Trace elements? 25 elements essential for life. Symptom of an iodine deficiency Iron deficiency?

Trace elements?

25 elements essential for life

Symptom of an iodine deficiency

Iron deficiency?

Locations and charges of protons?Neutrons?Electrons?

Atomic number

Atomic mass

Atomic Mass vs. Atomic Number?????

What is an isotope?

Cancerous throat tissue

Isotopes use to diagnose disease

Administer a molecule similar to glucose that has a radioactive tag

PET scan picks up the released radiation and detects areas of high metabolism

Urea Breath TestTests for stomach bacteria: Helicobacter pylori

Give urea with some of the carbon being 14C.

If there is Helicobacter pylori in the stomach, then this bacteria will break down the urea and produce C02.

The CO2 will be exhaled by the patient and collected in a balloon.

If some of the carbon in the exhaled CO2 contains is 14C then there must be some bacteria present in the stomach.

The more 14C exhaled, the more Helicobacter pylori present.

The breath test can be repeated to determine the success of the treatment.

Radioactive iodine

Used treat hyperthyroidism and thyroid cancer,

Small doses used to test thyroid function.

shows the concentration of radioactive tracer bound to monoamine oxidase B (MAO B). Red shows the highest concentration.

MAO B is important because it breaks down the chemicals that allow nerve cells to communicate and regulate blood pressure.

What causes an atom to react with other atom? Or… would cause it to be nonreactive (stable)?

Ionic Bond

(–) (–)

O

HH

(+) (+)

Hydrogen bond

Strong attraction for electrons

• A few water molecules can break apart into ions– hydrogen ions (H+)– hydroxide ions (OH–)

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pH

• Acids vs. bases

Copyright © 2009 Pearson Education, Inc.

pH

• A pH scale (pH = potential of hydrogen) is used to describe whether a solution is acidic or basic– pH ranges from 0 (most acidic) to 14 (most basic)– A solution that is neither acidic or basic is neutral

(pH = 7)

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Acidic solution

pH scale

Battery acid

0

1

2

3

4

5

Lemon juice, gastric juice

Grapefruit juice, soft drink,vinegar, beer

Tomato juice

Rain water

Human urine

Saliva

Pure water

6

7

Human blood,tears

Seawater

8

9

10

11

12

13

Milk of magnesia

Household ammonia

Household bleach

Oven cleaner

Neutral solution

Basic solution

NEUTRAL[H+]=OH–]

Incr

ea

sin

gly

AC

IDIC

(Hig

he

r c

on

cen

tra

tio

n o

f H

+)

14

Incr

ea

sin

gly

BA

SIC

(Lo

we

r c

on

cen

trat

ion

of

H+)

Logarithmic scaleChange in one

unit on pH scale = 10 x change in hydrogen ion concentration

Solution A has a pH = 4Solution B has a pH = 2

How much more acidic is Solution B?

Solution C has a pH = 9Solution D has a pH = 12

How much more H+ ions does solution C have compared to solution D?

Why is pH important?

• Different areas of the body have different pH values– Ex: stomach

blood

• If the pH varies from this value, proteins lose their shape and don’t work

Molecules that can accept or release H+ resist change in pH

Are usually weak acid/base pairs

Cohesion of water water sticking to itself• Does this

because of hydrogen bonding

• Results in water having surface tension– “film” on top of

water

Temperature moderation

Water resists changes in temperature

Feb: 15.7° FJuly: 70.4 ° F

Feb: 44.3° FJuly: 65.3 ° F

Water can absorb and release a lot of thermal energy with a small change in temperature

-ex: moderate temperatures at coasts

Absorbs a lot of energy when heating up

Releases energy when cooling down

ex: evaporative cooling

Adhesion water sticking to something else(polar or charged)

Meniscus

Transpiration

• Uses cohesion and adhesion to move water from the roots to top of a tree

Adhesion of waterTo cells of xylem

Cohesion of water to itself

Density Water is densest at 4° C

Ice is less dense than liquid water

Provides insulation and allows wildlife to survive under a layer of ice

Ice floats

Water is an almost universal solvent

Ionic compounds (like salt) will dissolve in water

Polar molecules will dissolve in water(sugar)

In a solution the SOLVENT is the substance in a greater amount

The SOLUTE is the substance present in a lesser amount

Glucose

Molecules that can accept or release H+ resist change in pH

Are usually weak acid/base pairs