2023

• B

  
• A

  
• C

  
• A

  
• 
  

  A

  $210/350 × 100$

  
• A

  
• B

  3.5cm^3 = 25 minutes

  0.14cm^3 = 1 minute

  
• D

  
• (a)(i) cell membrane, cytoplasm, cell wall, ribosome

  (ii)cellulose

  
• 65x times bigger

  $52 ÷ 0.8 =$$65$

  
• a plant cell has a vacuole, bacterial cells don't.

  
• the movement of molecules from a LOW concentration to a HIGH concentration against the concentration gradient. this requires energy.

  
• no energy required (passive process)

  
• turgid

  
• base A - adenine

  base C - cytosine

  
• amino acids

  
• Q --> R --> P

  
• The active site of the enzyme is complementary/specific to the substrate.

  
• pH 2.4

  
• The enzyme/active site changes shape

  
• $((348-240) ÷ 240) × 100$

  
• aerobic

  
• (i) substance x --> pyruvate

  (ii) oxygen

  
• muscle : skin

  7000 : 800

  35 : 4

  
• because muscle cells require more energy than skin cells to for example contract.