d. O2
This is because CO2 (Carbon Dioxide), energy (sunlight), and H2O (water) are all outputs of cellular respiration.
Proteins
Enzymes are proteins that can lower activation energy of reactions in the body (I think).
Answer:
After four half lives or 32 years, only 12.5 grams will be left.
Hope it helps :)
Answer:
Since the cell membrane is semi-permeable, the likelihood of substance L entering the cell attached to a large protein is lower than that of substance L free in the culture. Substance L enters the cell membrane through active transport, but the cell membrane may block the larger protein, thus blocking substance L, if it is attached to the large protein.
Explanation: