge

  • Attraction between the opposite charges then draws the two ions together

Covalent Bonds- the sharing of pairs of electrons between atoms

One electron is donated by each atom to make the pair of electrons

Sharing one pair of electrons is a single covalent bond

  • sharing two pairs= double covalent bond

  • sharing three pairs= triple covalent bond

Nonpolar covalent bonds- equal sharing of electrons because of equal pull for the electrons

Polar covalent bonds- unequal sharing of electrons because one atom has a disproportionately strong pull on the electrons forming polar molecules- like water

Hydrogen Bonds are bonds between adjacent molecules, not atoms

Involve slightly positive and slightly negative portions of polar molecules being attracted to one another

Hydrogen bonds between H2O molecules cause surface tension

Importance of Water:

water- two-thirds of total body weight

solubility- water’s ability to dissolve a solute in a solvent to make a solution

reactivity- most body chemistry occurs in water

high heat capacity- water’s ability to absorb and retain heat

lubrication- to moisten and reduce friction

pH- concentration of hydrogen ion (H+) in a solution

Neutral pH is a balance of H+ and OH-

  • pure water=7.0

pH of human blood ranges from 7.35 to 7.45

Acidic- pH lower than 7.0

basic (or alkaline)- pH higher than 7.0

pH Scale- more than H+ ions mean lower pH, less H+ ions mean higher pH

Organic Molecules:

Contain H, C, and usually O

Covalently bonded

Carbohydrates

Carbohydrates contain carbon, hydrogen, and oxygen ina 1:2:1 ratio

Monosaccharides

Simple sugars with 3 to 7 carbon atoms

Glucose, fructose, galactose= C6H12O6

  • glucose= sugar in blood

  • fructose= fruits

  • galactose= milk

Disaccharides

Two simple sugars condensed by dehydration synthesis

Sucrose, maltose, lactose= C12H22O11

Sucrose- table sugar (sugar cane)

  • glucose + fructose= sucrose

maltose- malt sugar (from grains)

  • glucose + glucose= maltose

lactose- milk

Polysaccharides

Glucose molecules condensed by dehydration synthesis

Glycogen, starch, cellulose

  • glycogen- stored animal starch in liver + muscles

  • starch- food for embryonic seed or to store glucose

  • cellulose- plant cell walls + provides fiber

Lipids:

Mainly hydrophobic molecules such as fats, oils, and waxes

Made mostly of carbon and hydrogen atoms

Fatty Acids

Long chains of a carbon and hydrogen with a carboxylic acid group (COOH) at one one end

Fatty acids may be

  • Saturated with hydrogen (no double covalent bonds)

  • Unsaturated (one or more double bonds):

  1. monounsaturated= one double bond

  2. polyunsaturated= two or more double bond

Prostaglandins- local hormones, short- chain fatty acids

Triglycerides- three fatty-acid tails attached to a glycerol molecule

  • Functions: energy source, insulation, protection

Steroids

  • Four rings of carbon and hydrogen with an assortment of functional groups

  • Types of steroids:

  1. Cholesterol is a component of plasma (cell) membrane

  2. Estrogens and testosterone are sex hormones

  3. Corticosteroids and calcitriol function in metabolic regulation

  4. Bile salts are derived from steroids

Phospholipids

  • a fatty acid, a phosphate group & a glycerol molecules

  • components of plasma (cell) membranes

Proteins most abundant and important organic molecules

Contain basic elements CHON

Basic building blocks are 20 amino acids

List seven major protein functions:

  • Coordination + Control

    • hormones ex. adrenaline

  • Defense

    • antibodies

      • identify bacteria/ viruses then alert white blood cells

  • Support

    • structural proteins

      • keratin(hair/nails) + collagen(nail)

  • Movement

    • contractile proteins

      • actin(act thin) + myosin(me me me)

  • Transport

    • transport(carrier) proteins

      • hemoglobin

  • Buffering

    • regulation of pH

  • Metabolic Regulation

    • enzymes ex. sucrase, lactase

Lipids provide 2x more energy than protein

Anything w/ nitrogen is probably protein

Protein structure= long chains of amino acids

Amino Acid Structure-

  • central carbon atom

  • hydrogen atom

  • amino group(-NH2)

  • carboxylic acid group(-COOH)

  • variable side chain or “R” group

Enzymes=catalysts

  • Proteins lower the activation energy of a chemical reaction, are not changed or used up in the reaction, and are specific- will only work on limited types of substrates

Denaturation= change in shape due to heat or pH

Nucleic acids store + process information at the molecular level

  • Deoxyribonucleic Acid (DNA) determines inherited characteristics, directs protein synthesis, controls enzyme production, and controls metabolism

  • Ribonucleic Acid (RNA) controls intermediate steps in protein synthesis

Structure of Nucleotides:

  • a sugar(deoxyribose or ribose)

  • phosphate group

  • nitrogenous base (A,G, T, C, or U)

DNA= double stranded, and the bases form hydrogen bonds to hold the DNA together

RNA usually a single strand

DNA forms a twisting double helix

Purines pair with pyrimidines

  • DNA:

    • adenine(A) and thymine(T)

    • cytosine(C) and guanine(G)

  • RNA:

    • uracil(U) replaces thymine(T)

Types of RNA:

  • messenger RNA (mRNA)

  • transfer RNA (tRNA)

  • ribosomal RNA (rRNA)

Nucleotides can store energy

  • Adenosine diphosphate (ADP) di-=2

  • Adenosine triphosphate (ATP) tri-=3

Adding a phosphate group to ADP with a high-energy bond to form a high-energy compound

Red blood cells don’t have a nucleusc