Biology IBiology I

Basic Chemistry & Basic Chemistry & Biochemistry:Biochemistry:

The Chemical Basis of LifeThe Chemical Basis of Life

Part I: Basic Chemistry:Part I: Basic Chemistry:Key Words and ConceptsKey Words and Concepts

• ElementElement• AtomAtom• CompoundsCompounds• MoleculeMolecule• IonsIons• Acid and BaseAcid and Base• pHpH• Diffusion and OsmosisDiffusion and Osmosis

Review: Basic ChemistryReview: Basic Chemistry• MatterMatter

• anything that has a mass and takes up a spaceanything that has a mass and takes up a space• all matter is composed of elementsall matter is composed of elements

• ElementElement• is a substance that can not be broken down is a substance that can not be broken down

into simpler substances. Example: oxygen (O), into simpler substances. Example: oxygen (O), hydrogen (H), carbon (C)hydrogen (H), carbon (C)

• Each element has a set of properties that Each element has a set of properties that distinguish it from from other elements. distinguish it from from other elements. Example: copper is a bronze colored solid that Example: copper is a bronze colored solid that conducts heat; oxygen is odorless/colorless at conducts heat; oxygen is odorless/colorless at room temperature.room temperature.

Review: Basic Review: Basic ChemistryChemistry

• AtomAtom• is the smallest particle of an element that is the smallest particle of an element that

retains the characteristics of that element retains the characteristics of that element • Example: all atoms of copper have the Example: all atoms of copper have the

properties of copperproperties of copper

• The center of each atom contains a The center of each atom contains a nucleusnucleus composed of 2 different particles: composed of 2 different particles: protonsprotons (+ charge) and (+ charge) and neutronsneutrons (with no (with no charge)charge)

• Moving in regions outside the nucleus is a Moving in regions outside the nucleus is a particle called the particle called the electronelectron (- charge) (- charge)

Structure of an AtomStructure of an Atom

Review: Basic Review: Basic ChemistryChemistry

• AtomAtom• Every atom in an element has an equal Every atom in an element has an equal

number of protons and electrons, and number of protons and electrons, and is electrically balanced, or neutralis electrically balanced, or neutral

• Every atom has energy, or the ability Every atom has energy, or the ability to do workto do work

• This energy (called chemical energy), This energy (called chemical energy), comes from electrons in the atomcomes from electrons in the atom

Review: Basic ChemistryReview: Basic Chemistry• CompoundsCompounds

• Substances made from elements are Substances made from elements are compounds. compounds. A chemical formula shows the A chemical formula shows the kinds and proportions of atoms in a compound. kinds and proportions of atoms in a compound. Ex: NaCl stands for sodium chloride (salt) from Ex: NaCl stands for sodium chloride (salt) from sodium (Na) and chlorine (Cl)sodium (Na) and chlorine (Cl)

• MoleculesMolecules• Are the smallest units of a compound that still Are the smallest units of a compound that still

have the properties of that compound. (in Hhave the properties of that compound. (in H22O, O, the ratio of H and O is 2:1, so the formula is the ratio of H and O is 2:1, so the formula is HH22O)O)

• IonsIons• Electrically charged (+/-) molecules are called Electrically charged (+/-) molecules are called

IONSIONS

Review: Basic ChemistryReview: Basic Chemistry• Acids and BasesAcids and Bases

• Two common groups of compounds Two common groups of compounds that react in water are ACIDS and that react in water are ACIDS and BASESBASES

• Acid is a substance that releases Acid is a substance that releases hydrogen ions (protons) when mixed hydrogen ions (protons) when mixed with water (proton donor) with water (proton donor)

• Example: CHExample: CH33COOH --–HCOOH --–H220– H0– H++ + CH + CH33COOCOO––

• Base is a substance that separates in Base is a substance that separates in water, forming ions that react with water, forming ions that react with hydrogen ions (proton acceptor) hydrogen ions (proton acceptor)

• Example: NaOH + CHExample: NaOH + CH33COOH --– HCOOH --– H220 + CH0 + CH33COONaCOONa

Review: Basic Review: Basic ChemistryChemistry

• pHpH• The strength of an acid or base is measured The strength of an acid or base is measured

by the pH scale (0-14, 7 being neutral: water)by the pH scale (0-14, 7 being neutral: water)

• pH of acid solution: 0-7; of basic solution 7-14pH of acid solution: 0-7; of basic solution 7-14

• The pH scale is based on powers of 10. Thus The pH scale is based on powers of 10. Thus Cola with a pH of 3 is 10 times more acidic Cola with a pH of 3 is 10 times more acidic than Tomato juice with a pH of 4than Tomato juice with a pH of 4

• Living cells are very sensitive to pH of their Living cells are very sensitive to pH of their environment. Our cells are in a pH of 7.2. If environment. Our cells are in a pH of 7.2. If the pH changes by only 2/10the pH changes by only 2/10thth of a point, cells of a point, cells diedie

Review: Basic ChemistryReview: Basic Chemistry• Diffusion & OsmosisDiffusion & Osmosis

• DiffusionDiffusion : movement : movement of a of a molecule/substance molecule/substance from a higher to a from a higher to a lower concentrationlower concentration

• OsmosisOsmosis : movement : movement of water molecules of water molecules through a semi-through a semi-permeable membrane permeable membrane from a higher to a from a higher to a lower water lower water concentrationconcentration

BiochemistryBiochemistry

What is What is Biochemistry?Biochemistry?

• Biochemistry is the study of the Biochemistry is the study of the chemical interactions of living chemical interactions of living things.things.

• Biochemists study the structures Biochemists study the structures and physical properties of biological and physical properties of biological molecules.molecules.• Often are involved in the manufacture Often are involved in the manufacture

of new drugs and medical treatmentsof new drugs and medical treatments

Elements in Living Elements in Living OrganismsOrganisms

• The most common elements found The most common elements found in living organisms include:in living organisms include:

•Carbon (C)Carbon (C)•Oxygen (O)Oxygen (O)•Nitrogen (N)Nitrogen (N)•Hydrogen (H)Hydrogen (H)•Phosphorus (P)Phosphorus (P)•Sulfur (S)Sulfur (S)

Periodic Table of the Elements Periodic Table of the Elements (excerpt)(excerpt)

Biochemistry: Biochemistry: Where Chemistry & Biology Where Chemistry & Biology

MeetMeet• Living things require millions of Living things require millions of

chemical reactions just to survive.chemical reactions just to survive.• Metabolism = all the chemical Metabolism = all the chemical

reactions occurring in the body. reactions occurring in the body. • Organic molecules: Organic molecules:

• usually associated with living things. usually associated with living things. • always contain CARBON.always contain CARBON.• are “large” molecules, with many atomsare “large” molecules, with many atoms• always have covalent bonds (share electrons)always have covalent bonds (share electrons)

Macromolecules of Macromolecules of CellsCells

• Macro = largeMacro = large• 4 types of macromolecules4 types of macromolecules

1. Carbohydrates1. Carbohydrates

2. Lipids2. Lipids

3. Proteins3. Proteins

4. Nucleic Acids4. Nucleic Acids

Macromolecule #1: Macromolecule #1: CarbohydratesCarbohydrates

• Sugars and groups of sugarsSugars and groups of sugars• Purposes: energy and structurePurposes: energy and structure• Includes three types:Includes three types:

• Monosaccharide (1 sugar – quick Monosaccharide (1 sugar – quick energy)energy)

• Disaccharide (2 sugars – short storage)Disaccharide (2 sugars – short storage)• Polysaccharide (many sugars – energy Polysaccharide (many sugars – energy

long storage & form long storage & form structures)structures)

Macromolecule #1: Macromolecule #1: CarbohydratesCarbohydrates

• Polysaccharide Examples: Polysaccharide Examples: •Glycogen— Glycogen— stored for future stored for future

energy needs. Found in liver, energy needs. Found in liver, muscle & sperm.muscle & sperm.

•Cellulose— Cellulose— used to form fibers used to form fibers for plant structures. Humans can’t for plant structures. Humans can’t digest (fiber). Most abundant digest (fiber). Most abundant organic molecule.organic molecule.

•Chitin— Chitin— exoskeletons of some exoskeletons of some crustaceans & insects.crustaceans & insects.

PolysaccharidesPolysaccharides

PolysaccharidesPolysaccharides

Macromolecule #2: Macromolecule #2: LipidsLipids

• Insoluble in water (think oil & water)Insoluble in water (think oil & water)

4 types: 4 types: • 1-triglycerides (fats & oils)1-triglycerides (fats & oils)

• (long-term energy storage, insulation)(long-term energy storage, insulation)

• 2-phospholipids (cell membranes)2-phospholipids (cell membranes)• 3-steroids (cell signaling)3-steroids (cell signaling)

• cholesterol molecules modified to form sex cholesterol molecules modified to form sex hormones. (e.g. testosterone, estrogen, etc.)hormones. (e.g. testosterone, estrogen, etc.)

• 4-waxes (protection, prevents water loss)4-waxes (protection, prevents water loss)• Used mainly by plants, but also bees, some Used mainly by plants, but also bees, some

furry animals and humans. furry animals and humans.

Triglycerides

Phospholipids

SteroidsSteroids

WaxesWaxes

Macromolecule #3: Macromolecule #3: ProteinsProteins

• Most complicated of all biological molecules. Most complicated of all biological molecules. • Serve the most varied purposes, including:Serve the most varied purposes, including:

SupportSupport structural proteins (e.g., keratin, collagen)structural proteins (e.g., keratin, collagen)

EnzymesEnzymes speed up chemical reactionsspeed up chemical reactions

TransportTransport cell membranes channels, transporters in blood cell membranes channels, transporters in blood

(e.g., Hemoglobin)(e.g., Hemoglobin)

DefenseDefense antibodies of the immune systemantibodies of the immune system

HormonesHormones cell signaling (e.g., insulin)cell signaling (e.g., insulin)

MotionMotion contractile proteins (e.g., actin, myosin)contractile proteins (e.g., actin, myosin)

CollageCollagenn

AntibodiAntibodieses

Cellular Transport

actin & myosin fibers

in muscles

Motion

Macromolecule #3: Macromolecule #3: ProteinsProteins

• The building blocks of proteins are The building blocks of proteins are AMINO ACIDS. There are only 20 AMINO ACIDS. There are only 20 types of Amino Acids.types of Amino Acids.

• There are millions of different There are millions of different proteins, and they are all built from proteins, and they are all built from different combinations of the 20 different combinations of the 20 amino acids. amino acids.

• Amino acids join together to form Amino acids join together to form peptides, polypeptides, and peptides, polypeptides, and polypeptide chains.polypeptide chains.

Macromolecule #4: Nucleic Macromolecule #4: Nucleic AcidsAcids

• Nucleotides: building blocks of nucleic acids.Nucleotides: building blocks of nucleic acids.• Each nucleotide contains Each nucleotide contains

• (a) phosphate molecule, (a) phosphate molecule, • (b) nitrogenous base, and (b) nitrogenous base, and • (c) 5-carbon sugar(c) 5-carbon sugar

• Several types of nucleic acids, including:Several types of nucleic acids, including:• DNA: deoxyribonucleic acidDNA: deoxyribonucleic acid

• Genetic material, double stranded helixGenetic material, double stranded helix• RNA: ribonucleic acidRNA: ribonucleic acid

• Genetic material, single strandedGenetic material, single stranded• ATP: adenosine triphosphateATP: adenosine triphosphate

• High energy compoundHigh energy compound

DNADNA

Nucleotide Structure

CHEMISTRY IS LIFE…CHEMISTRY IS LIFE…