so carbon is essential to life on Earth.
Answer:
C. carrier proteins
Explanation:
The core of the cell membrane is made up of hydrophobic tails of phospholipid. It does not allow the water-soluble material to move across the membrane. Carrier proteins are the membrane proteins that serve as transporters.
The carrier proteins bind the ion or water-soluble molecules and undergo changes in shape. This transports the molecule across the membrane. Carrier proteins serve in passive facilitated diffusion and active transport. The carrier proteins involved in facilitated diffusion transport the molecules down the concentration gradient without any expenditure of energy.
Answer:
D
Explanation:
Hydroxide ions make solutions more basic by decreasing its acidity (this is accomplished by reacting with H+)
The development of cell theory serves to show the rigorous activities that must be accomplished before a theory can be developed. A scientific theory is a tested and acceptable explanation for a particular observation. A scientific theory usually started as an observation. The observation is use to formulate an hypothesis which is then tested by carrying out an appropriate experiment. If the experiment confirms the hypothesis to be true, then other scientists from different parts of the world will carry out their own experiments in order to confirm the result of the experiment.
When the result of the experiment has been tested continuously for a long time and find to be true, then it becomes a theory. This is the chains of activities which the observations made in cells undergo before it becomes cell theory.
