basic biochemistry 2010,part 1

8/8/2019 Basic Biochemistry 2010,Part 1

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Biochemistry Notes2010-2011


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How many elements and

compounds do you know??

See the provided sheet and lets fill it in

together- write down any you do not

already know!


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Parts of the atom

Nucleus has:

Protons=positive charge

Neutrons=no charge

Shells have:

Electrons=negative

charge


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Electron Orbitals

Region where there is 90%probability of finding an electron.

Cant pinpointthe location ofan electron.

Density of dotsrepresentsdegree ofprobability.


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Atomic number

Equals the # of protons in an atom-

all protons are located in the atom nucleus

Proton # is also the # of electrons-

As long as they remain equal, the atom isneutral in charge


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ATOMIC MASS Sum of the protons and neutrons in the

nucleus of an atom.

To find neutrons: Mass # - proton # =

# of neutrons

Lets see how this works..


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Element properties

determined by proton #


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Making Bohr Model Each shell has a maximum # of e- it can hold:

1st = 2

2nd = 8 3rd = 18

BUT when filling the 3rd, goes to 8 and then the nexte- is in the 4th shell!

SO for Bio- we willmemorize:

2-8-8-extra


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Lets Practice! Use the periodic table in your text or

planner. Make Bohr models of the

following:

N O Mg Ca

K Na Cl H F


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Isotopes Isotopes are elements that have the

same Proton # but different # of

neutrons-are radioactive


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Radioactive isotopes

When a nucleus breaks apart, it

giv

es off radiation that can bedetected and used for many


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C 12: C 14 ratio

P

Radioactivity and rate of

decay of C 14 to C 12 used to

determine age of young

fossils


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Ionic Bonding Ionic Bonds: One atom gives up electrons and

another takes it. This make them become ions.

Ions:o Charged atoms

Give up e- ---> become positive (+) Take e- ---> become negative ( - )

AFTER they become charged, then they BONDcalled IONIC bonding because

o Attraction between + and - ionso Ex: Li f orHCl or NaCl


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How ionic bond made: Li

F


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Did you hear about..? Two atoms are walking down the street.

One says, Wait, I think I lost an electron.

The other says, Are you sure?

The first one says, Yeah, Im positive.


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Covalent Bonding

Compound in which the atoms areheld

together by covalent bonds.Atoms share e-Ex: CO2, H2O

Methane (CH4)


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Comparing Covalent and Ionic

Bonding


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Lets Practice! Get into groups of 2

Using the package of supplies provided and

the paper template, follow directions to makebonds between the given molecules. Whenyou believe you have it right, call me over!

BE PREPARED to explain what and why you

set it up the way you did.


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Inorganic Molecules Contain C or H, usually not both

1. Acids - have H+ in solution

HCl H+ and Cl-

2 Bases - have O

H-

in solutionNaOH Na+ and OH-

QuickTi

e andadeco

ressorareneededtoseethis icture.

QuickTi e and adeco

ressorare needed to see this icture.


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Acids/Bases

3. Acid + base ---> salt + H2O

(neutralizes)

Ex: HCl + NaOH ---> NaCl + H2O

HCl + KO

H----> KCl +

H2O


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pH

= partsH

ydrogenpH scale

uickTime and adecompressor

are needed to see this picture.

Acid

rain

Stomach

AcidLemon

juice

Vinegar

Distilled

Water

Blood

Baking

soda AmmoniaNormal

rain

bleach

or basic

00Strongacid

Battery

acid

Strong

base


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pH

effects Ecosystems Availability of nutrients to plants effected by pH

Soil pH can effect flower and fruit production

A

cid rain- disrupt ecological processes/nutrient cycles Plants can change pH by decomposition or uptake ofnutrients/water and animal waste can change soil

ex:pine needles are very acidic

APPLICATION: gardeners apply lime to buffer acidic

soil


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6. p

HBuffers in organisms

Acid pH can effect shapes of molecules and how theywork in your body

Maintain normal pH conditions like in the bloodstream -

blood should be 7.4 one of the homeostatic mechanisms of the body.

Most of the human body is pH around 7. Stomach pH ~2

Ex: alkaseltzer for acid indigestion Buffers in bloodstream: balance pH

Bufferin - in aspirin, which is salycilic acid - helpsneutralize & doesnt add more acid to stomach


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7. Ulcers & heartburna. ulcers: blisters on stomach lining

* Most not caused by stress

* Most common cause: bacteria in stomach

lining, producing acid.


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Ulcers cont1. Normally lining replaced as acids eat it

away.

2. Lining eaten away if bacteria there - cantkeep up replacement

Blister from burn: ulcer

3. If perforated: acidic contents dumped onbody organs - not protected from burning- life threatening

4. Crackers/bread help with acid indigestionand acid reflux because they are basic -help buffer pH


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Heartburn cont

b. Has nothing to do withthe heart

Cause: stomach contentsgo back through cardiacsphincter

- esophagus burn is moreaccurate term

- Pregnant women:stomach squished: more

reflux


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The Structure of WaterTwo hydrogen atoms are each joined to an oxygen

atom by a single covalent bondvan der Waals

forces:The weak

attraction between

the hydrogen atom

of one moleculeand a slightly

negative atom

within another

molecule


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Properties of Water- A. Stable: covalent bonds btw O and H

not easily broken

Why is that important to life?


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Answer:

- Our bodies are mostly H2O

- We remain stable


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B. Good medium- Cant compress it, flows easily,

dissolves a lot of substances

What is that important to life?


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Answer

- Allows dissolving across membranes,

blood flows, etc.

- Diffusion depends on it


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c.H

igh specific heat- Absorbs/loses a lot of heat before changing

temperature

- 1. H2O temperature stable - like in ponds as well as

bodies- Warmer in ocean in Aug than June--took all winter to cool

- 2. Evaporative coolant - can dump heat from bodyreactions into H2O of bloodstream to radiate assweat.

What is that important to life?


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Answer

- Maintains body temp:

- Homeostasis


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D. DensityvT

emp1. Densest at 4C

Lightest at 0C

What is that

important to life?


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Answer:

Ice floats, liquid cold

H2O sinks =

organisms can livethrough winter under

ice/ whole pond

doesnt freezeH2O continues to flow

in rivers


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E. Solubility of O2v

s.T

1. Cold H2O holds more O2than warm

Why is that important to life?


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The tendency of

molecules of the

same kind to stick toone another is called

cohesion.

The type of attractionthat occurs between

unlike molecules is

called adhesion.

(van der Waals forces)


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H

ydrogen Bonding1.Adhesion = H2O sticks to things

2.Cohesion = H2O sticks to itself

3. : Why important to life?

ickTime and aT FF ncompressed decompressor

are needed to see this pict re.


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Answer:1. Stable liquid

2. Climbs up xylem in plants againstgravity

3. H bond - easily broken - changesstate easily

Applied: Insects/geckos stick tothings

4. Drops of water

Ex. Why ice expands


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Summary of water

properties

basic biochemistry 2010,part 1

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