Unit III - Biochemistry

Hierarchy of OrganizationEcosystem Community Population Organism Organ System Organ Tissue Cell Organelle Molecule Atom

Why is water so important to life?What does it do that is so important?

Water allows for easier transport…

Water allows chemical reactions to occur…■ Most reactions require dissolved chemicals

Water holds heat very well…■ Aquatic organisms do not have wild temp change

■ Coastal habitats have less temp fluctuation■ Your body temp does not fluctuate wildly

Frozen water floats on liquid water…■ Aquatic life is insulated from cold

temperatures when the top layer is frozen

Why water? Why is it so special?

Electronegativity!(how hard atoms pull on electrons)

Remember this?

Atoms need 8 electrons on outer shell (or a full outer shell) to be “happy”

Atoms need 8 electrons on outer shell (or a full outer shell) to be “happy”

Atoms need 8 electrons on outer shell (or a full outer shell) to be “happy”

Atoms need 8 electrons on outer shell (or a full outer shell) to be “happy”

Who wants those electrons more – H or O?

Atoms need 8 electrons on outer shell (or a full outer shell) to be “happy”

This POLARITY

is the reason why water is so

special!

Do you remember these from yesterday?

WaterWhy is Water Important

to Organisms?❑ Bathes cells❑ Needed for chemical

reactions❑ Used for transport❑ Holds/transfers heat

WaterWhy is water so special? …it has POLARITY

occurs because O pulls electrons harder than H’s pull…makes each have a slight charge

WaterWater’s charged sides attract to other molecules

with charges (it’s kinda “sticky”)❑ These are called hydrogen bonds❑ Are weaker than ionic/covalent, but they add up!

hydro- water

Water■ Water has many special properties, most of

which occur because of the hydrogen bonding

■ As you go through each of the properties be sure to look for 3 things:❑ Definition of the property❑ Why the property happens❑ Why the property is important to organisms

WaterSpecial properties:ADHESION - attraction btwn water & another type

of molecule- where did you see that on your mini-lab?

COHESION - water sticks to itself- where did you see that on your mini-lab?

WHY does it happen? Polar (sticky ends) grab each other

co - together

WaterA special type of adhesion…

capillarity: water “climbs” up thin tubes

Ex: water moves thru tubes in plants and animals (veins, etc)

WaterA special type of cohesion…

surface tension: forms strong layer; beads up

WHY? hydrogen-bonds make water stick to itselfEx: bugs on water surfaces; dew droplets gather

on leaves

co - together

WaterSpecial properties:

high specific heat: - water holds its heat very well (hard to change its temp)

- must break a lot of H-bonds before energy can be used to raise temp

- Ex: coastal/aquatic ecosystems & individual organisms are protected from wild temp changes, Costal

towns are more humid in temps

WaterSpecial properties:

high heat of vaporization: - lots of heat is removed as water goes from liquid to gas

WHY? The hottest molecules leave first & fastest (lowers the average temperature)

- Ex: sweating

WaterSpecial properties: ice floats on water:

- solid H2O is less DENSE than liquid water

WHY? the H-bonds hold molecules far apart (more VOLUME)

- Ex: lakes freeze from top down… insulates aquatic life below

WaterSpecial properties:universal solvent: water dissolves many substances - water will dissolve things that have charges (ionic & polar covalent compounds) - Ex: most chemical reactions require aqueous solutions

(dissolved substances)

pH – a measure of H+ ions scale is 0 - 14

■ acids❑ pH < 7 ❑ tend to start with “H”; ex: HCl

■ bases❑ pH >7❑ tend to end in “OH”; ex: NaOH

pH – a measure of H+ ions Scale is 0 - 14❑ each pH level is 10 times more than next❑ pH 3 is 10x more acidic than pH 4❑ pH 3 is 100x more acidic than pH 5

■ Why pH matters to life –❑ Chemical rxns require specific pH levels❑ Acid rain affects ecosystems❑ Some enzymes are broken by extreme pH

■ Buffers - ❑ What? - Chemicals that keep pH stable❑ Why? - Reactions may not work if at wrong pH

pH – a measure of H+ ions

Bell Ringer

■Finish your reflections❑Pre-AP= 10-12 sentences on why water is

important to life, and list and describe the water properties

❑Biology= 6-8 sentences on why water is important to life, and list (briefly describe) the water properties

Organic Compounds■ Organic compounds come from organisms■ They include 4 major groups:

❑ carbohydrates, lipids, nucleic acids, & proteins■ All are very large molecules built from small units■ Monomer = building block■ Polymer = large molecule

mono - onepoly - many

Organic Compounds■ Monomers can be joined to each other to make

polymers ■ They are joined by removing water

❑ Called dehydration synthesis (or condensation) “to make by removing water”

hydr – watersyn - together

Organic Compounds■ Polymers can be broken apart into monomers

❑ This process breaks larger molecule by adding water❑ Called hydrolysis “to break with water”

hydr – waterlys - burst

Organic CompoundsCarbohydrates (C,H,O)

■ Structuremonosaccharide:

polysaccharide: (monomer) (polymer)

mono- onepoly- manysacchar- sugar

Organic Compounds

CarbohydratesExamples of Simple Sugars

❑ Glucose (simple sugar) - cell energy

❑ Others: fructose, dextrose, … (end in “ose”

Organic Compounds

CarbohydratesExamples of Polysaccharides

❑ Starch – how plants store extra glucose

❑ Glycogen – how animals store extra glucose

❑ Cellulose – makes up cell walls of plants; dietary fiber

❑ Chitin – makes up cell walls of fungi/insect exoskeletons

Organic CompoundsLipids (C,H,O)

Structure – nonpolar (do not like water) monomer is the fatty acid chain

Organic CompoundsLipids

Types: ■ saturated fats – hold as much H as possible;

solid at room temp; animal fats

Organic CompoundsLipids

■ Types:■ unsaturated fats – missing H due to multiple

bonds; liquid at room temp; plant oils

Organic CompoundsLipids

Examples – ❑ Triglycerides – fats & oils used for long-term energy storage

tri- threeglyc- sugar

Organic CompoundsLipids

Examples – phospholipids: have polar side & nonpolar side; make up cell membrane

steroids: ringed molecules; hormones (cholesterol, testosterone, estrogen)

Organic CompoundsNucleic Acids (C,H,O,N,P,S)

Monomer is the nucleotide:

Examples: DNA, RNA (genetic material- hereditary info)

Organic CompoundsProteins

(C,H,O,N,S)Monomer is the amino acid:

Organic CompoundsProteins

Examples: numerous! ❑ Collagen❑ Hemoglobin❑ Insulin❑ Enzymes (pepsin, etc)

Functions – build structures, enzymes, hormones

Organic CompoundsProteins

Structure – simple proteins: complex proteins:

On page 31- testing unknowns■Carbohydrate test❑BENEDICT’S TEST❑IODINE TEST

■Lipids test❑PAPER TOWEL TEST

Results from testingBenedicts and Iodine Lipids

Biuret test (proteins)

Bell Ringer Activity Page 30

■In your table group, you will be working on your COMPARING BIOMOLECULES sheet.

■This is for a grade, and you will see this on your quiz tomorrow as well as your test next week

Enzymes (Special Proteins!)■ Enzymes are needed in order to SPEED UP

reactions■ The enzyme does NOT get USED in the reaction

■ https://www.youtube.com/watch?v=CZD5xsOKres

Enzymes (Special Proteins!)■ Enzymes are very SPECIFIC – they only work with one reaction

■ Every chemical reaction has at least ONE enzyme■ If an enzyme is missing, a DEFECT will result

❑ Ex: ALBINOS are missing enzyme for melanin…lactose-intolerant people are missing LACTASE

Enzymes (Special Proteins!)■ NAMING ENZYMES❑ Usually end in “ase” (name usually linked to

substrate)❑ Note: enzymes do NOT always break down

things…they work for building reactions too!

SUBSTANCES A B PRODUCT AB

ENZYME ENZYME

Naming Enzymes

■Usually ends with ase

■ Lactase breaks down lactose■Sucrase breaks down sucrose■Peptidase/pepsin breaks down protein■Catalase breaks down water based

compounds (fat soluble, polarity etc)■Amylase breaks down starch

III.Enzymes (Special Proteins!)■ Enzymes must be in the correct SHAPE or their

substrates will not fit in with them■ Unfolding of an enzyme is called DENATURATION

❑ May be caused by BOILING (high heat), or strong acids/bases (extreme pH’s)

Self-Quiz – Chemistry■ 1. Water moving thru tiny tubes is -

A. capillarity C. cohesion B. surface tension D. specific heat■ 2. Which of the following is the weakest?

A. ionic bonds C. hydrogen bondsB. electrovalent bonds D. covalent bonds

Self-Quiz – Chemistry■ 3. Most of water’s special properties are due

to the fact that it is –A. polar B. neutral C. covalent D. nonpolar

■ 4. Weak attractions between water molecules are - A. covalent bonds C. Ionic bondsB. H-bonds D. nonpolar bonds

Self-Quiz – Chemistry■ 5. To build polymers,

A. monomers are hydrolyzed C. water is addedB. monomers are broken down D. water is removed

■ 6. Hydrolysis -A. builds muscle tissue C. is used in digestionB. creates water D. produces polymers

Self-Quiz – Chemistry■ 7. Crabs in a lake don’t worry about wild temperature

changes in their home because water has -A. less density as a solid C. high specific heatB. capillarity D. high surface tension

■ 8. Water forms droplets due to its -A. covalent bonding C. high heat of vaporizationB. cohesion D. hydrolization

Self-Quiz – Chemistry■ 9. What does “polarity” actually mean?■ 10. What is a “monomer”?■ 11. What is the monomer for carbohydrates called?■ 12. Name 2 food sources high in carbs.

The End

Lab – Enzyme Reactions■ I. Purpose: How does a strong acid and high

temperature affect enzyme activity?■ II. Background: Enzymes make chemical reactions

go faster.■ III. Hypothesis: Strong acid will make an enzyme

reaction go ___. High temp will make an enzyme reaction go ___.

■ IV. Procedure: (draw picture)

Lab – Enzyme Rate of ReactionI. Purpose: How does the level of ___ affect the rate of reaction involving the enzyme catalase & hydrogen peroxide?

II. Background: state what you know about the question (what you know about enzymes, substrate, the variable tested, etc)

III. Hypothesis: An increase in ___ will cause the rate of reaction to ___.

IV. Procedure: (sketch & label your design)

Lab – Enzyme Rate of ReactionIV. Procedure: (sketch & label your design)

V. Data: (create your data table and graph axes here)

VI. Conclusion: (must be complete sentences for credit!)

- data summary - support or not - SoE - how to fix

Lab - Denaturation■ V. Data Describe what happened.■ VI. Conclusion Strong acid causes enzyme reactions to… High temp causes enzyme reactions to… This effect is called ____________.

Solid water floats…solid oil sinks!