Biology ib

Question 1

What are the three categories of fatty acids found within lipids?

Answer 1

• Saturated fatty acids
• Monounsaturated fatty acids
• Polyunsaturated fatty acids

Question 2

What defines saturated fatty acids?

Answer 2

Contain single bonds between the carbons, saturated with hydrogens

Question 3

What is the typical state of saturated fatty acids at room temperature?

Answer 3

Solid

Question 4

What are triglycerides that contain only saturated fatty acids called?

Answer 4

Fats

Question 5

What is the melting point of monounsaturated fatty acids compared to saturated fatty acids?

Answer 5

Lower melting point

Question 6

What state are triglycerides containing monounsaturated fatty acids typically in at room temperature?

Answer 6

Liquid (oil)

Question 7

What defines polyunsaturated fatty acids?

Answer 7

Have more than one double bond in the hydrocarbon chain

Question 8

What is the state of triglycerides composed of polyunsaturated fatty acids at room temperature?

Answer 8

Liquid (oil)

Question 9

What two factors affect the melting point of lipids?

Answer 9

• Number of carbons in the fatty acids
• Presence and number of double bonds

Question 10

What is adipose tissue primarily composed of?

Answer 10

Cells that store fat in the form of triglycerides

Question 11

How is the quantity of triglycerides stored in adipose tissue determined?

Answer 11

By the organism’s caloric intake compared to calories burned

Question 12

What happens to triglycerides when sufficient food is not available?

Answer 12

Undergo hydrolysis reactions to provide energy

Question 13

Why are triglycerides useful for long-term energy storage?

Answer 13

Insoluble in body fluids and do not move from storage sites

Question 14

How much energy do triglycerides provide compared to carbohydrates?

Answer 14

Approximately twice as much energy per gram

Question 15

What is the purpose of blubber in animals living in cold regions?

Answer 15

Helps trap heat generated by metabolic activities

Question 16

What is the defining feature of phospholipids?

Answer 16

Amphipathic, containing both hydrophilic and hydrophobic regions

Question 17

What is the structure of a phospholipid?

Answer 17

A polar end with a phosphate group and two long hydrocarbon tails

Question 18

What do phospholipids form in an aqueous solution?

Answer 18

A phospholipid bilayer

Question 19

What is the function of the hydrophobic tails in phospholipid bilayers?

Answer 19

Extend towards each other to avoid aqueous solutions

Question 20

What are steroid hormones derived from?

Answer 20

Lipid cholesterol

Question 21

What are two examples of steroid hormones?

Answer 21

• Oestradiol
• Testosterone

Question 22

How do steroid hormones enter target tissue cells?

Answer 22

Directly through the plasma membrane and nuclear membrane

Question 23

What do steroid hormones direct once inside the nucleus?

Answer 23

The process of transcription

Question 24

What forms of carbohydrates exist?

Answer 24

• Monosaccharides
• Disaccharides
• Polysaccharides

Question 25

What is glucose commonly used for in cells?

Answer 25

As a direct source of cell energy

Question 26

What type of energy storage molecules can glucose form?

Answer 26

* Amylose * Amylopectin * Glycogen

Question 27

What do lipids exist in?

Answer 27

* Triglycerides * Phospholipids * Cholesterol * Steroid hormones

Question 28

What is the solubility of lipids in aqueous solutions?

Answer 28

Low solubility

Question 29

What enables phospholipids to form membrane bilayers?

Answer 29

Amphipathic properties

Question 30

What is a characteristic of carbohydrate polysaccharides like starch and glycogen?

Answer 30

Used for short-term energy storage

Question 31

What type of energy storage do triglycerides provide?

Answer 31

Long-term energy storage

Question 32

What is a soluble product of carbohydrate hydrolysis?

Answer 32

Glucose

Question 33

What is a product of triglyceride hydrolysis?

Answer 33

Fatty acids

Question 34

How do triglycerides compare to carbohydrates in terms of energy storage?

Answer 34

Triglycerides store approximately twice the chemical energy