Lecture 2

Question 1

Primary elements

Answer 1

C, H, O, N

Question 2

life is based on what element?

Answer 2

life is carbon based

carbon is the backbone of life

Question 3

What is the most common element in the body?

Answer 3

more than 99% of atoms in the body are H

O is next

Question 4

Secondary elements

Answer 4

P- phosphorus

S- sulfur

Question 5

Ions/electrolytes

Answer 5

Na+
K+
Cl-
Ca2+

Question 6

Trace elements

Answer 6

things like coblat, iron magnesium

Question 7

Covalent bonds

Answer 7

strongest
combination of 2 or more atoms that share electrons
polar and non polar
ex: C-C

Question 8

Ionic bonds

Answer 8

weaker than covalent
2 ions one + and one -
Na+—Cl-

Question 9

Hydrogen bonds

Answer 9

Weaker than ionic and covalent
many together can be strong
-OH—OH

Question 10

Hydrophobic interactions

Answer 10

weakest

-CH—HC

Question 11

Bonds in water

Answer 11

Has polar covalent bonds between H and O

hydrogen bonds are formed between adjacent water molecules

Question 12

Characteristics in water

Answer 12

water is a polar solvent - dissolves polar and charged molecules
water is the physiological medium - ICF and ECF are aqueous solutions
water is a reactant / product of hydrolysis and dehyration reactions

Question 13

surface tension

Answer 13

attractive force between water molecules that cause water to form spherical droplets
caused by hydrogen bonding

Question 14

anions vs cations

Answer 14

anions negatively charged ions

cations positively charged ions

Question 15

polar

Answer 15

electrons shared unequally 
dissolves in water 
ex: O-H
O-C
N-H
N-C
H2O
NH3
CO2

Question 16

non polar

Answer 16

insoluble in water 
electrons are shared equally 
ex: C-C (same thing bound together)
C-H
O=O

Question 17

Organic molecules

Answer 17

carbon based molecules
4 types of covalent bonds - single bonds, double bonds, chains, and rings
structural “backbone” of biological molecules

Question 18

Hydrocarbons

Answer 18

contain only C-H and C-C bonds

Question 19

Hydroxyl

Answer 19

-OH
alcohols and sugars
Polar

Question 20

carboxyl

Answer 20

-C=O
|
OH

organic acids
Polar, acidic, negatively charged
-COOH -> H+ + -COO-

Question 21

Amino

Answer 21

-NH2
amines
polar, basic, positively charged
-NH2 + H+ –> -NH3+

Question 22

Phosphate

Answer 22

organic phosphates

acidic, negatively charged

Question 23

acids and base are…

Answer 23

compounds that exchange H+ ions in aqueous solutions

Question 24

acid

Answer 24

H+ donor / released H+ into solution (proton donor)

Increase H+ and decreases pH

Question 25

Base

Answer 25

H+ acceptor/removes H+ from solution (proton acceptor)

decreases H+ increases pH

Question 26

Buffer

Answer 26

mixture of molecules that minimizes changes in [H+]
stabilizes pH
physiological buffers: bicarbonate, phosphate, proteins

Question 27

pH scale

Answer 27

each # on the pH scale is a 10 fold difference

inverse relationship= higher the pH lower the [H+]

Question 28

acidity of a solution

Answer 28

depends on amount of free H+

more free H+ the more acidic the solution

Question 29

Buffered solution means

Answer 29

less change in pH