ACTIVITY 1

Question 1

most biochemical reactions take place in an _______ environment

Answer 1

aqueous environment

Question 2

is the active participant in many biochemical reaction and thus, it makes up about 70% of the human body and the other animals

Answer 2

water

Question 3

all biological proccesses are affected by the _______ or ________ of the medium in which they occur

Answer 3

acidity or alkalinity

Question 4

may affect the conformation and structures of substances and the concentration of molecular and charged species;

this can affect the transport of substances through membranes and the efficiency of enzymes

Answer 4

The H+ concentration of an aqueous solution

Question 5

Body mechanisms to maintain pH

Answer 5

1. buffer systems of the body
2. the action of the kidneys in which acids and bases are excreted in urine
3. respiratory mechanisms in which H+ ion concentration in the body fluids is regulated by the rate of CO2 elimination in the lungs

Question 6

is one that resists drastic changes in H+ concetration when small amounts of acid or bases are added;

is made up of their weak acids and their salts or weak bases and their salts

Answer 6

buffer solution

Question 7

The H+ concentration is conveniently expressed in terms of

Answer 7

pH

Question 8

The pH of a buffer solution made up of a weak acid and its salt can be calculated with the use of the _______ also know as the _________

Answer 8

Henderson-Hasselbach equation; buffer equation

Question 9

is the negative logarithm of the ionization constant of the weak acid

Answer 9

pKa

Question 10

is equal to 14 at 25 degrees celcius

is the negative logarithm of the ionization constant of water

Answer 10

pKw

Question 11

is the negative logarithm of the ionization constant of the base

Answer 11

pKb

Question 12

the buffer system of the body are made up of (3)

Answer 12

weak acid and their salts as well as proteins

Question 13

give the Ph and the buffer systems of Blood plasma (salt/acid)

Answer 13

pH: 7.4
Buffer systems:
HCO3^-1 / H2CO3,
HPO4^2/H2PO4-

Question 14

give the Ph and the buffer systems of Red Blood cells (salt/acid)

Answer 14

pH: 7.2
buffer systems:
HCO3^-1/H2CO3,
Hb-/HHb,
HbO2-/HHbO2-

Question 15

give the Ph and the buffer systems of Spinal fluid (salt/acid)

Answer 15

pH: 7.4
buffer:
HPO4^-2/H2PO4-,
Proteinate-/ H proteins,
HCO3-/H2CO3

Question 16

give the Ph and the buffer systems of urine (salt/acid)

Answer 16

pH: 4.8 - 7.4
buffer:
HPO4^2- / H2PO4-,
Org.acid- / H Org.acid

Question 17

are primary importance in regualting the pH of the fluids and tissues of living organisms within the limits consistent with life and normal function.

are widely employed in the laboratory to control the pH ofculture media for microorganisms and tissues.

Answer 17

Buffers

Question 18

are also used for many chemical reactions requiring controlled pH including those catalyzed by enzymes.

Answer 18

buffers

Question 19

the use of buffers is an important part of many industrial processes like fermentation, electroplating, manufacture of leather, photographic materials, and dyes.

T or F : )

Answer 19

T

Question 20

Why do we need to choose the weak acid whose pKa is closest to the desired pH?

Answer 20

to insure maximum buffer capacity

Question 21

You need to consider the individual concentration of the buffer salt and acid needed to obtain a suitable buffer capacity. Concetration ranges from _____ to _____. Buffer capacity ranges from ______ to ______.

Answer 21

Concentration range: 0.05 M - 0.50 M
Buffer capacity range: 0.01 M - 0.10 M

Question 22

What is the satisfactory pH range of buffer equation?

Answer 22

4 to 10