Lipids (fats)

Question 1

What are dominant features of a lipid

Answer 1

Hydrogen and carbon

Question 2

What are lipids

Answer 2

Iipids (fats) are molecules made up mainly of carbon and hydrogen and are said to be insoluble in water (due to the non-polarity of the chain). They travel around the blood bound yo specific proteins called lipoproteins

Question 3

How do lipids travel

Answer 3

They travel around the blood, bound to specific proteins called lipoproteins

Question 4

List examples of lipids

Answer 4

Fatty acids, triglycerol, phospholipids and cholesterol

Question 5

What is the main storage molecules of the body

Answer 5

Fats, we store excess energy in the form of lipids (mainly triglycerides)

Question 6

What are the four functions of lipids in the body

Answer 6

1. Storage of energy (eg. Adipose tissue insulates against body temo changes)
2. source of energy - twice the energy/gram than protein and carbohydrates (1 gram produced 9 calories of energy)
3. basic component of cell membrane
4. chemical messengers - steroid hormones

Question 7

What are the two types of lipids

Answer 7

1. Lipids with fatty acids included

2. Lipids with fatty acids not included

Question 8

Examples of lipids with fatty acids

Answer 8

truglycerides and phospholipids

Question 9

Fatty acid included structures

Answer 9

• 8-18 hydrocarbon chain
• Long hydrocarbon chain with a carboxyl group attached to the end
• insoluble in water
• Can either be saturated or unsaturated

Question 10

characteristics of saturated fatty acids

Answer 10

• only single bonds
• maximum hydrogens present
• Single bonds means they have no kinks but have a linear structure. This means they can be easily stacked and tightly. Increasing the MP and BP.
• solid at room temo
  Eg. Butter and stearic acid (found in steak with 18 carbon atoms)

Question 11

characteristics of unsaturated fatty acids

Answer 11

• one or more double kinks
• can either be cis or trans (mostly cis)
• causes a kink and makes it harder to tightly stack
• lower MP and BP
• liquid at room temperature
• Eg. Margarine
  Oleic acid (has 18 carbon atoms)

Question 12

Cis isomer

Answer 12

Hydrogen atoms on same side producing a kink. more than 99% of fats exist in this cis transformation

Question 13

Trans isomer

Answer 13

hydrogen atoms on opposite sides - more linear structure

Question 14

Trans fats:

Answer 14

Found in processed foods. They are formed by hydrogenation of cis isomers (bombarding cis fats with hydrogens). They have a higher MP and BP and can lead to many cardiovascular diseases.

Question 15

What are natural fats and oils

Answer 15

They are mixtures made up of both saturated and unsaturated fatty acids.
Eg. Olive oil has 84% of unsaturated and 16% of saturated fatty acids

Question 16

What are essential diietry fats

Answer 16

Fats that our bodies do not produce naturally and rely on our consumption of certain foods. 
Eg. Omega 3 (alpha linoleic - 18 carbons and 3 double bonds) 
Omega 6 (linoleic - 18 carbonds and 2 double bonds)

Question 17

What are two examples of fatty acids

Answer 17

triglycerides and phospholipids

Question 18

What is triglyceride

Answer 18

It is an example of a fatty acids. It is the main lipid storage in the body. These lipids are stored in the adipose tissues. They are composed of a glycerol and three fatty acids

Question 19

What are phospholipids

Answer 19

Another example of a fatty acid containing structure. It is also known as glycerophospholipids. It is the most abundant molecule in the plasma cell membrane.. Made up of a glycerol, 2 fatty acids, a phosphate group and a polar molecule

Question 20

Why can’t a membrane be made in a single layer of the phospholipids?

Answer 20

Because they are made up of both a hydrophobic and hydrophilic end, causing them to fold in on themselves, creating a micelle.

Question 21

What is the name of lipids that do not contain fatty acids called?

Answer 21

Steroids. Including cholesterol, sex hormones and other hormones.

Question 22

What is a steroid?

Answer 22

A steroid molecule consists of a characteristic 4 ring hydrocarbon structure.

Question 23

What is the most abundant steroid lipid in the body

Answer 23

Cholesterol

Question 24

Where is cholesterol synthesised

Answer 24

liver

Question 25

Where is cholesterol consumed from

Answer 25

meats, milk and eggs

Question 26

What is a gallstone ?

Answer 26

Harden cholesterol stones, caused by the imbalance of bile (helps in digestion of fats). This bile is made by the liver and passed to the gallbladder through a series of tunnels called bile ducts. Over time it becomes more concentrated, helping break down fats faster

Question 27

What is another type of lipids in the body

Answer 27

Sex hormones

Question 28

What is testosterone

Answer 28

They are the sex hormones in males which are responsible for the development of male organs and male sexual characteristics including muscles, facial hair and sperm formation

Question 29

What is Estradiol?

Answer 29

They are the sex hormones for women. They are responsible for the development of sexual characteristics and ovulation

Question 30

What is Progesterone?

Answer 30

The sex hormones used to prepare for fertilize egg

Question 31

What are anabolic steroids

Answer 31

Synthetic steroids. Synthetic derivatives of testosterone. They have a similar structure but build muscle mass faster and to a greater extent. They are used illegally to build muscle mass but have side effects including infertility, growth effects (short stature), fluid retention, gynecomastia, and liver damage

Question 32

What are some lipids that do not contain fatty acids

Answer 32

Cholesterol, sex hormones and other hormones

Question 33

What is Glucocorticoids?

Answer 33

A stress hormone that helps relieve stress but can be harmful for the body. They regulate carbohydrates and protein metabolism in the body Eg. Cortisol