Biochem: Chapter 1 - Exam 1

If the pH > pKa = pronation or depronation?

depronation

If the pH < pKa = pronation or depronation?

pronation

What are the major acidic groups of biomolecules?

Carboxyl, phosphate ester, phodiester, sulhydryl, phenolic hydroxyl

Which of the major acidic groups would you expect to depronante (neg charge) at pH 7?

Carboxyl, phosphate ester, phosphodiester

Which of the major acidic groups would you expect to depronante (neg charge) at pH well above 7?

sulfhydryl and phenolic hydroxyl

(carboxyl, phosphate ester, phosphodiester) tend to be deprotonated at pH 7 because their relevant pKa values are?

below 7

What are the most Important Basic Groups in Biomolecules

aliphatic amino, guanidino (in argine) and aromatic amines

What are the types of aliphatic aminos?

primary, secondary, and tertiary

of the basic groups of biomeolcules, which are pronated (+ charge) at a pH 7?

Aliphatic amino (primary, secondary, and tertiary) and Guanidino (in arginine)

of the basic groups of biomeolcules, which are pronated (+ charge) at a pH well below 7?

aromatic amines

in the blood plasma (outside the cell), what is the major cation?

Na+

in the blood plasma (outside the cell), what is the major anion?

Cl- (primarily)

HCO₃- is also important

in the interstitial (extracellular) fluid (outside the cell), what is the major cation?

Na+

in the interstitial (extracellular) fluid (outside the cell), what is the major anion?

Cl- (primarily)

HCO₃- is also important

in the intracellular fluid (inside the cell), what is the major cation?

K+

in the intracellular fluid (inside the cell), what is the major anion?

phosphates and proteins

Respiratory acidosis is caused by abnormal ______ of CO2 aka ______?

retention (too much stays in)

HYPOventelation

Respiratory alkalosis is caused by abnormal ______ of CO2 aka ______?

expulsion (too much comes out)

HYPERventilation

If there was an increase in alveolar ventilation, what would happen to the CO2? pH? What is this also called? Is this acidosis or alkalosis?

CO2 - too much would leave the body

pH - would increase

This is called hyperventilation

This is alkalosis (the blood is becoming more alkaline or basic)

If there was an decrease in alveolar ventilation, what would happen to the CO2? pH? What is this also called? Is this acidosis or alkalosis?

CO2 - too much would accumulate the body

pH - would decrease

This is called hypoventilation

This is acidosis (the blood is becoming more acidic)

metabolic ____ is caused by the abnormal loss of acids from the body. What would be the cause of this?

alkalosis; abnormal loss of acids from the body (like in excessive vomiting).

metabolic _____ is caused by the abnormal gain of acids from the body. What would be the cause of this

acidosis; overproduction/accumulation of organic salts

What are the three lines of defense when blood pH is abnormal?

1. The buffer systems act immediately to prevent excessive fluctuations of the blood pH.

2. Alveolar ventilation increases in acidosis and decreases in alkalosis.

3. The kidneys excrete excess H+ in acidosis and excess HCO3– in alkalosis.

of the three lines of defense to restore a normal pH, which is the long term mechanism that acts on a time scale of hours to days? 

3. The kidneys excrete excess H+ in acidosis and excess HCO3– in alkalosis.

How can you distinguish respiratory acidosis and metabolic acidosis?

Measure total carbon dioxide (CO₂ + H₂CO₃ + HCO₃^– ) in the plasma

Respiratory _______ → ↑ total CO₂ → CO₂ retention from hypoventilation

As CO₂ goes up, what happens to the pH?

acidosis

As CO2 goes up, pH goes down - inverse relation (opposite)

Respiratory _____ → ↓ total CO₂ → excessive CO₂ loss from hyperventilation

As CO₂ goes down, what happens to the pH?

alkalosis

As CO₂ goes down, pH goes up - inverse relation (opposite)

Metabolic _______ → ↓ total CO₂ → ↓ HCO₃⁻ from bicarbonate loss or acid gain

As total CO₂ and HCO₃^- goes down, what happens to the pH?

acidosis

As total CO₂ and HCO₃^- goes down, the pH also decreases (same direction)

Metabolic _______ → ↑ total CO₂ → ↑ HCO₃⁻ from bicarbonate gain or acid loss

As total CO₂ and HCO₃^- goes up, what happens to the pH?

alkalosis

As total CO₂ and HCO₃^- goes up, the pH also increases (same direction)

_________: CO₂ causes the problem.

Respiratory

________: HCO₃⁻ causes the problem.

Metabolic

what are the major types of isomers?

constitutional, geometric, and optical

________ Isomers - Isomerism between structures differing in constitution and described by different line formulae

Constitutional

Constitutional isomers vs structural isomers vs Positional isomers

• Constitutional = structural: same molecular formula, different connectivity

• Positional: same molecular formula, but a functional group/substituent is located at a different position on the same basic carbon skeleton:

All positional isomers are constitutional isomers, but not all constitutional isomers are positional isomers.

________ Isomers Are Specific Cases of Constitutional Isomerism 

Positional

CH₃OCH₃ and CH₃CH₂OH are examples of ___________ isomers

constitutional

what kind of isomers are the following?

constitutional - Both have the same molecular formula but their atoms are connected differently.

Which pair of molecules are constitutional isomers?

A. CH₃CH₂OH and CH₃OCH₃
B. CH₃CH₂OH and CH₃CH₂OH
C. CH₄ and C₂H₆
D. H₂O and H₂O₂

Answer: A. CH₃CH₂OH and CH₃OCH₃

Why: Both have the same molecular formula (C₂H₆O), but their atoms are connected differently.

What kind of isomers are the following?

Molecule 1:
CH₃—CH₂—OH

Molecule 2:
CH₃—O—CH₃

constitutional isomers

Why: Both have the molecular formula C₂H₆O, but the atoms are connected differently.

what kind of isomers are the following:

Molecule 1:
CH₃—CH₂—CH₂—CH₃

Molecule 2:

CH₃

|

CH₃—CH—CH₃

constitutional isomers

Both have the molecular formula C₄H₁₀, but the atoms are connected differently.

• Molecule 1 → straight carbon chain

• Molecule 2 → branched carbon chain

Same molecular formula + different connectivity = constitutional isomers.

what kind of isomers are the following:

2-phosphoglycerate and 3-phosphoglycerate are positional isomers — which means they are also constitutional/structural isomers.

• 2-phosphoglycerate: phosphate group is attached to carbon 2

• 3-phosphoglycerate: phosphate group is attached to carbon 3

The molecules have the same molecular formula and the same basic carbon skeleton, but the phosphate group is connected at a different position.

what kind of isomers are the following:

Glyceraldehyde and dihydroxyacetone are constitutional (structural) isomers, but they are not usually classified as positional isomers.

They have the same molecular formula: C₃H₆O₃, but they have different functional groups:

what kind of isomers are the following:

constitutional isomers

what properties differ in constitutional isomers?

Have different chemical, physical and biological properties

________ isomers differ in the positions of functional groups within the molecule

Positional

_______ isomers differ in the arrangement of substituents at a rigid portion of the molecule. (Functional groups identical, differ in arrangement of substituents at a rigid portion of the molecule) A typical example involves the cis-trans isomers of carbon-carbon double bonds

Geometric

what type of isomer is the following?

geometric isomers

what type of isomer is the following?

geometric isomers

Which pair represents geometric isomers?

A. cis-2-butene and trans-2-butene
B. 1-butene and 2-butene
C. butane and isobutane
D. ethanol and dimethyl ether

A. cis-2-butene and trans-2-butene

Why: Geometric isomers have the same molecular formula and same connectivity, but differ in the arrangement of groups around a double bond.

• cis = similar groups are on the same side

• trans = similar groups are on opposite sides

Which structure pair can exist as cis/trans geometric isomers?

A. CH₂=CH₂
B. CH₃—CH=CH—CH₃
C. CH₃—CH₂—CH₃
D. CH₂=CH—CH₃

B. CH₃—CH=CH—CH₃

Why: Each carbon of the double bond must have two different groups attached.

Why does this molecule not have geometric isomers?

CH₂=CH—CH₃

A. It does not contain carbon
B. It has only single bonds
C. One carbon of the double bond has two identical groups
D. The molecule is too small

C. One carbon of the double bond has two identical groups

what properties differ in geometric isomers?

Have different chemical, physical and biological properties

______ Isomers - Enantiomers → chirality

Functional groups identical, differ in the orientation of substituents around an asymmetrical carbon (a carbon with

four different substituents.)

Optical

If the molecule has only one asymmetric carbon, the isomers are ______ images (called enantiomers)

They are related to each other in the same way as the left hand and the right hand; therefore optical isomerism is also called ____

mirror; chirality