Lipids

Question 1

Lipids are compounds that are soluble in which type of solvents?
• A. Water
• B. Organic solvents such as acetone and ether
• C. Acidic solutions
• D. Salt solutions

Answer 1

B

Question 2

The primary storage site for lipids in the body is:
• A. Muscle tissue
• B. Liver
• C. Adipose tissue (fat cells)
• D. Pancreas

Answer 2

C

Question 3

What is the largest proportion of lipids consumed in the human diet?
• A. Phospholipids
• B. Cholesterol
• C. Triacylglycerols (TG)
• D. Free fatty acids

Answer 3

C

Question 4

Lipids serve as precursors for:
• A. Carbohydrates
• B. Enzymes
• C. Hormones and signaling molecules
• D. Nucleotides

Answer 4

C

Question 5

Which function is NOT associated with lipids?
• A. Energy storage
• B. Insulation of organs
• C. Cell membrane formation
• D. Acting as an enzyme

Answer 5

D

Question 6

Which type of lipids act as carriers for fat-soluble vitamins?
• A. Steroids
• B. Phospholipids
• C. Triacylglycerols (TG)
• D. Free fatty acids

Answer 6

C

Question 7

What is the main role of short-chain fatty acids (SCFAs)?
• A. They function as a structural component in cell membranes
• B. They act as a key energy source for colonic cells
• C. They aid in protein synthesis
• D. They act as neurotransmitters

Answer 7

B

Question 8

SCFAs are primarily produced by:
• A. The liver
• B. The pancreas
• C. The fermentation of dietary fiber by gut bacteria
• D. The stomach lining

Answer 8

C

Question 9

The three main short-chain fatty acids (SCFAs) include:
• A. Acetic, butyric, and propionic acids
• B. Stearic, oleic, and linoleic acids
• C. Palmitic, arachidonic, and linolenic acids
• D. Myristic, lauric, and eicosapentaenoic acids

Answer 9

A

Question 10

Which of the following is not an effect of SCFAs on the gastrointestinal (GI) tract?
• A. Increase pH in the colon
• B. Enhance colonic blood flow
• C. Promote differentiation of mucosal cells
• D. Provide energy for colonic cells

Answer 10

A

Question 11

How do SCFAs affect sodium (Na+) absorption in the colon?
• A. They inhibit Na+ absorption
• B. They stimulate Na+ absorption
• C. They replace Na+ with potassium (K+)
• D. They have no effect on Na+ absorption

Answer 11

B

Question 12

How do SCFAs help protect against colon cancer?
• A. They increase bile solubility
• B. They reduce bile solubility and promote calcium (Ca+) binding to bile acids and fatty acids
• C. They increase pH in the colon
• D. They promote cholesterol synthesis

Answer 12

B

Question 13

Which SCFA is the most important energy source for colonic cells?
• A. Acetic acid
• B. Butyric acid
• C. Propionic acid
• D. Linoleic acid

Answer 13

B

Question 14

SCFAs inhibit the synthesis of which compound in the liver?
• A. Glucose
• B. Bile salts
• C. Cholesterol
• D. Protein

Answer 14

C

Question 15

One of the effects of SCFAs is to:
• A. Reduce calcium binding
• B. Enhance immune function
• C. Decrease colonic blood flow
• D. Decrease water retention

Answer 15

B

Question 16

Lipids contribute to cell signaling by:
• A. Acting as structural components in the pancreas
• B. Carrying oxygen molecules
• C. Modulating metabolic and immune responses
• D. Absorbing toxins from the bloodstream

Answer 16

C

Question 17

What hormones are synthesized from lipids?
• A. Insulin and glucagon
• B. Cortisol and estrogen
• C. Epinephrine and norepinephrine
• D. Growth hormone and prolactin

Answer 17

B

Question 18

How do lipids insulate the body?
• A. By forming a protective protein layer
• B. By generating electrical impulses
• C. By storing water in fat cells
• D. By providing a layer of fat under the skin and around organs

Answer 18

D

Question 19

Which type of lipids are major components of cell membranes?
• A. Triacylglycerols
• B. Cholesterol
• C. Phospholipids
• D. Steroids

Answer 19

C

Question 20

The primary function of cholesterol in cell membranes is to:
• A. Act as an energy source
• B. Increase membrane fluidity and stability
• C. Store excess carbohydrates
• D. Synthesize digestive enzymes

Answer 20

B

Question 21

Lipids are stored for energy in the form of:
• A. Free fatty acids
• B. Cholesterol
• C. Triacylglycerols
• D. Phospholipids

Answer 21

C

Question 22

When carbohydrates are unavailable, the body primarily uses:
• A. Lipids for energy
• B. Proteins for energy
• C. Nucleic acids for energy
• D. Minerals for energy

Answer 22

A

Question 23

What is the role of phospholipids in digestion?
• A. They break down proteins
• B. They transport fat-soluble vitamins
• C. They act as an emulsifier in bile
• D. They digest carbohydrates

Answer 23

C

Question 24

How do SCFAs affect immune function?
• A. They increase inflammation
• B. They suppress immune cell production
• C. They enhance immune response and prevent harmful cell growth
• D. They have no effect on immunity

Answer 24

C

Question 25

Which of the following is NOT a function of lipids? • A. Transport of fat-soluble vitamins • B. Formation of cell membranes • C. Storage of amino acids • D. Insulation and organ protection

Answer 25

C

Question 26

What is the primary function triacylglycerols (TG) in the human body? * A. Structural support in cell membranes * B. Energy storage * C. Hormone synthesis * D. Transport of proteins

Answer 26

B

Question 27

Which of the following is NOT a function of lipids? * A. Insulation and padding of organs * B. Cell signaling * C. carbohydrate synthesis * D. Synthesis of hormones

Answer 27

C

Question 28

Which of the following is a characteristic of a saturated fatty acid? * A. Contains one or more double bonds * B. Contains only single bonds * C. Has a kinked structure * D. Liquid at room temperature

Answer 28

B

Question 29

The omega system of naming fatty acids starts counting from which end? * A. Carboxyl end * B. Methyl end * C. Hydroxyl end * D. Phosphate end

Answer 29

B

Question 30

Which essential fatty acid is classified as an ω-3 fatty acid? * A. Linoleic acid * B. Arachidonic acid * C. α-Linolenic acid * D. Palmitic acid

Answer 30

C

Question 31

Which fatty acid is considered 'not good' due to its role in promoting inflammation? * A. ω-3 fatty acid * B. ω-6 fatty acid * C. Trans-fatty acid * D. Short-chain fatty acid

Answer 31

B

Question 32

Trans-fatty acids are produced artificially through which process? * A. Hydrogenation * B. Fermentation * C. Esterification * D. Hydrolysis

Answer 32

A

Question 33

Which of the following is NOT an effect of trans-fatty acids? * A. Increases LDL cholesterol * B. Decreases HDL cholesterol * C. Lowers blood pressure * D. Induces inflammation

Answer 33

C

Question 34

Which of the following is NOT a short-chain fatty acid? * A. Acetic acid * B. Butyric acid * C. Linoleic acid * D. Propionic acid

Answer 34

C

Question 35

SCFAs are mainly produced in the gut through the fermentation of what? * A. Lipids * B. Dietary fiber * C. Proteins * D.Carbohydrates

Answer 35

B

Question 36

Which of the following id NOT a function of SCFAs in the GI tract? * A. Enhance colonic blood flow * B. Increase bile solubility * C. Provide energy for colonic cells * D. Inhibit hepatic cholesterol synthesis

Answer 36

B

Question 37

What is the ATP yield from triglycerides compared to glucose? * A. 32 ATP for TG, 106 ATP for glucose * B. 106 ATP for TG, 32 ATP for glucose * C. 64 ATP for TG, 48 ATP for glucose * D.48 ATP for TG, 106 ATP for glucose

Answer 37

B

Question 38

Where are triglycerides primarily stored in the human body? * A. Liver * B. Adipose tissue * C. Muscle cells * D.Red blood cells

Answer 38

B

Question 39

What makes phospholipids ideal components for cell membranes? * A. They are fully hydrophilic * B. They are amphiphilic * C. There are fully hydrophobic * D. They are electrically charged

Answer 39

B

Question 40

Cholesterol is mainly synthesized in which organ? * A. Heart * B. Liver * C. Kidney * D. Pancreas

Answer 40

B

Question 41

Which enzyme is the rate-limiting step in cholesterol synthesis? * A. Lipase * B. HMG-CoA reductase * C. ATP synthase * D.Phospholipase

Answer 41

B

Question 42

What is the main function of the enterohepatic circulation? * A. Transport fatty acids to muscles * B. Reabsorb bile salts * C. Store cholesterol in adipose tissue * D. Regulate glucose metabolism

Answer 42

B

Question 43

Which enzyme starts TG digestion in the mouth? * A. Pancreatic lipase * B. Lingual lipase * C. Gastric lipase * D. Bile salts

Answer 43

B

Question 44

What is the role of bile salts in lipid digestion? * A. Break down lipids into smaller droplets * B. Hydrolyze TG into free fatty acids * C. Transport lipids in the bloodstream * D. Convert fatty acids into glucose

Answer 44

A

Question 45

Which lipoprotein is responsible for transporting cholesterol to peripheral tissues? * A. HDL * B. LDL * C. VLDL * D. Chylomicrons

Answer 45

B

Question 46

Which lipoprotein removes excess cholesterol from cells and transports it to the liver? * A. HDL * B. LDL * C. VLDL * D. Chylomicrons

Answer 46

A

Question 47

What apoprotein is present in chylomicrons? * A. ApoB-100 * B. ApoB-48 * C. ApoA-I * D.ApoC-II

Answer 47

B

Question 48

What enzyme hydrolyzes TG in chylomicrons? * A. HMG-CoA reductase * B. Lipoprotein lipase * C. Pancreatic lipase * D. Phospholipase A2

Answer 48

B

Question 49

Which protein is responsible for degrading LDL receptors, leading to increased LDL in circulation? * A. PCSK9 * B. ApoA-I * C. CD36 * D. Niemann-Pick Type C

Answer 49

A

Question 50

Which of the following lipids serves as a precursor for bile acids? * A. Phospholipids * B. Cholesterol * C. TG * D. Fatty acids

Answer 50

B

Question 51

Which of the following conditions can result from an imbalance of ω-6 to ω-3 fatty acids in the diet? * A. Increased risk of cardiovascular disease * B. Decreased inflammatory response * C. Enhanced insulin sensitivity * D. Increased HDL cholesterol levels

Answer 51

A

Question 52

Which if the following correctly describes the function of Niemann-Pick Type C protein in lipid absorption? * A. It hydrolyzes TG in chylomicrons * B. It facilitates the absorption of cholesterol into enterocytes * C. It transport bile salts into circulation * D. It regulates the rate of lipid oxidation into mitochondria

Answer 52

B

Question 53

During lipid digestion, what happens to long-chain fatty acids after entering the enterocyte? * A. They are directly absorbed into the bloodstream * B. They are converted into TG and packed into chylomicrons * C. They are stored into the cytoplasm of enterocytes * D. They are used immediately as an energy source

Answer 53

B

Question 54

Which of the following lipoproteins is formed in the liver and delivers endogenous lipids to peripheral tissues? * A. Chylomicrons * B. HDL * C. VLDL * D. LDL

Answer 54

C

Question 55

Which statement below is correct? * A. 18:2 Δ9,12 is an ω-9 fatty acid. * B. Saturated fat is liquid at room temperature * C. Hydrogenated fats are always saturated * D. Fatty acids are attached to glycerol by ester bonds * E. Saturated fat is the main component of canola oil

Answer 55

D

Question 56

Which statement below is correct? * A. Essential fatty acids belong to the ω-3 family. * B. Phospholipids are transported on the surface of lipoproteins. * C. Desaturates transform single bonds into double bonds. * D. Trans-fatty acids make fat less creamy. * E. LDL particles contain ApoB-48

Answer 56

B

Question 57

Choose the incorrect statement below? * A. A diet rich in ω-6 fatty acids limits the production of eicosanoids. * B. Heart, muscle, and adipose tissue require LPL to extract fatty acids from VLDL and chylomicrons. * C. Co-lipase supports TAG hydrolysis in the duodenum. * D. Chylomicron remnants and IDLs are disassembled in the liver. * E. The sterol nucleus is the basis for Vitamin D synthesis.

Answer 57

A

Question 58

Which lipoprotein sequence below contains the highest to lowest phospholipid content relative to its mass? * A. Chylomicron > VLDL > LDL * B. HDL > Chylomicron > LDL * C. LDL > HDL < Chylomicron * D. HDL > VLDL > Chylomicron * E. HDL > LDL > Chylomicron

Answer 58

E

Question 59

Which is not a feature of HMG-CoA reductase? * A. Its activity is regulated by intracellular cholesterol levels. * B. Converts HMG-CoA into mevalonate. * C. Is highly abundant in hepatocytes. * D. Is rate-limiting for endogenous cholesterol production. * E. Is the first enzyme in the endogenous cholesterol synthesis.

Answer 59

E

Question 60

Which statement below is true? * A. PCSK9 enhances cholesterol uptake by hepatocytes. * B. HDL interacts with LDL to collect triglycerides. * C. Cholesterol esters are formed in HDL by LCAT. * D. Chylomicrons contain ApoB-100. * E. Apo C-II is not necessary for VLDL to unload its cargo.

Answer 60

C

Question 61

What is the function of LCAT? * A. To esterify cholesterol moving from non-hepatic tissues into HDL * B. To convert cholesterol into triglycerides within HDL particles * C. To promote Apo-CII induced LPL activation * D. To transfer cholesterol esters from hepatocytes to the HDL particle * E. To allow the transfer of cholesterol from HDL to LDL particles

Answer 61

A

Question 62

In which of the following situations would someone be in the negative nitrogen balance? * A. When you are on a hypercaloric diet * B. Pregnancy * C. Disease states like sepsis or cancer * D. When you are trying to build muscle mass * E. None of these statements are correct

Answer 62

C

Question 63

Which statement below is correct? * A. HDL becomes spherical after interacting with non hepatic tissues * B. LCAT converts cholesterol into cholesterol esters within HDL particles * C. All options are correct * D. Nascent HDLs are small and discoidal particles * E. HDL particles pick up cholesterol from other lipoproteins and peripheral tissues

Answer 63

C

Question 64

Which statement below is incorrect? * A. Pepsin is responsible for digesting proteins in the stomach * B. Bicarbonate is secreted by the pancreas * C. HCl denatures pepsinogen in the stomach causing it to unfold and become activated * D. Secretin stimulates the release of bicarbonate into the small intestine * E. Trypsin and chymotrypsin are activated in the small intestine and work to break down peptide bonds in chyme

Answer 64

C

Question 65

Which below are effects of short chain fatty acids? * A. Promote peristalsis * B. Enhance cholesterol synthesis by the liver * C. Increase fecal volume * D. Enhanced colonic blood flow * E. Reduce bile acid excretion

Answer 65

D

Question 66

Which fatty acids below are associated with increased LDL and reduced HDL? * A. Short chain fatty acids * B. Omega 6 fatty acids * C. Cis fatty acids * D. Omega 3 fatty acids * E. Trans fatty acids

Answer 66

E

Question 67

Which statement below is correct? * A. PCSK9 is released when hepatic cholesterol content is low * B. Interstitial fluid accounts for the majority of the extracellular water compartment * C. Gastric juice contains HCl, pepsins, and mucus * D. Intrinsic factor is produced by oxyntic cells in the duodenum * E. Nonwater miscibility is a feature of essential amino acids

Answer 67

C

Question 68

Which statement below is incorrect? * A. The coiling/folding of one chain and the interaction of 2 or more peptide chain are the primary and quaternary structures of proteins, respectively. * B. All polypeptide chains have a primary structure * C. None of these statements are incorrect * D. BCAAs contain nonpolar/hydrophobic side chains * E. Polarity of an amino acid depends on its ability to interact with water and electrolytes

Answer 68

A

Question 69

Which below are symptoms of hypothyroidism in an infant? * A. Stunt growth * B. Impaired fat and carbohydrate metabolism * C. Impaired body temperature regulation * D. All options are correct * E. Cretinism and impaired protein synthesis

Answer 69

D

Question 70

How does LDL donate its cholesterol content to peripheral tissues? * A. By turning into IDL and interacting with HDL in the circulation * B. By receiving apoE from HDL and undergoing endocytosis in hepatocytes * C. By exchanging lipids with HDL upon binding to the LDL receptor * D. By undergoing endocytosis after interacting with the LDL receptor * E. By interacting with PCSK9 in the circulation

Answer 70

D

Question 71

Which statement below is correct? * A. Hydrogenation of unsaturated fatty acids causes rancidity in oils * B. 22:6 delta 4,7,10,13,16,19 is an omega 3 fatty acid * C. Lack of linoleic and linolenic fatty acids can lead to retarded growth in humans * D. Bacteria in the colon ferment soluble fibers and produce long chain fatty acids * E. The portal vein carries nutrients and insulin towards the pancreas

Answer 71

C

Question 72

What is the function of LPL in the capillaries of the adipose tissue? * A. The hydrolyze triacylglycerols in chylomicrons and VLDL * B. To facilitate the formation of glycerol from glycolysis * C. The hydrolyze triacylglycerols in LDL particles * D. To esterify fatty acids in chylomicrons * E. To transfer cholesterol esters from HDL to VLDL

Answer 72

A

Question 73

What is the main fate of bile acids in the gut? * A. Degradation by the liver * B. Conversion into free cholesterol by gut bacteria * C. Excretion in the feces * D. Reabsorption in the terminal part of the ileum * E. Degradation by colonic bacteria

Answer 73

D

Question 74

What are chylomicrons composed of when they enter the lactal? * A. Triglycerides, phospolipids, cholesterol, and apoB48 * B. 2MAGs, cholesterol, and apoB48 * C. Phospholipids, 1MAGs, and cholesterol * D. Cholesterol, phospholipids and apoC2 * E. Cholesterol, phospholipids and apoB48

Answer 74

A

Question 75

What effects are attributed to the intake of the n-3 fatty acids Eicosapentenoic (EPA) and docosahexaenoic (DHA) in the body? * A. Enhanced inflammation * B. Increased production of short chain fatty acids by the gut bacteria * C. Attenuation of inflammation * D. Increased oxidation of fatty acids by the liver * E. Enhanced iron absorption

Answer 75

C

Question 76

Which statement below is correct? * A. HDL becomes spherical after interacting with non hepatic tissues * B. LCAT converts cholesterol into cholesterol esters within HDL particles * C. All options are correct * D. Nascent HDLs are small and discoidal particles * E. HDL particles pick up cholesterol from other lipoproteins and peripheral tissues

Answer 76

C

Question 77

Which statement below is incorrect? * A. In the eye, trans-retinal is transiently dissociated from opsin * B. Triacylglycerols are mostly hydrolyzed in the duodenum and reassembled in enterocytes * C. Fat-soluble vitamins from foods leave enterocytes via the portal vein * D. Visceral adipose tissue provides cushioning for internal organs * E. Cholesterol and phospholipids are found in cell membranes

Answer 77

C