Macromolecules #2: Lipids

Question 1

Fat is what at room temperature?

Answer 1

Solid

Question 2

Oil is what at room temperature

Answer 2

Liquid

Question 3

Lipids contribute to 30% to 50% of what?

Answer 3

Calories and of physical weight/mass of diet.

Question 4

Lipids are soluble in what? What are they not soluble in?-Because of what?

Answer 4

Organic solvents; Water-because they are all hydrophobic.

Question 5

Lipids are primarily consumed for what?

Answer 5

Energy (specifically dietary lipids are primarily used/stored for energy.

Question 6

What is a big part of lipids used for?

Answer 6

Insulation

Question 7

Lipids are diverse groups, which means what?

Answer 7

There is no basic sub-unit

Question 8

What elements do lipids contain?

Answer 8

Carbon, hydrogen, and oxygen but the H:O is not in a 2:1 ratio.

Question 9

Lipids don’t come in what? What do lipids not have?

Answer 9

A specific ratio; there is no specific structural formula for lipids.

Question 10

What are the 4 major sub-groups of lipids?

Answer 10

-Glycerides (Fats): Include triglycerides
-Phospholipids: Main component of cell membranes.
- Steroids
- Waxes

Question 11

What differentiates a phospholipid from a triglyceride?

Answer 11

-Phospholipid: Two fatty acid chains.
-Triglyceride: Three fatty acid chains

Question 12

What does cholesterol have that phospholipids and triglycerides don’t?

Answer 12

-Four hydrocarbon rings
- One hydrocarbon tail

Question 13

What is one function of Triglycerides?

Answer 13

Long term energy storage, which is 2x energy that comes from carbohydrates.

Question 14

How many times (numerically) of energy can lipids provide vs carbs? Why is that?

Answer 14

-2x to 3x of energy that carbs can give.
-Because lipids are massive - because of that lipids take time to break down - because of that lipids don’t provide energy immediately like carbs.

Question 15

What is another reason why lipids don’t provide energy immediately?

Answer 15

Lipids do not always make themselves accessible to enzymes.

Question 16

What are lipids the main source of? It is used as and is for?

Answer 16

-Potential Energy
-Used as needed and is for more long-term energy.

Question 17

During sleep, humans burn what? Why?

Answer 17

-Lipids
-Bc of no rush for time + no need for any other short-term energy requirements.

Question 18

Lipids take a lot of what to be broken?

Answer 18

Energy

Question 19

What does lipids taking a lot of energy to be broken result in?

Answer 19

Only breaking down lipids when the need is necessary.

Question 20

What is a 2nd function of triglycerides?

Answer 20

Cushions/protects organs (e.g. kidney, reproductive organs, etc…)

Question 21

What does each organ have?

Answer 21

A layer of lipids (fats) to cushion/protect it.

Question 22

What is a 3rd function of triglycerides?

Answer 22

Insulation: Helps maintain constant internal temperature

Question 23

Why are triglycerides important for insulation?

Answer 23

Because humans cannot regulate internal body temperature; without them, we would not be able to regulate it otherwise.

Question 24

Why would we use lipids for insulation rather than carbs?

Answer 24

Because carbs are much easier for enzymes to find than lipids-therefore, they do not last as long.

Question 25

What is a more immediate purpose for triglycerides?

Answer 25

Insulation