21. Lipid Structure

11) Match structure below with correct structural formulas from the drop-down menu:

1. CH3(CH2)6CH=CH(CH2)2COOH The correct structure includes an omega carbon with 3 hydrogens on the left followed by six CH2 groups, a CH, a double bond, another CH, two CH2 groups, and a carboxylate group on the right.

5) Fatty acids normally contain anywhere from 4-36 carbon atoms. Depending on the length they are given different names and exhibit different characteristics. Short chain saturated fatty acids are (check all that apply):

4 to 7 carbons long Liquid at room temperature Short chain saturated fatty acids have 4-7 carbons and are liquids at room temperature.

8) Match structure below with correct structural formulas from the drop-down menu:

5.CH3(CH2)7CH=CH(CH2)5COOH omega carbon with 3 hydrogens on the left followed by seven CH2 groups, a CH, a double bond, another CH, one CH2 group, and a carboxylate group on the right.

20) Select all of the following that are TRUE:

A is the bond broken during beta oxidation. C makes this an omega 3 fatty acid

2) Identify lipid molecules shown below in the following order: 1- Medium Chain Saturated Fatty Acid; 2- Long Chain Saturated Fatty Acid; 3- Omega 3 Fatty Acid; 4- Long Chain Unsaturated Fatty Acid; 5- Arachiodonic Acid; 6- Cholesterol; 7- Triglyceride)

A-G-F-D-B-C-E A=Medium Chain Saturated Fatty Acid; G=Long Chain Saturated Fatty Acid; F= Omega 3 Fatty Acid; D= Long Chain Unsaturated Fatty Acid; B=Arachiodonic Acid; C=Cholesterol; E=Triglyceride

1) Identify labeled parts of the following lipid molecule:

A-Phosphate group; B-unsaturated fatty acid; C-saturated fatty acid

3) For the image below, which option correctly identifies the part of the fatty acid indicated by C?

Beta carbon : A- omega carbon, B- alpha carbon, D- beta bond.

12) For the image below, which option correctly identifies the part of the fatty acid indicated by C?

Beta carbon C is pointing to the beta carbon. A- omega carbon, B- alpha carbon, D- beta bond.

2) Match structure below with correct structural formula:

CH3(CH2)7CH=CH(CH2)5COOH

4) Which of the following fatty acids is polyunsaturated?

D

14) Which of the following is an essential fatty acid?

D Essential fatty acids are unsaturated fatty acids and have an omega 3 and/or and omega 6 double bond.

26) Fatty acids with only double bonds between carbon atoms in the hydrocarbon chain are called saturated fatty acids.

False Saturated fatty acids do not have double bonds between the carbons in the hydrocarbon chain. Unsaturated fatty acids have one or more double bonds between the carbons within the hydrocarbon chain.

19) If the fatty acid in the red box is replaced with the following fatty acid: CH3(CH2)18COOH, what will be a likely result?

Membrane fluidity will decrease Replacing an unsaturated fatty acid tail with a saturated fatty acid tail within a phospholipid molecule will result in decreased fluidity because saturated fatty acids stack better together and make the molecule more stable. Which means a more solid state is favored, not a liquid (fluid) state.

25) Monounsaturated fatty acids have only one double bond

True

7) Long chain unsaturated fatty acids are (check all that apply):

more than 12 carbons long Liquid at room temperature

6) Medium chain saturated fatty acids are (check all that apply):

8 to 12 carbons long liquid at room temperature

1) Identify the different parts of the fatty acid molecule below: alpha carbon, alpha bond, beta carbon, beta bond, omega carbon and omega bond:

A- omega carbon, B- double bond, C- beta carbon, D- beta bond, E- alpha carbon and F- alpha bond

3) Identify labeled parts of the following lipid molecule:

A-Phosphate group; B-unsaturated fatty acid; C-saturated fatty acid A=phosphate group. It contains a phosphorus atom surrounded by four oxygens. B= unsaturated fatty acid. It is a fatty acid with one or more double bonds within the hydrocarbon chain. C=saturated fatty acid. It is a fatty acid that doesn't not contain double bonds between the carbons within the hydrocarbon chain.

15) Which of the formulae below describes a saturated fatty acid?

C16H32O2 Saturated fatty acids have the most possible hydrogens surrounding the carbons within the hydrocarbon chain. You can identify saturated fatty acids by comparing the number of carbons to the number of hydrogens. There should be twice as many hydrogens as carbons. In addition, two oxygen atoms are present. These oxygen atoms make up part of the carboxylate group.

18) Which of the following is an example of an essential fatty acid? (check all that apply)

CH3CH2CH=CH(CH2)4COOH CH3CH2CH=CHCH2CH=CH(CH2)4COOH CH3(CH2)4CH=CH(CH2)6COOH Essential fatty acids contain an omega 3 and/or omega 6 double bond(s) within the carbons in the hydrocarbon chain.

21) The acid portion of a fatty acid corresponds to which one of the following groups/molecules?

COOH

9) The acid portion of a fatty acid corresponds to which one of the following groups/molecules?

COOH

5) Which of the following is an essential fatty acid? Captionless Image

D Essential fatty acids are unsaturated fatty acids and have an omega 3 and/or and omega 6 double bond.

13) Which of the following fatty acids is polyunsaturated?

D This structure is not polyunsaturated. "Poly" means many and it is referring to having two or more double bonds between the carbons in the hydrocarbon chain.

Learning Objective

Given a model, the student identifies the important aspects of chemical structure of saturated, unsaturated fats, and polyunsaturated fats. (4 questions on the assessment)

10) Saturated fatty acids have more _________________ than unsaturated fatty acids of the same length.

Hydrogen atoms Saturated fatty acids do not have double bonds between the carbons within the hydrocarbon chain. Fatty acids have the same amount of oxygen atoms, two. These oxygen atoms are found within the carboxylate group. Both saturated and unsaturated fatty acids can have up to 24 carbons.

22) Saturated fatty acids have more _________________ than unsaturated fatty acids of the same length.

Hydrogen atoms Saturated fatty acids do not have double bonds between the carbons within the hydrocarbon chain. Fatty acids have the same amount of oxygen atoms, two. These oxygen atoms are found within the carboxylate group. Both saturated and unsaturated fatty acids can have up to 24 carbons.

8) If the fatty acid in the red box is replaced with the following fatty acid: CH3(CH2)18COOH, what will be a likely result?

Membrane fluidity will decrease membrane fluidity will decrease. Replacing an unsaturated fatty acid tail with a saturated fatty acid tail within a phospholipid molecule will result in decreased fluidity because saturated fatty acids stack better together and make the molecule more stable. Which means a more solid state is favored, not a liquid (fluid) state.

16) For the image below, which option correctly identifies the part of the fatty acid indicated by A?

Omega carbon A is the omega carbon B- alpha carbon, C- beta carbon, D- beta bond.

6) For the image below, which option correctly identifies the part of the fatty acid indicated by A?

Omega carbon B- alpha carbon, C- beta carbon, D- beta bond.

27) What type of essential fatty acid does the following structure represent:

Omega-6 this structure has an omega-6 double bond, not an omega-3 or omega-9 double bond. It is not a saturated fatty acid because it has a double bond within the hydrocarbon chain.

23) How many hydrogens can be accommodated by each of the carbons participating in the double bond: -C-C=C-C-

One carbons around the double bond can hold one hydrogen atom each. Carbon can be surrounded by four bonds. Adding one hydrogen to each carbon satisfies this criteria.

4) What are the differences between the saturated and unsaturated fatty acids in structure?

Saturated Pack tightly-solid at room temperature No double bonds Abundant in animal fats (for example: butter) Unsaturated Abundant in vegetable oil At least one double bond Do not pack tightly-liquid at room temperature

7) CH3(CH2)4CH=CH(CH2)6COOH is an example of which type of fatty acid?

Unsaturated fatty acid The structure represents a fatty acids with an omega 6 double bond between the carbons in the hydrocarbon chain. Unsaturated fatty acids have at least one double bond between the carbons in the hydrocarbon chain. It is not a saturated fatty acid because saturated fatty acids do not have any double bonds between the carbons in the hydrocarbon chain. It is not cholesterol because cholesterol has a tetracyclic (tetra means four) ring structure.

17)CH3(CH2)4CH=CH(CH2)6COOH is an example of which type of fatty acid? (check all that apply)

Unsaturated fatty acid Omega-6 fatty acid Unsaturated fatty acids have at least one double bond between the carbons in the hydrocarbon chain. The correct structure is not a polyunsaturated fatty acid, but a monounsaturated fatty acid because it has only one double bond in the hydrocarbon chain. Polyunsaturated fatty acids have two or more double bonds within the hydrocarbon chain. Saturated fatty acids do not have any double bonds between the carbons in the hydrocarbon chain. Cholesterol has a tetracyclic (tetra means 4) ring structure.

9) Match structure below with correct structural formulas from the drop-down menu:

2.CH3(CH2)4CH=CH(CH2)3COOH omega carbon with 3 hydrogens on the left followed by four CH2 groups, a CH, a double bond, another CH, three CH2 groups, and a carboxylate group on the right.

10) Match structure below with correct structural formulas from the drop-down menu:

4.CH3(CH2)3CH=CH(CH2)4COOH The correct structure includes an omega carbon with 3 hydrogens on the left followed by three CH2 groups, a CH, a double bond, another CH, four CH2 groups, and a carboxylate group on the right.

24) Hydrogens of the carbon=carbon double bond with trans orientation (in an unsaturated fatty acid) are placed on the same side.

False trans" means across. The hydrogen atoms around the double bond within a trans unsaturated fatty acid are across from each other, not on the same side.