Intro to Biology & Intro to Biology & BiochemistryBiochemistry

Ch. 1 & 2Ch. 1 & 2

BiologyBiology - study of living things - study of living things

OrganismOrganism– complete, individual living – complete, individual living thingthing

Characteristics of Living Things Characteristics of Living Things

1. All organisms are made of 1. All organisms are made of cells cells - these are - these are the basic building blocks (smallest unit that the basic building blocks (smallest unit that can carry on the activities of life)can carry on the activities of life)unicellularunicellular – organism composed of a single – organism composed of a single cell (bacteria)   cell (bacteria)   

          multicellularmulticellular– more than 1 cell (humans)– more than 1 cell (humans)

2. Organisms are 2. Organisms are highly organized – the highly organized – the basic difference basic difference between organisms is between organisms is the way they the way they synthesize raw synthesize raw materialsmaterials– cells are – cells are like miniature like miniature factories.  Living factories.  Living things are based on a things are based on a universal genetic universal genetic codecode. .

3. Organisms use 3. Organisms use energy energy – the ultimate – the ultimate source of energy is source of energy is sunlightsunlight – Plants – Plants typically store excess energy as typically store excess energy as oils oils while while animals typically store excess energy as animals typically store excess energy as fatsfats

MetabolismMetabolism– sum of chemical building up – sum of chemical building up (anabolism)(anabolism) & breaking down & breaking down (catabolism)(catabolism)

4. Organisms grow & develop – growth is 4. Organisms grow & develop – growth is increasing in size increasing in size while development is while development is maturation.maturation.

5. Organisms have a 5. Organisms have a life spanlife span (average (average length of life) & all organisms maintain a length of life) & all organisms maintain a stable internal environment – this is called stable internal environment – this is called homeostasishomeostasis.  . 

6. Organisms 6. Organisms reproducereproduce– this is – this is necessary for the continued existence of necessary for the continued existence of the the speciesspecies.  In .  In sexual reproductionsexual reproduction, 2 , 2 cells from different parents unite to cells from different parents unite to produce the first cell of the new organism produce the first cell of the new organism (offspring & parents have different traits).  (offspring & parents have different traits).  In In asexual reproductionasexual reproduction, the new , the new organism has a single parent (offspring & organism has a single parent (offspring & parents have the same traits).parents have the same traits).

7. Organisms respond to a 7. Organisms respond to a stimulus stimulus - this - this is any condition to which an organism can is any condition to which an organism can react; the resulting action is called a react; the resulting action is called a responseresponse; ; irritability irritability refers to the ability refers to the ability to respond to stimuli to respond to stimuli

8. Organisms adjust to their 8. Organisms adjust to their environmentenvironment– one must adapt to survive – one must adapt to survive – any change in an organism that makes it – any change in an organism that makes it better suited to its environment is an better suited to its environment is an adaptive responseadaptive response.  .  Variation Variation refers to a refers to a set of differences among individuals – set of differences among individuals – sometimes these variations may give the sometimes these variations may give the organism an edge over others.  Any kind organism an edge over others.  Any kind of organism can change, or of organism can change, or evolve evolve over over time.time.

The Scientific Method – a logical, The Scientific Method – a logical, organized method of study organized method of study

1. 1. State the problemState the problem

2. 2. Collect Collect information information (use all (use all available sources – available sources – library, internet, library, internet, magazines, magazines, interviews) interviews)

3. Formulate a 3. Formulate a hypothesishypothesis – a – a statement that can statement that can be tested.  It should be tested.  It should be short, definitive, & be short, definitive, & positive. positive.

4. 4. ExperimentExperiment.  This .  This involves testing the involves testing the hypothesis.  A hypothesis.  A variable variable is is a condition that changes a condition that changes in the experiment.  in the experiment. 

Independent variables Independent variables may be controlled by the may be controlled by the experimenter.  These experimenter.  These belong on the x-axis of a belong on the x-axis of a graph.  graph. 

Dependent variables Dependent variables are typically the are typically the results.  These belong on the y-axis of a results.  These belong on the y-axis of a graph.  A graph.  A controlled experimentcontrolled experiment is one in is one in which there is only 1 experimental variable which there is only 1 experimental variable (all of the conditions are alike except for (all of the conditions are alike except for the one being tested).  The the one being tested).  The experimental experimental groupgroup is exposed to the experimental is exposed to the experimental variable while the variable while the control group control group is not.  In is not.  In scientific experiments, only one variable is scientific experiments, only one variable is changed at a time.  changed at a time. 

5. Make & record 5. Make & record observationsobservations.  This .  This includes data, statistics, graphs, etc. includes data, statistics, graphs, etc. QuantitativeQuantitative observations involve observations involve numbers – counting or measuring objects.  numbers – counting or measuring objects.  Qualitative Qualitative observations involve observations involve characteristics that can’t be counted – ex. characteristics that can’t be counted – ex. = color, texture, etc.= color, texture, etc.

6. Draw a 6. Draw a conclusionconclusion.  This may or .  This may or may not support the original may not support the original hypothesis.hypothesis.

Redi’s Experiment with Redi’s Experiment with Spontaneous GenerationSpontaneous Generation

Spallanzani’s ExperimentSpallanzani’s Experiment

Pasteur’s ExperimentPasteur’s Experiment

A scientific A scientific lawlaw explains how an event explains how an event occurs while a scientific occurs while a scientific theorytheory explains explains why an event occurs.  It is a well-tested why an event occurs.  It is a well-tested explanation that unifies a broad range of explanation that unifies a broad range of observations.  observations.  An An inferenceinference is a logical interpretation is a logical interpretation based on prior knowledge & experience.based on prior knowledge & experience.   

ExamplesExamples

InferencesInferences

The dog’s tail is The dog’s tail is wagging because he is wagging because he is excited.excited.

The man is riding a The man is riding a bicycle because his car bicycle because his car won’t start.won’t start.

The Braves are leading The Braves are leading the wild card because the wild card because they are playing well they are playing well right now.right now.

ObservationsObservations

The dog’s tail is The dog’s tail is waggingwagging

The man is riding a The man is riding a bicyclebicycle

The Braves are leading The Braves are leading the wild cardthe wild card

Observation vs. InferenceObservation vs. Inference

Statement Observation Inference

Object A is round and orange.

Object A is a basketball.

Object C is round and black and white.

Object C is larger than Object B.

Object B is smooth.

Object B is a table-tennis ball.

Each object is used in a different sport.

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Observation vs. InferenceObservation vs. Inference

Microscopes Microscopes are used to study cells.  are used to study cells.  Magnification Magnification refers to the ability to make refers to the ability to make an image larger.  an image larger.  Resolution Resolution refers to the refers to the ability to show details clearly.  As ability to show details clearly.  As magnification increases, resolution magnification increases, resolution typically decreases.typically decreases.

Types of Microscopes Types of Microscopes 1.  1.  Compound lightCompound light- uses light - uses light

passing through 1 or more passing through 1 or more lenses to produce an image – lenses to produce an image – produce magnified images by produce magnified images by focusing visible light rays -  (we focusing visible light rays -  (we use these at school) – use these at school) – Magnification = Magnification = multiplying multiplying the the magnifications of the lensesmagnifications of the lenses

2.  2.  Electron microscopesElectron microscopes - these produce - these produce magnified images by focusing beams of magnified images by focusing beams of electronselectrons

a.  a.  Transmission e- microscopesTransmission e- microscopes – produces a – produces a stream of electrons that passes through a stream of electrons that passes through a specimen – thinly sliced, then stained – used to specimen – thinly sliced, then stained – used to view internal structure – magnifies up to view internal structure – magnifies up to 200,000x200,000x

b.  b.  Scanning e- Scanning e- microscopesmicroscopes – – beam of electrons beam of electrons reveals surface reveals surface details of images – details of images – gives 3-D gives 3-D appearance –appearance –specimens are specimens are coated with metal -  coated with metal -  magnifies up to magnifies up to 100,000x100,000x

BIOCHEMISTRY BIOCHEMISTRY

AtomsAtoms - are the building blocks of matter - are the building blocks of matter – They are made of – They are made of protonsprotons (positive (positive charge), charge), electronselectrons (negative charge), & (negative charge), & neutronsneutrons (no charge). Because the (no charge). Because the number of protons equals the number of number of protons equals the number of electrons, atoms have a electrons, atoms have a neutral neutral charge.  charge.  The The protons & neutrons protons & neutrons make up the make up the nucleus of an atom.  nucleus of an atom. 

ElementsElements - are pure substances that are - are pure substances that are made of only 1 type of atom.  made of only 1 type of atom.  MoleculesMolecules - are the smallest particles that - are the smallest particles that can have a stable, independent existence can have a stable, independent existence – they are typically joined by covalent – they are typically joined by covalent bonds.bonds.CompoundsCompounds - are groups of atoms held - are groups of atoms held together in definite proportions by together in definite proportions by chemical bondschemical bondsIsotopesIsotopes - are atoms of the same element - are atoms of the same element that differ in the number of neutrons they that differ in the number of neutrons they contain – they still have the same number contain – they still have the same number of protons. of protons.

IsotopesIsotopes

Chemical Bonds Chemical Bonds

All atoms strive for a All atoms strive for a stable octetstable octet 1) 1) Covalent bondsCovalent bonds- when atoms share - when atoms share

electrons – these are very strong; electrons – these are very strong; Example = Example = O2, H2OO2, H2O2)  2)  IonicIonic - molecules have opposite - molecules have opposite charges & transfer electrons – these charges & transfer electrons – these dissociate in water ; Example = dissociate in water ; Example = NaClNaCl

Ionic BondingIonic Bonding

INTERMOLECULAR FORCES: INTERMOLECULAR FORCES: 3)  3)  Hydrogen bondsHydrogen bonds- weak - weak

bonds – can’t form with long bonds – can’t form with long distances – these link distances – these link molecules rather than atoms; molecules rather than atoms; Example = Example = between the bases between the bases of DNAof DNA4)4)Van der Waals forcesVan der Waals forces - - slight attraction that develops slight attraction that develops between the oppositely charged between the oppositely charged regions of nearby molecules  - regions of nearby molecules  - holds molecules togetherholds molecules together

OrganicOrganic compounds are made by living things & compounds are made by living things & contain the element contain the element carboncarbon..InorganicInorganic compounds are not made by living things. compounds are not made by living things.

The elements that are crucial for life are C The elements that are crucial for life are C HOPKINS Ca Fe.HOPKINS Ca Fe.The elements that are considered macromolecules The elements that are considered macromolecules are are CHOPSNCHOPSN. .

WaterWater is the most important is the most important inorganic compound for living inorganic compound for living things.  Most cellular activities take things.  Most cellular activities take place in its presence.  Water is a place in its presence.  Water is a neutralneutral molecule (positive charges molecule (positive charges balance the negative charges).  balance the negative charges).  Water is a Water is a polar polar molecule because molecule because there is an uneven distribution of there is an uneven distribution of electrons between the oxygen & electrons between the oxygen & hydrogen atoms.  Drawing:hydrogen atoms.  Drawing:

Characteristics of water: Characteristics of water:

1.  1.  High heat capacityHigh heat capacity (this means it can (this means it can absorb & release great amounts of heat before absorb & release great amounts of heat before changing its temperature)changing its temperature)2.  2.  CohesionCohesion (this means it clings to itself – this (this means it clings to itself – this creates surface tension)creates surface tension)

3.  3.  AdhesionAdhesion (this means it clings to other (this means it clings to other molecules – this creates capillary action)molecules – this creates capillary action)

4.  4.  Water ionizes Water ionizes (when the covalent (when the covalent bonds break, a bonds break, a hydrogen ion and a hydrogen ion and a hydroxide ion are hydroxide ion are produced)produced)5.  5.  Universal solvent Universal solvent (this is because it is a (this is because it is a polar molecule)polar molecule)

A A mixture mixture is a material composed of 2 or more is a material composed of 2 or more elements or compounds that are physically elements or compounds that are physically mixed together but not chemically combined.  mixed together but not chemically combined.  The 2 parts of a solution are the The 2 parts of a solution are the solute solute (the (the substance being dissolved) & the substance being dissolved) & the solvent solvent (the (the substance in which it is dissolved). substance in which it is dissolved).

ACIDS & BASES ACIDS & BASES

Acid Acid - any compound that forms - any compound that forms hydrogen ions when dissolved in water – hydrogen ions when dissolved in water – proton proton donors, donors, electron electron acceptors, acceptors, increase {H+}, turns litmus paper increase {H+}, turns litmus paper redred, , found found below 7below 7 on the pH scale; Example on the pH scale; Example = = sulfuric acidsulfuric acid

Base Base - any compound - any compound that forms hydroxide that forms hydroxide ions when dissolved ions when dissolved in water – turns litmus in water – turns litmus paper paper blueblue, found , found above 7above 7 on the pH on the pH scale; Example = scale; Example = bleachbleach

The pH scale’s range The pH scale’s range is from is from 0 - 140 - 14.  .  Neutral is Neutral is 77.  The pH .  The pH scale is a scale is a logarithmic logarithmic scale meaning scale meaning it it increases or increases or decreases in powers decreases in powers of 10.of 10.

ORGANIC COMPOUNDS ORGANIC COMPOUNDS CarbonCarbon is the backbone of all organic is the backbone of all organic

molecules.  It can bond with other Carbons molecules.  It can bond with other Carbons to form rings or chains.  Carbon prefers to to form rings or chains.  Carbon prefers to have have 4 4 bonds.bonds.MonomersMonomers are basic units that repeat are basic units that repeat themselves.  When 2 or more of these themselves.  When 2 or more of these combine, a new compound is formed combine, a new compound is formed called a called a polymerpolymer. .

A A condensation condensation reaction is the process reaction is the process of joining monomers of joining monomers to build to build polymerspolymers.  In .  In the process, 2 the process, 2 hydrogens, and 1 hydrogens, and 1 oxygen are released & oxygen are released & these form these form water.water.

A A hydrolysis hydrolysis reaction reaction is the process of is the process of breaking down breaking down polymers into polymers into monomers.monomers.    Water Water is is necessary for this necessary for this reaction to occur.reaction to occur.

There are 4 Classes of Organic There are 4 Classes of Organic Compounds. Compounds.

1)Carbohydrates1)Carbohydrates 2)Lipids2)Lipids 3)Proteins3)Proteins 4) Nucleic Acids4) Nucleic Acids

CARBOHYDRATES CARBOHYDRATES Living things use carbs as their main Living things use carbs as their main

source of energysource of energy-contain the elements -contain the elements C, H, & O C, H, & O in a in a ratio of 1:2:1, meaning that if there are 6 ratio of 1:2:1, meaning that if there are 6 Carbon atoms, there will be Carbon atoms, there will be 12 12 hydrogen atoms & hydrogen atoms & 6 6 oxygen atomsoxygen atoms- examples of carbohydrates are - examples of carbohydrates are starches, sugars, & glycogenstarches, sugars, & glycogen- they are mainly used as structural or - they are mainly used as structural or energy storage moleculesenergy storage molecules

MonosaccharidesMonosaccharides - are sugars that can’t - are sugars that can’t be hydrolyzed into smaller units - be hydrolyzed into smaller units - examples are examples are glucose, galactose, glucose, galactose, fructose fructose - Their formula is - Their formula is CC66HH1212OO66..

They are all They are all isomers isomers of each other (they of each other (they have the same chemical formula but have the same chemical formula but different structural formulas)different structural formulas)

Disaccharides Disaccharides - result - result from the condensation from the condensation of 2 of 2 monosaccharidesmonosaccharidesExamples are Examples are

sucrosesucrose = glucose + = glucose + fructosefructose                                    

lactoselactose  = glucose +   = glucose + galactosegalactose

maltosemaltose = glucose + = glucose + glucoseglucose

Polysaccharides Polysaccharides - - 1000’s of sugars 1000’s of sugars combined; examples combined; examples are starch, glycgen & are starch, glycgen & cellulosecellulose

Sugar Sweetness

fructose 173%

sucrose 100%

glucose 74%

maltose 33%

galactose 33%

lactose 16%

LIPIDS LIPIDS - examples are - examples are fats, oils, fats, oils,

& waxes & waxes - they contain - they contain the elements the elements C, H, & OC, H, & O and consist of the and consist of the monomers monomers glycerolglycerol + 3 + 3 fatty acidsfatty acids- all are insoluble in water - all are insoluble in water because they are because they are nonpolarnonpolar compounds compounds- they are used for the - they are used for the storage of energy & in storage of energy & in hormone/steroid hormone/steroid synthesissynthesis

SaturatedSaturated fats contain all single bonds & fats contain all single bonds & are difficult for the body to break down.are difficult for the body to break down.UnsaturatedUnsaturated fats contain more double fats contain more double bonds & are easier for the body to attack.  bonds & are easier for the body to attack.  These are healthier for the body.  These These are healthier for the body.  These fats can be made saturated by fats can be made saturated by hydrogenationhydrogenation such as in Crisco (trans such as in Crisco (trans fats).  fats).  LipasesLipases are enzymes that break down fats are enzymes that break down fats & oils.& oils.

Lipids are essential for the body for Lipids are essential for the body for cell cell membranes, cushioning, hormone membranes, cushioning, hormone synthesissynthesis. .

PROTEINS PROTEINS - the basic building blocks - the basic building blocks

for the bodyfor the body- they contain the - they contain the elements elements C, H, O, N, & C, H, O, N, & sometimes Ssometimes S- they are - they are made of monomers known made of monomers known as as amino acidsamino acids- - polypeptides polypeptides are long are long chains of amino acidschains of amino acids- proteins are held - proteins are held together by together by peptide peptide bondsbonds

The 2 classes of proteins are 1) The 2 classes of proteins are 1) Structural Structural - these make hair, - these make hair, nails, ligaments, & tendons; & nails, ligaments, & tendons; &

2) 2) Dynamic Dynamic - these make things - these make things happens & include enzymes & happens & include enzymes & hemoglobinhemoglobin

Proteins have a native Proteins have a native configuration – this is their configuration – this is their original shape.  Most proteins original shape.  Most proteins that are denatured cannot be that are denatured cannot be annealed.annealed.

EnzymesEnzymes are proteins that act as are proteins that act as catalysts(speed reactions).  They lower catalysts(speed reactions).  They lower the activation energy but are not used up the activation energy but are not used up in the reaction.  They are specific (think in the reaction.  They are specific (think key & lock).  The key & lock).  The substratesubstrate is what the is what the enzyme acts on.  The enzyme acts on.  The active site active site is where is where the enzyme & substrate come into the enzyme & substrate come into contact. contact. CoenzymesCoenzymes help enzymes bind help enzymes bind to the substrate (vitamins).  to the substrate (vitamins).  InhibitorsInhibitors slow or stop enzyme activity by either slow or stop enzyme activity by either blocking the active site or distorting the blocking the active site or distorting the enzyme’s shape. enzyme’s shape.

NUCLEIC ACIDS NUCLEIC ACIDS

- these carry instructions for cellular activities – - these carry instructions for cellular activities – they store hereditary info to make proteinthey store hereditary info to make protein- nucleic acids are made from the monomers of - nucleic acids are made from the monomers of nucleotidesnucleotides- these are made of 1) a - these are made of 1) a nitrogennitrogen base (adenine, thymine, guanine, uracil, & base (adenine, thymine, guanine, uracil, & cytosine), 2) a cytosine), 2) a 5-C5-C sugar, & 3) a sugar, & 3) a phosphate phosphate group.group.

The 2 nucleic acids The 2 nucleic acids are are DNA & RNA. DNA & RNA. DNADNA is found in the is found in the nucleus & records nucleus & records instructions.  instructions.  RNA RNA is is found in the nucleus found in the nucleus & cytoplasm & reads & cytoplasm & reads instructions & carries instructions & carries them out.them out.