BIOCHEMISTRY

Matter

Anything that has mass and occupies space

Some matter is changed chemically to produce energy

Energy used to carry out cell activities

Properties of Matter

Exists in 3 statesSolid – definite volume, definite

shapeLiquid – definite volume, indefinite

shapeGas – indefinite volume, indefinite

shape

Properties of Matter

Chemical and Physical Properties Physical Properties – physical appearance or

characteristic of a substance Color Boiling or Melting Point Hardness

Chemical Properties – how one kind of matter reacts with other matter Burning of a substance

Properties of Matter

Physical and Chemical Changes Physical Changes – appearance changes, matter

does not Change of State

Freezing – from liquid to solid Melting – from solid to liquid Evaporation – from liquid to gas Condensation – from gas to liquid Sublimation – from solid to gas

Change in size – cutting paper Chemical Change – matter changes

Iron reacts with oxygen to produce rust Law of Conservation of Matter – matter is neither

created nor destroyed, only changes form

Atoms and Elements

Atom – tiny unit of matter Composed of:

Protons - + charge, 1amu, in nucleus Neutron – no charge, 1amu, in nucleus Electron - - charge, 0 amu, in electron cloud

Atoms and Elements

Element – Substance containing only one type of atom Atoms of same elements have the same

number of protons – called Atomic Number Hydrogen – 1 proton Oxygen – 8 protons

Sum of protons + neutrons determines Atomic Mass Number

Isotopes – atoms that have the same number of protons but different numbers of neutrons

Number of electrons = Number of protons; result atom is electrically neutral

Atoms and Elements

Elements are arranged according to atomic number in the Periodic Table

Atoms and Elements

Element Symbols1st one or two letters of English name

Hydrogen - HHelium - He

Others from Latin or foreign language names

Silver Ag Argenitum (Latin)

Tungsten W Wolfran (German)1st letter always capitalized, 2nd is lower case

Atoms and Elements

Compounds and Molecules

Atoms want to be stable, want a complete outer energy level

Combine with other elements; both become stable

Compound – substance formed when 2 or more elements bond chemically

Compounds and Molecules

Stability by sharing or transferring electronsCovalent Bond – electrons are shared

Molecule – bonded set of atoms Ionic Bond – electrons are transferred

Ion – electrically charged atomNegative Ion – gain electronsPositive Ion – loses electrons

Bond forms due to attraction of oppositely charged ions

Compounds and Molecules

Covalent Bonds – Water (H2O)

Compounds and Molecules

Ionic Bonds – Sodium Chloride (NaCl)

Compounds and Molecules

Chemical Formula – Expression of chemical makeup of a compound

Shows kinds and number of atomsH2O – 2 atoms hydrogen; 1 atom oxygen

Coefficients show number of molecules2H2O – 2molecules; 4 atoms H; 2 atoms O

Mixtures

Composed of 2 or more substances that can be separated by physical means

Homogeneous – every part looks sameHeterogeneous – some sections look different

TypesSolutionSuspensionColloid

Mixtures

SolutionHomogeneous mixture where one substance is dissolved in another

Solute – Substance dissolvedSolvent – Substance doing the dissolving

Mixtures

SuspensionHeterogeneous mixture of substances larger than molecules or ions

Particles may settle Some stay suspended; cloudy appearance

Example - Blood

Mixtures

ColloidHomogeneous mixture with particles larger than in solution but smaller than a suspension

Clusters of atoms, ions or molecules

Examples – Gelatin, Homogenized Milk

Life’s Chemicals

Most atoms in Human Body

HydrogenOxygenCarbonNitrogen

Life’s Chemicals

Inorganic CompoundsPrimarily composed of elements other than Carbon

Organic CompoundsContain the element Carbon

Water

Most abundant inorganic compound in living organisms

Composed of Hydrogen and Oxygen

Water

Universal Solvent – dissolves many substances due to polarity of waterDissolves ionic compounds to produce ions called electrolytesDoesn’t dissolve covalent compounds very well

Water

Water

Dissociates to form H+ and OH- ionsBoth are equal in distilled water

Gives us the pH scaleBelow 7 – acidicAbove 7 – alkaline7 - neutral

Water

Water

Polarity of water Causes hydrogen bonding – bond between H of one and O of another.

Results in water’s unique propertiesBoiling and Freezing PointsCohesion – attracted to other water molecules – water dropletsAdhesion – attracted to other similar molecules – allows movement of water in plants

Carbon Dioxide

Inorganic even though it contains carbon

Source of Carbon and Oxygen in organic compounds by way of photosynthesis

Organic Compounds

Contain the element CarbonHas 4 electrons in outer energy level

Can form 4 bonds – either with other carbons or other elements

Organic Compounds

Originally believed to have to come from living organisms

Many have been synthesized

Organic Compounds

Often described by structural formulasShow kinds of atomsShow number of atomsShow how atoms are attached to each other

Organic Compounds

Organic Compound important to Life

CarbohydratesProteinsLipidsNucleic Acids

Organic Compounds

Processes (reactions) important to organic compounds

Dehydration SynthesisProduction of a more complex molecule from 2 or more simpler molecules by removing a water molecule

HydrolysisBreakdown of a more complex molecule into simpler molecules by the addition of a molecule of water – usually during digestion

Organic Compounds

Carbohydrates

Composed of Carbon, Hydrogen, and OxygenHydrogen: Oxygen ratio always 2 to 1

Used for energy source, structure, and energy storage

ClassesMonosaccharidesDisaccharidesPolysaccharides

Carbohydrates

Monosaccharides – single sugars

Most have formula C6H12O6 –different structures

Examples – glucose, fructose, galactose

Glucose – food product of photosynthesis

Carbohydrates

Carbohydrates

Disaccharides – double sugars

Composed of 2 monosaccharides that combine by dehydration synthesis

Molecular formula – C12H22O11

ExamplesSucrose (Table Sugar) – Glucose + FructoseLactose (Milk Sugar) – Glucose + Galactose

Carbohydrates

Carbohydrates

Polysaccharides – many sugars

Made of many monosaccharides that combine during a series of dehydration syntheses

TypesCellulose – structural compound in plantsStarch – energy storage in plantsGlycogen – energy storage in animal

livers;called “animal starch”

Carbohydrates

Proteins

Composed of Carbon, Hydrogen, Oxygen, and Nitrogen; sometimes Sulfur

Made up of 20 different Amino Acid joined together by dehydration synthesis reactions.

Peptide Bonds join the amino acids – amino group of one amino acid attaches to carboxyl group of another amino acid

Proteins

Used to build and repair cells; also function as enzymes.

Types Dipeptide – 2 amino acids Polypeptide – many amino acids

Proteins

Amino Acid Structure

3 basic parts around a central CarbonAmino Group – NH2

Carboxyl Group – COOHR-Group – a simple H or group of

Carbon and Hydrogen atomsHydrogen forms the 4th bond.

Proteins

Proteins

Enzyme - protein molecule that acts as an organic catalyst – changes the rate of chemical reaction

Acts on a Substrate – Material to be changed

Often described as a “Lock and Key” operation

Lock – substrateKey - enzyme

Proteins

Lipids

Contain Carbon, Hydrogen, and OxygenLarger number of Hydrogen atoms and lower number of Oxygen atoms than carbohydrates

Insoluble in water

Most composed of Fatty Acids

Primary function is energy storage but help form cell membranes

Lipids

Fatty Acids

Large straight chain hydrocarbon with a carboxyl group at one end

Carboxyl Group – HydrophilicHydrocarbon Chain – Hydrophobic

Lipids

Saturated Fatty Acid

Unsaturated Fatty Acid

Lipids

Kinds

Triglycerides – 3 fatty acids bonded to a glycerol by dehydration synthesis

Oil – Liquid at room temperatureFat – Solid at room temperature

Wax – Long fatty acid bonded to long alcoholSteroids – Rings of 4 Carbons; hormones, nerve tissue, some plant and animal poisons

Lipids

Triglyceride

Lipids

Phospholipids

Nucleic Acids

Complex molecules that store and transmit important information about the cell

Involved with transmission of characteristic during cell reproduction

Types Deoxyribonucleic Acid – DNARibonucleic Acid – RNA

Nucleic Acids

DNA and RNA – composed of thousands of nucleotides

Nucleotides – composed of 3 parts formed by dehydration synthesis

Parts5-Carbon Sugar – Ribose or DeoxyribosePhosphate GroupNitrogen Base – Guanine, Cytosine, Adenine, Thymine, or Uracil

Nucleic Acids

Nucleic Acids

Nucleic Acids

Deoxyribonucleic Acid

Stores information essential for cell activitiesFound mostly in the cell nucleus

Ribonucleic Acid

Stores and transfers information to make proteins

Nucleic Acids