Exghange Substances (section 3)

Question 1

What is the blood vessel that carries blood to the heart muscle?

Answer 1

Coronary arteries
(Blood vessels on the outside of the heart muscle)

Question 2

What is the cristae in the matrix

Answer 2

Extensions of the inner membrane, which in some species extend across the whole width of the mitochondrion. These provide a large surface area for the attachment of enzymes and other proteins involved in respiration

Question 3

What is the matrix in the mitochondria

Answer 3

Makes up the remainder of the mitochondrion. It contains proteins, lipids, ribosomes and DNA that allows the mitochondrion to control the production of some their own proteins. Many enzymes involved in respiration are found in the matrix

Question 4

Explain the advantages of lipid droplet and Michelle formation

Answer 4

• Droplets increase the Sa
• faster digestion of lipids
• micelles carry fatty acids and glycerol through membrane to intestinal epithelial cells

Question 5

How is the Golgi apparatus involved in the absorption of lipids

Answer 5

It modifies triglycerides and combines them with

Question 6

Describe the relationships between size and surface area to volume ratio of organisms

Answer 6

As size increases, ratio of sa:v decreases

Question 7

What is the role of enzymes in the digestion of proteins (4)

Answer 7

It hydrolyses peptide bonds.
- endopeptidase acts in the middle of the protein
- exopeptidase act at the end of a protein
- dipeptidase acts on a dipeptide/between 2 amino acids

Question 8

Describe the mechanism of breathing that causes air to enter the lungs (3)

Answer 8

• diaphragm muscles contract and diaphragm flattens
• external intercostal muscles contract and private is pull outwards and upwards
• causes the volume increase and pressure decrease in thoracic cavity to below atmospheric pressure. This forces air in