A few common mistakes with molecules and cells and membranes 

1. Ions are polar….. - NO - Ions are charged hence they cannot pass through the hydrophobic inside of the Cell Surface Membrane.

2. The nucleolus contains rRNA - NO - the nucleolus synthesizes rRNA (which forms part of ribosome), but it itself is made of DNA (coiled around histones)

3. Fatty acid/ hydrocarbon tails interact with hydrophobic bonds - NO Fatty acid/ hydrocarbon tails interact with hydrophobic interactions

4. Ribosomes have one membrane - NO -  Ribosomes do not have membranes

5. Facilitated diffusion uses only channel proteins. Active transport uses only carrier proteins. NO - Facilitated diffusion uses both channel proteins and carrier proteins. The carrier protein can change conformation without ATP hydrolysis. Active transport uses only carrier proteins which can change conformation only upon ATP hydrolysis

6. Exocytosis is the same as active transport - NO.- Exocytosis is a type of bulk transport requiring vesicles (and ATP to move the vesicles) , while active transport uses carrier proteins.

7. Mitochondria carry out respiration - NO - Mitochondria carry out aerobic respiration