active transport. The movement of ions or molecules across a cell membrane in the direction opposite that of diffusion, that is, from an area of lower concentration to one of higher concentration. Active transport requires the assistance of a type of protein called a carrier protein, using energy supplied by ATP.
I believe it will be 200,000 years
Answer:
c. cysteine
Explanation:
Cysteine is a non essential amino acid. It contains sulfur in form of thiol group. A disulfide bond or bridge is formed between two thiol groups. It is represented as S-S. It is formed by oxidation of two cysteine molecules. The resultant disulfide bond is called as cystine which connects two polypeptide chains.
Cysteine is the only amino acid capable of forming disulfide bridge. It stabilizes protein's globular structure and plays an important role in protein folding and stability. Cysteine is required for protein synthesis, metabolic processes and detoxification. It is the part of beta-keratin which is the main protein in nails, hair and skin. If cysteine is mutated, formation of disulfide bond will be affected.
The answer is: B - Mitochondria
Explanation:
The mitochondria is the powerhouse of the cell.
The main function of the mitochondria is to provide energy for cellular activity by the process of aerobic respiration. In this process, glucose is broken down in the cell's cytoplasm to form pyruvic acid, which is transported into the mitochondrion.
Because Precambrian rocks are in short supply, hence fossil evidence is harder to find.they only discovers sections of some Precambrian rocks there were no bones or shells to be permineralized.