Topic 3 - Energy Systems past paper questions

Distinguish between saturated and unsaturated fatty acids

Fatty acids are long chain hydrocarbons containing carboxyl (COOH) at one end.

There are two types of fatty acids, saturated and unsaturated

Saturated fatty acids have no double bond between the individual carbon atoms

Unsaturated fatty acids contain one or more double bonds between the carbon atoms in the fatty acid chain

Depending on the amount of double bonds between the carbon atoms, mono/di/oligo/poly saccahrides can be formed which are classified on the number of monosaccharides that bond together

Mono - one
Di - two
Oligo - 3-9
Poly - 10+

Describe how a glucose molecule forms a polysaccharide molecule

First, a glucose molecule is broken down into glycogen via glycogenesis after the release of insulin from the pancreas

Insulin is a regulatory hormone released by the pancreas to decrease blood glucose levels

Then , when glycogen is made and has been diffused into the liver or the skeletal muscle, it binds with other glycogen molecules to form a double bond between the carbon atoms in the fatty acids.

This therefore, creates a bond between monosaccharides, making disaccharides.

This process then continues to form polysaccharides which have 10+ double bonds between the carbon atoms in the fatty acid chains

Outline the functions of protein

Protein is comprised of CHON (carbon, hydrogen, oxygen and nitrogen in a ratio of 1:1:1:1)

The function of protein is for growth and repair of muscle fires to prevent injury

Describe essential amino acids

Essential amino acids are amino acids that cannot be produced by the body and therefore must be attained from external sources such as food

A main source of essential amino acids is beef

Distinguish between the role of insulin and glucagon in a long distance cycle race (4 marks)

Insulin is a regulatory hormone released from the pancreas to reduce blood glucose levels. Glucagon is also a regulatory hormone released from the pancreas to increase blood glucose levels.

During exercise, there is a decrease in the release of insulin and an increase in the release of glucagon and adrenaline. This causes an increase of glycogenolysis of glycogen, converting it back into glucose and released into the blood from the liver, therefore causing an increase in blood glucose levels to increase energy during exercise.