B1.1 Carbohydrates and lipids

Question 1

The simplest form of carbohydrates, consisting of single sugar units

like glucose and fructose

Answer 1

Monosaccharides

These are the basic building blocks for more complex carbohydrates

Question 2

What is the primary function of lipids in the human body?

Answer 2

Long-term energy storage and insulation in the human body.

They are also key components of cell membranes

Question 3

True or False: Saturated fats are typically liquid at room temperature.

Answer 3

False

Saturated fats are usually solid at room temperature due to their straight molecular structure, which allows them to pack tightly.

Question 4

The process of forming a triglyceride

Answer 4

Triglyceride forms by a condensation reaction between one glycerol molecule and three fatty acid molecules.

This process results in the release of water molecules

Question 5

Type of bond formed between amino acids in a protein

Answer 5

Peptide bond

This bond is crucial for the protein’s structure and function

Question 6

What is the role of phospholipids in cells?

Answer 6

Phospholipids form the primary structure of cell membranes

Their hydrophilic and hydrophobic ends make them ideal for creating the cell membrane’s bilayer

Question 7

The basic structure of a carbohydrate molecule

Answer 7

Carbon, hydrogen, and oxygen atoms, typically in a 1:2:1 ratio.

This basic formula is Cn(H2O)n

Question 8

True or False: Lipids are polar molecules

Answer 8

False

Lipids are non-polar, making them hydrophobic (water-repelling)

Question 9

What distinguishes a saturated fatty acid from an unsaturated one?

Answer 9

Saturated fatty acids have no double bonds in their hydrocarbon chain, whereas unsaturated fatty acids do

This affects their physical state at room temperature - saturated fats are usually solid, and unsaturated fats are typically liquid

Question 10

How do carbohydrates serve in cellular respiration?

Answer 10

Carbohydrates are broken down to glucose, which is used in cellular respiration to produce ATP, the cell’s energy currency

This process is vital for providing energy to cells

Question 11

It is a polysaccharide that serves as a form of energy storage in animals

Answer 11

Glycogen

Question 12

Where is glycogen stored in the body?

Answer 12

In the liver and muscles

Question 13

Describe the ‘hydrophobic effect’ in relation to lipids.

Answer 13

The tendency of non-polar lipid molecules to aggregate in water to minimize their exposure to water molecules.

This effect is critical in forming cell membranes and lipid bilayers.

Question 14

Long chains of monosaccharides linked by glycosidic bonds. Example: Starch

Answer 14

Polysaccharides

They serve various functions, including energy storage and structural support.

Question 15

Fill in the blank: _______ are the simplest lipids, formed from glycerol and fatty acids.

Answer 15

Triglycerides

They are the main form of stored energy in animals

Question 16

What is the significance of cholesterol in the body?

Answer 16

Cholesterol is essential for the synthesis of cell membranes, hormones, and vitamin D

It’s transported in the blood by lipoproteins

Question 17

The structure of a phospholipid molecule

Answer 17

It has a hydrophilic head containing a phosphate group and two hydrophobic fatty acid tails

This dual nature is crucial for forming cell membranes

Question 18

True or False: Glycogen is a type of lipid

Answer 18

False

Glycogen is a polysaccharide, a complex carbohydrate

Question 19

What is the difference between alpha and beta glucose?

Answer 19

The difference lies in the position of the -OH group on the first carbon: alpha glucose has it below the ring plane, beta glucose above.

This affects how they form polysaccharides like starch and cellulose

Question 20

How do unsaturated fats affect cholesterol levels?

Answer 20

Unsaturated fats can help lower LDL (bad) cholesterol levels while maintaining or increasing HDL (good) cholesterol levels.

This makes them a healthier choice compared to saturated fats

Question 21

What is the primary function of carbohydrates in living organisms?

Answer 21

Source of energy and as structural components in cells

They are key in energy metabolism and cell structure

Question 22

Describe the significance of the lipid bilayer in cell membranes

Answer 22

The lipid bilayer forms a barrier that controls the entry and exit of substances in and out of the cell

Its fluid nature allows for cell flexibility and transport

Question 23

Fill in the blank: Cellulose is a _________ made of beta-glucose units

Answer 23

Polysaccharide

It’s a major component of plant cell walls, providing structural support

Question 24

How do trans fats affect human health?

Answer 24

They increase the risk of heart disease by raising LDL (bad) cholesterol and lowering HDL (good) cholesterol

They are commonly found in processed foods

Question 25

Identify the bond type that connects monosaccharides in disaccharides

Answer 25

Glycosidic bond

This bond forms through a dehydration reaction between two sugar molecules