p1 - practice

Question 1

Insects use glucose to generate ATP.
Outline the processes involved in the generation of ATP through chemiosmosis.

Answer 1

• occurs in the mitochondria
• involves the inner membrane and matrix
• involves movement of hydrogen across a membrane
• atp synthase is used
• H ions pumped out of the matrix across membrane and into intermembrane space
• proton gradient created
• atp synthase produces atp from adp + pi
• h ions move from high to low conc

Question 2

Compare and contrast the circulatory systems of mammals and fish

Answer 2

similar -
- both have a heart
- both are a closed system
- both carry o2 using haemoglobin

differences -
- mammals have a double cirrculatory system and fish have a single cirrculatory system
- fish are less efficient at trasporting oxygen
- mammals have a higher metabolic rate

Question 3

Outline how other properties of water are essential for sustaining life on Earth.

Answer 3

• polar
• adhesion
• cohesion
• ice has a higher density so floats
• hydrogen bonds between water molecules
• organisms can survive beneath ice
• ice are habitats for polar bears
• ice can act as a resting place for organisms
• habitat for aquatic organisms