CHEM10050 : Guiry Lecture 16 - Esters and Triacylglycerols

Which reducing agent is used to reduce esters?

a) LiAlH4

b) NaBH4

c) H2SO4

d) HCl

a) LiAlH4

What products are obtained when esters are reduced using LiAlH4?

a) Carboxylic acid and alcohol

b) Alcohol and aldehyde

c) Two alcohols

d) Alkene and alcohol

c) Two alcohols

Which of the following is the reverse of ester formation?

a) Ester hydrolysis using LiAlH4

b) Ester hydrolysis using NaBH4

c) Esterification using HCl

d) Ester hydrolysis using H+ catalyst

d) Ester hydrolysis using H+ catalyst

What happens to the equilibrium when excess water is added in the hydrolysis of esters?

a) Shifts to the left

b) Shifts to the right

c) Remains unchanged

d) Completely stops

b) Shifts to the right

Which type of hydrolysis of esters is irreversible?

a) H+ -catalysed hydrolysis

b) Base-mediated hydrolysis

c) Neutral hydrolysis

d) Acidic hydrolysis

b) Base-mediated hydrolysis

What is the product of base-mediated hydrolysis of esters?

a) Carboxylic acid and alcohol

b) Carboxylate salt and alcohol

c) Alkene and alcohol

d) Carboxylate salt and aldehyde

b) Carboxylate salt and alcohol

Which of the following is true about the solubility of low molecular weight esters in water?

a) They are insoluble in water

b) They are soluble in water

c) Their solubility depends on their boiling point

d) They only dissolve in hot water

b) They are soluble in water

What is the boiling point of esters compared to their parent carboxylic acids?

a) Higher

b) Lower

c) Same

d) Depends on the size of the alkyl chain

b) Lower

What functional group is bonded to the carbonyl carbon in esters?

a) Alkene

b) Alcohol

c) Amine

d) OR group

d) OR group

What type of hydrolysis of esters is used in the production of soap?

a) Acidic hydrolysis

b) Neutral hydrolysis

c) Base-mediated hydrolysis

d) H+ -catalysed hydrolysis

c) Base-mediated hydrolysis

What is the main component of animal fat?

a) Triglycerides

b) Fatty acids

c) Esters

d) Carbohydrates

a) Triglycerides

What is the function of enzyme-catalysed ester hydrolysis in our body?

a) To store energy

b) To produce energy

c) To synthesise proteins

d) To remove waste products

b) To produce energy

What is the final product of the breakdown of fatty acids?

a) Citric acid

b) Acetyl Coenzyme A

c) ATP

d) Glucose

b) Acetyl Coenzyme A

How many kcal/g do fatty acids yield?

a) Less than carbohydrates

b) The same as carbohydrates

c) Twice as many as carbohydrates

d) More than twice as many as carbohydrates

d) More than twice as many as carbohydrates

Why do saturated fatty acids have higher melting points compared to unsaturated fatty acids?

a) They pack efficiently into crystals

b) They contain fewer carbon atoms

c) They have more double bonds

d) They are more polar

a) They pack efficiently into crystals

What happens to the melting point of fatty acids as the number of double bonds increases?

a) It increases

b) It decreases

c) It stays the same

d) It depends on the length of the fatty acid chain

b) It decreases

Which type of fatty acids are typically used as cooking oils?

a) Saturated fatty acids

b) Monounsaturated fatty acids

c) Polyunsaturated fatty acids

d) Trans fatty acids

c) Polyunsaturated fatty acids

What is the process called when triacylglycerols are hydrolysed in aqueous base to form carboxylate salts and alcohols?

a) Saponification

b) Reduction

c) Esterification

d) Hydrogenation

a) Saponification

What is the purpose of soap made by heating animal fat with base?

a) To moisturize the skin

b) To provide energy

c) To remove dirt and oil from surfaces

d) To sterilize surfaces

c) To remove dirt and oil from surfaces

What type of bonds are present in unsaturated fatty acids?

a) Single bonds only

b) Double bonds only

c) Both single and double bonds

d) Triple bonds

b) Double bonds only

What is the main reason biodiesel is becoming an attractive alternative to conventional diesel?

a) Economic and environmental reasons

b) Aesthetic reasons

c) Efficiency reasons

d) Availability reasons

a) Economic and environmental reasons.

What percentage of greenhouse emissions are caused by 'Transport' in the EU?

a) 5%

b) 10%

c) 25%

d) 50%

c) 25%.

What is the EU directive required for fuels to come from biofuels by 2020?

a) 5%

b) 10%

c) 20%

d) 30%

c) 20%.

What is the main omega-3 fatty acid that cannot be synthesized by humans?

a) 𝛼-linoleic acid (ALA)

b) Eicosapentaenoic acid (EPA)

c) Docosahexaenoic acid (DHA)

d) Oleic acid

a) 𝛼-linoleic acid (ALA).

What is the dietary source for omega-3 fatty acids?

a) Meat and poultry

b) Nuts and seeds

c) Fish oil and flax

d) Dairy products

c) Fish oil and flax.

What is the acceptable intake for men and women for omega-3 fatty acids per day?

a) 1.0 g/day for men and 0.8 g/day for women

b) 1.4 g/day for men and 1.0 g/day for women

c) 1.6 g/day for men and 1.1 g/day for women

d) 2.0 g/day for men and 1.5 g/day for women

c) 1.6 g/day for men and 1.1 g/day for women.

What is the current industrial process for biodiesel production?

a) Oxidation of fatty acids

b) Hydrogenation of triglycerides

c) Esterification of triglycerides

d) Fermentation of carbohydrates

c) Esterification of triglycerides.

What are the main sources of organophosphate esters and anhydrides?

a) Chemicals and polymers industry

b) Pharmaceutical industry

c) Biology

d) Food/health industry

c) Biology.

Which type of fatty acid interferes with efficient packing and lowers the melting point?

a) Saturated fatty acids

b) Monounsaturated fatty acids

c) Trans fatty acids

d) Polyunsaturated fatty acids

d) Polyunsaturated fatty acids.

Which of the following is NOT a type of phosphoric acid ester?

a) Monophosphate ester

b) Diphosphate ester

c) Triphosphate ester

d) Tetraphosphate ester

d) Tetraphosphate ester

Which of the following is a monophosphate ester?

a) Carboxylic acid

b) Part of a phosphoric acid

c) Part of a phosphoric ester

d) Both a) and b)

d) Both a) and b)

What is the reaction that forms a monophosphate ester?

a) Alcohol (ROH) + phosphoric acid → monophosphate ester

b) Carboxylic acid + phosphoric acid → monophosphate ester

c) Alcohol (ROH) + diphosphoric acid → monophosphate ester

d) Carboxylic acid + diphosphoric acid → monophosphate ester

a) Alcohol (ROH) + phosphoric acid → monophosphate ester

What is the most energy-rich substance?

a) ATP

b) ADP

c) Phosphoric acid

d) Triphosphoric acid

a) ATP

How much energy is generated from the reaction of 1 mol of ATP and 1 mol of ADP?

a) 20 kJ (4.8 kcal)

b) 30 kJ (7.3 kcal)

c) 40 kJ (9.7 kcal)

d) 50 kJ (12.1 kcal)

b) 30 kJ (7.3 kcal)

What is the main source of energy in cells?

a) Glucose

b) Fatty acids

c) Amino acids

d) ATP

d) ATP

Which stage of food and energy metabolism involves the degradation of sugars, fatty acids, and amino acids in the cytoplasm of cells?

a) Stage one

b) Stage two

c) Stage three

d) Stage four

b) Stage two

What is the final product of the citric acid cycle?

a) Acetyl-CoA

b) ATP

c) CO2

d) NADH

c) CO2

Which reduced coenzyme is produced during the citric acid cycle?

a) NAD+

b) FADH2

c) NADH

d) ATP

b) FADH2

Which stage of food and energy metabolism involves the oxidation of acetyl-CoA inside the mitochondria?

a) Stage one

b) Stage two

c) Stage three

d) Stage four

c) Stage three

What is the process by which energy from reduced coenzymes is used to make ATP?

a) Electron transport

b) Oxidative phosphorylation

c) Glycolysis

d) Citric acid cycle

b) Oxidative phosphorylation

Which of the following is NOT a type of reduced coenzyme?

a) NAD+

b) NADH

c) FAD+

d) FADH2

c) FAD+

How much acceptable intake of w-3 fatty acids is recommended for women per day?

a) 1.6 g

b) 1.1 g

c) 2.0 g

d) 1.4 g

b) 1.1 g

What is an example of an omega-3 fatty acid?

a) Palmitic acid

b) Stearic acid

c) Oleic acid

d) 𝛼-linolenic acid

e) Arachidonic acid

d) 𝛼-linolenic acid (ALA)

How many kilojoules (kJ) are generated by 2 moles of ATP hydrolysis?

a) 15 kJ

b) 30 kJ

c) 60 kJ

d) 120 kJ

b) 30 kJ.