Metabolism/Nutrition/Energy Balance

Question 1

What are macromolecules?

Name the 4 most important

Answer 1

Large molecules

Carbohydrates
Lipids
Proteins
Nucleic Acid

Question 2

What the functions of Proteins? (6)

Answer 2

Enzymes
Antibodies
Hormones
Structure
Contraction
Transport

Question 3

What are the functions of carbohydrates?

Answer 3

Energy Source

Question 4

What are the functions of lipids?

Answer 4

Energy
Membrane components
Hormones

Question 5

What is the function of nucleic acid?

Answer 5

Information storage and transmission via DNA and RNA.

Question 6

How are carbohydrates classified?

Which are considered complex and why?

Answer 6

Monosaccharides
Disaccharides
Oligosaccharides
Polysaccharides (>10 mononumeric units)

Polysaccharides as they need to be broken down before they can be absorbed.

Question 7

What are the 4 main types of lipids?

Answer 7

Fatty Acids
Triglycerides (Triacylglycerides)
Cholesterol
Cholesterol esters.

Question 8

How can lipids be modified?

Answer 8

Phospholipids: Addition of phosphate to a fatty acid chain via glycerol or sphingosine.

Glycolipids: Carbohydrate saccharide attatches to a fatty acid chain directly or via glycerol or sphingosine.

Question 9

What are the two modified lipids and why are they important?

Answer 9

Phospholipids
Glycolipids

Both are important components of cell membranes, especially phospholipids (bi-layer)

Glycolipids act as cell surface recognition molecules.

Question 10

What are ketone bodies why are they formed and what is their clinical relevance?

Answer 10

Acetoacetic acid + B-hydroxybutyric acid.

Small fatty acids formed by oxidation of fatty acids in the liver.

They are formed during fasting and act to protect the brain.

Type 1 diabetics can have an excessive formation of ketone bodies during hypoglycaemia causing ketoacidosis.

Question 11

What clinical condition occurs due to a build of ketone bodies?

Who is most susceptible to this and what is a test for early onset?

Answer 11

Ketoacidosis

Type 1 diabetes during hypoglycaemia

Acetone is formed as bi-product of ketone body metabolism and is exhaled.

Question 12

What are the main sources of energy? (4)

Answer 12

Glucose
Fatty Acids
Ketones
Amino Acids

Question 13

How are triglycerides stored?

Which storage system is considered most harmful in large amounts?

Answer 13

In white adipose tissue (internal, visceral or subcutaneous?)

Visceral

Question 14

How can glucose be stored?

Answer 14

Triglyceride

Glycogen

Question 15

How is glucose stored and where?

Answer 15

Glycogen in the liver and skeletal muscle

Triglycerides

Question 16

Can fatty acids be converted to glucose?

Can glucose be converted to fatty acid?

Answer 16

No

Yes

Question 17

What are the names of the major glucose transporters and what method of transport to they use?

Which are sensitive to insulin?

Answer 17

GLUT 1-5 Passive transport

SGLT 1 & 2 Active transport.

GLUT-1,3&4

Question 18

What is the energy carrying molecule?

How does it release and store energy?

Answer 18

Adenosine Triphosphate (ATP)

Energy from oxidation of nutrient is stored in high-energy bonds when a phosphate group is added to ADP. (catabolism)

The energy stored in the high energy bond of the phosphate group is released when needed (anabolism).