Lipids Worksheet with questions and diagrams for learning about lipid structure and properties.
A worksheet titled "Lipids Worksheet" with questions about lipids, including their organic nature, elemental composition, formation, saturation, examples in diet, and waterproof properties, featuring diagrams of lipid molecules.
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Step-by-step solution for: Solved Name: Pd: 1. Are lipids organic molecules? Lipids | Chegg.com
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Show Answer Key & Explanations
Step-by-step solution for: Solved Name: Pd: 1. Are lipids organic molecules? Lipids | Chegg.com
Let's go through each question on the Lipids Worksheet and provide clear, accurate answers with explanations.
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Answer:
Yes, lipids are organic molecules.
Why? Because they are composed primarily of carbon (C), hydrogen (H), and oxygen (O) — the main elements found in organic compounds. They are also derived from living organisms and contain carbon-carbon bonds, which is a hallmark of organic chemistry.
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1. Carbon (C)
2. Hydrogen (H)
3. Oxygen (O)
*(Some lipids may also contain phosphorus (P), especially in phospholipids.)*
---
a. Fatty acids to glycerol → ✔ This describes triglycerides, the most common type of lipid.
b. Hydroxyl groups to glycerol → ✘ Not correct; hydroxyl groups are part of glycerol but not what forms lipids.
c. Cholesterol to a carbonyl group → ✘ Cholesterol is a steroid, not typically attached to a carbonyl group to form major lipids.
d. Fatty acids to a carbonyl group → ✘ Fatty acids are attached via ester bonds to glycerol, not directly to carbonyl groups.
✔ Correct answer: a. Fatty acids to glycerol
---
We need to examine the structures:
- First molecule: All carbon atoms are connected by single bonds. No double bonds.
→ Saturated
- Second molecule: Contains at least one double bond between carbon atoms (look for C=C).
→ Unsaturated
> So:
> - Left structure: Saturated
> - Right structure: Unsaturated
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Answer: Double bond
Explanation: The presence of a double bond between carbon atoms means fewer hydrogen atoms are bonded, making it "unsaturated."
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Structure shown:
```
H H H H H H H H H H
| | | | | | | | | |
H-C-C-C-C-C-C-C-C-C-C-H
| | | | | | | | | |
H H H H H H H H H H
```
Wait — actually, looking closely, there’s a double bond indicated between two carbons (likely the middle ones). The structure has a C=C bond.
So:
- The long chain with one double bond → Unsaturated fatty acid
- The carbonyl group (C=O) at the end → Carboxyl group
- The rest is the hydrocarbon tail
Labeling:
- Left side (head): Carboxyl group (–COOH)
- Right side (tail): Hydrocarbon chain
- Middle: Double bond (indicates unsaturation)
✔ This is an UNSATURATED lipid (due to the double bond).
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a. Bread → ✘ Mostly carbohydrates
b. Meat → ✔ Yes, meat contains fats (lipids)
c. Oils/Fats/Waxes → ✔ These are lipids themselves
d. Chocolate → ✔ Contains cocoa butter (a lipid)
✔ Correct answers: b, c, d
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Answer: Olive oil, avocado, nuts, salmon (contains omega-3 fatty acids)
Example: Olive oil – rich in monounsaturated fats.
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Answer: Butter, cheese, red meat, coconut oil
Example: Butter – high in saturated fatty acids.
---
Answer:
Lipids are hydrophobic (repel water) because they are nonpolar molecules. Water is polar and forms hydrogen bonds, but lipids have no charged or polar groups to interact with water. Their long hydrocarbon chains do not dissolve in water, so they repel it.
Thus, lipids are “waterproof” because they do not mix with or dissolve in water.
---
Answer:
A bird's feathers are coated with oils (lipids) secreted by the preen gland. This coating makes the feathers water-resistant, helping birds stay dry when swimming or flying in rain.
Another example: Waxy coating on leaves prevents water loss and keeps them dry.
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1. Yes, lipids are organic molecules because they contain carbon and are derived from living organisms.
2. Elements: Carbon, Hydrogen, Oxygen
3. a. Fatty acids to glycerol
4. First: Saturated, Second: Unsaturated
5. Double bond
6. Labels:
- Left: Carboxyl group
- Middle: Double bond
- Right: Hydrocarbon tail
→ Unsaturated lipid
7. b. Meat, c. Oils/Fats/Waxes, d. Chocolate
8. Example: Olive oil
9. Example: Butter
10. Lipids are nonpolar and cannot form hydrogen bonds with water → hydrophobic
11. Bird feathers coated with oil resist water (or waxy plant leaves)
Let me know if you'd like this formatted as a printable worksheet!
---
1. Are lipids organic molecules? Why or why not?
Answer:
Yes, lipids are organic molecules.
Why? Because they are composed primarily of carbon (C), hydrogen (H), and oxygen (O) — the main elements found in organic compounds. They are also derived from living organisms and contain carbon-carbon bonds, which is a hallmark of organic chemistry.
---
2. What elements do lipids contain?
1. Carbon (C)
2. Hydrogen (H)
3. Oxygen (O)
*(Some lipids may also contain phosphorus (P), especially in phospholipids.)*
---
3. Many lipids are formed by the attachment of three:
a. Fatty acids to glycerol → ✔ This describes triglycerides, the most common type of lipid.
b. Hydroxyl groups to glycerol → ✘ Not correct; hydroxyl groups are part of glycerol but not what forms lipids.
c. Cholesterol to a carbonyl group → ✘ Cholesterol is a steroid, not typically attached to a carbonyl group to form major lipids.
d. Fatty acids to a carbonyl group → ✘ Fatty acids are attached via ester bonds to glycerol, not directly to carbonyl groups.
✔ Correct answer: a. Fatty acids to glycerol
---
4. Label the below lipids as either saturated or unsaturated.
We need to examine the structures:
- First molecule: All carbon atoms are connected by single bonds. No double bonds.
→ Saturated
- Second molecule: Contains at least one double bond between carbon atoms (look for C=C).
→ Unsaturated
> So:
> - Left structure: Saturated
> - Right structure: Unsaturated
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5. If a lipid molecule contains at least one ________, it is unsaturated.
Answer: Double bond
Explanation: The presence of a double bond between carbon atoms means fewer hydrogen atoms are bonded, making it "unsaturated."
---
6. Label the parts of the below lipid molecule. Is this a saturated or unsaturated lipid?
Structure shown:
```
H H H H H H H H H H
| | | | | | | | | |
H-C-C-C-C-C-C-C-C-C-C-H
| | | | | | | | | |
H H H H H H H H H H
```
Wait — actually, looking closely, there’s a double bond indicated between two carbons (likely the middle ones). The structure has a C=C bond.
So:
- The long chain with one double bond → Unsaturated fatty acid
- The carbonyl group (C=O) at the end → Carboxyl group
- The rest is the hydrocarbon tail
Labeling:
- Left side (head): Carboxyl group (–COOH)
- Right side (tail): Hydrocarbon chain
- Middle: Double bond (indicates unsaturation)
✔ This is an UNSATURATED lipid (due to the double bond).
---
7. Lipids are found in:
a. Bread → ✘ Mostly carbohydrates
b. Meat → ✔ Yes, meat contains fats (lipids)
c. Oils/Fats/Waxes → ✔ These are lipids themselves
d. Chocolate → ✔ Contains cocoa butter (a lipid)
✔ Correct answers: b, c, d
---
8. Give an example of an UNSATURATED lipid in your diet:
Answer: Olive oil, avocado, nuts, salmon (contains omega-3 fatty acids)
Example: Olive oil – rich in monounsaturated fats.
---
9. Give an example of a SATURATED lipid in your diet:
Answer: Butter, cheese, red meat, coconut oil
Example: Butter – high in saturated fatty acids.
---
10. Why are lipids "waterproof"?
Answer:
Lipids are hydrophobic (repel water) because they are nonpolar molecules. Water is polar and forms hydrogen bonds, but lipids have no charged or polar groups to interact with water. Their long hydrocarbon chains do not dissolve in water, so they repel it.
Thus, lipids are “waterproof” because they do not mix with or dissolve in water.
---
11. Give an example that illustrates lipids being waterproof:
Answer:
A bird's feathers are coated with oils (lipids) secreted by the preen gland. This coating makes the feathers water-resistant, helping birds stay dry when swimming or flying in rain.
Another example: Waxy coating on leaves prevents water loss and keeps them dry.
---
✔ Final Answers Summary:
1. Yes, lipids are organic molecules because they contain carbon and are derived from living organisms.
2. Elements: Carbon, Hydrogen, Oxygen
3. a. Fatty acids to glycerol
4. First: Saturated, Second: Unsaturated
5. Double bond
6. Labels:
- Left: Carboxyl group
- Middle: Double bond
- Right: Hydrocarbon tail
→ Unsaturated lipid
7. b. Meat, c. Oils/Fats/Waxes, d. Chocolate
8. Example: Olive oil
9. Example: Butter
10. Lipids are nonpolar and cannot form hydrogen bonds with water → hydrophobic
11. Bird feathers coated with oil resist water (or waxy plant leaves)
Let me know if you'd like this formatted as a printable worksheet!
Parent Tip: Review the logic above to help your child master the concept of lipids worksheet.
