Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry > Chapter 1 : pH and Buffers > Flashcards

Chapter 1 : pH and Buffers Flashcards

1
Q

Types of Chemical Bonds

A
  • Ionic
  • Covalent & Polar covalent
  • Hydrogen
  • Van der Waals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What type of bond is water ?

A

Polar Covalent .

The oxygens have a slight (-) charge while the hydrogens have a a slight (+) charge creating a difference in charge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the universal law for solvents

A

” Like dissolves like”

polar molecules dissolve in polar solvents vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Ionic compounds can create crystal structures called

A

Salts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why do salts dissolve easily in water?

A

The positive part of water molecules attracts the negative chloride ions and the negative part of water molecules attracts the positive sodium ions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Water has the highest interaction with what type of molecule ?

A

Polar molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why do water molecules create “ cages” around non-polar molecules ?

A

Non- polar molecules

(CH bonds ) usually have no charge. Thus hydrogen bonds with itself to surround the molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

In a low entropy state , water molecules are

A

highly ordered and structured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In high entropy states,water molecules are

A

less ordered and structured. Most are freely moving

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is an amphiphilic molecule ?

A

Molecules that are both polar and non-polar

Ex: fatty acids, phospholipids, micelles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are fatty acids amphiphilic ?

A

The tails are nonpolar with CH bonds and the heads are polar with the hydrogen bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why is the polarity of phospholipids so important

A

It helps to form the extracellular matrix or cell transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

H+ can also be represented as

A

H3O (+)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In acidic conditions , hydronium ions combine to form

A

H(+) + H20 -> H30(+)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In basic conditions, hydronium ions combine to form

A

H20 -> H(+) + OH (-)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the concentration of H+ at equilibrium ?

A 
H+ = 1 x 10 ^(-7) M 
OH = 1 x 10 ^(-7) M
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the concentration of H+ at acidic conditions?

A

H+ is greater than 1 x 10 ^(-7) M

OH is less than 1 x 10 ^(-7) M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the concentration of H + at basic conditions ?

A

OH is greater than 1 x 10 ^(-7) M

H(+) is less than 1 x 10 ^(-7) M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The Keq constant always adds up to

A

1 x 10 ^(-14) M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the Keq constant equation for water ?

A

Keq = [ H+] [OH-] ÷ [H20]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is Kw

A

Kw = ionization of water constant which is 1 x 10 ^(-14) M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is pH

A

ratio of H+ concentration vs OH- concentration. It is also based on the logarithmic scale.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the logarithmic equation for pH ?

A

pH = (-)log10[H+]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are electrolytes ?

A

substances that when dissolved in water, conducts an electric current

25
Q

Examples of of electrolytes

A
  • Salts ( NaCl )
  • Strong acids (HCL)
  • Strong bases
    ( NaOH )
26
Q

What is the general equation for Keq

A

Products/ Reactants

27
Q

What is Ka

A

The acid disassociation constant

28
Q

What is the Ka equation ?

A

Ka = [H+] [A-] ÷ [HA]

29
Q

True or false, weak electrolytes dissociate completely

A

False

30
Q

Examples of weak electrolytes

A

Nitric acid : HNO3

Acetic acid : CH3COOH

31
Q

The higher the Ka….

A

The more the compound disassociates. The pKA is also inversely lower

32
Q

Henderson Hasselbalch equation

A

pH = pKA - log

( [HA]/ [A] )

33
Q

What does the Henderson Hasselbalch equation tell us ?

A
  • the relationship between the dissociation of weak acid and pH
  • helps to calculate the pH or pKA
34
Q

If half the acid is disassociated,

A

[HA] =[ A] or pH= pKA

35
Q

What is titration ?

A

A method used to determine the amount of acid in a solution by adding incremental amounts of base .

36
Q

What happens when more base is added to a solution

A

More OH combines with H+ causing more acid disassociation from the water formation . pH increases.

37
Q

Where is the halfway point in a titration curve

A

Where the pH= pKA

or the flat line in the middle of the graph

38
Q

The higher the pKA ,..

A

the lower the Ka , and the harder it is for H+ to dissociate

39
Q

Polyprotic acids

A

Acids that have more than one H+ to lose . On the titration cure , each flat line indicates when an H+ is lost

40
Q

Examples of Polyprotic acids

A

H3PO4 - phosphoric acid

H2SO4 - sulfuric acid

41
Q

What is a buffer

A

Something used to help maintain solutions within a certain pH range by absorbing excess H+ or OH

42
Q

The pH range for a buffer is around the

A

pKA

43
Q

What is a common buffer used in intracellular fluid

A

Phosphate is used in the body as it is used for cellular transport

44
Q

What is another example of a buffer system in the body

A

Histidine buffer system ( amino acid)

45
Q

What is the buffer system used in blood circulation

A

Bicarbonate buffer system from carbonic acid ( H2CO3) to bicarbonate ( HCO3)

46
Q

What is the 1st law of thermodynamics ?

A

Energy cannot be created or destroyed, simply conserved and transformed

47
Q

The change in internal energy of a system is equal to

A

the amount of energy absorbed by the system in the form of heat and the work performed on the system through its surroundings

48
Q

Energy Conservation Equation

A

ΔE = q + w

Energy is equal to the total amount of heat and work

49
Q

What is enthalpy

A

The total amount of heat or energy in a system . Or change of energy in a reaction.

50
Q

In chemical and biochemical reactions, pressure is

A

constant

51
Q

What is the 2nd law of thermodynamics

A

Systems tend to proceed from ordered ( low entropy) to disordered ( high order)

52
Q

What is entropy(S) ?

A

The measure of disorder and randomness in a system

53
Q

Reactions are more likely to occur if they

A

involve large changes in entropy or (-) S

54
Q

What is Gibb’s Free Energy

A

Compares the changes in enthalpy and the changes in entropy at a given temperature to predict if a reaction will continue spontaenously or not

55
Q

Equation for Gibbs Free Energy

A 
ΔG° =  ΔH° - TΔS°
ΔG° = Gibbs free energy 
ΔH° = Enthalpy 
T = Temperature in K 
ΔS = Entropy
56
Q

If ΔG° is negative

A

Exergonic reaction, releases energy , spontaneous , proceeds in the forward direction

57
Q

If ΔG° is positive

A

Endergonic reaction , reaction is non spontaneous and proceeds in the reverse reaction

58
Q

If ΔG° is zero

A

Equilibrium

Biochemistry (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions