Author Question: Briefly describe protein synthesis in a cell. Include the following terms: nucleus, ribosome, DNA, ... (Read 55 times)

eruditmonkey@yahoo.com · **on:** Aug 21, 2018

Briefly describe protein synthesis in a cell. Include the following terms: nucleus, ribosome, DNA, mRNA, tRNA, amino acids, and cytoplasm.

What will be an ideal response?

Question 2

Under what circumstances are the body's proteins broken down to provide energy for the body? Is this a good thing to have happen?

What will be an ideal response?

daiying98 · **Reply #1 on:** Aug 21, 2018

Answer to Question 1

DNA in the nucleus stores the coded genetic information needed for making proteins. DNA can't leave the nucleus of the cell; instead, messenger RNA (mRNA) made in the nucleus takes a copy of the information to a ribosome in the cytoplasm. The ribosome moves along the mRNA, reading the code. Another type of RNAtransfer RNA (tRNA)picks up an amino acid that is needed to build a specific protein and carries it to a ribosome. (There are 20 different tRNAs, one for each amino acid.) The ribosome then builds the protein by connecting the amino acids in the proper sequence as directed by the code in the mRNA. The ribosome continues to move down the mRNA strand until each of the appropriate amino acids has been added and the protein is complete.

Answer to Question 2

Proteins are broken down to provide energy for the body when caloric intake is inadequate. This is an undesirable situation; the body's energy needs are better met by consuming adequate amounts of calories from carbohydrates and fat, and using proteins to provide energy produces waste products that must be eliminated from the body. Proteins are best reserved for their many important roles other than providing energy.