Which statement is not true about ribosomes?
1) Ribosomes build proteins by following the directions of the DNA.
(2) Ribosomes are made in the cytoplasm of the cell.
(3) Ribosomes can occur attached to the endoplasmic reticulum as well as free in the cytoplasm.
(4) Ribosomes are not bound by a membrane
Answers
Answer:
Ribosomes are not bound by a membrane.
Explanation:
Ribosomes are unique structures due to lack of membranes around them. Ribosomes translate the DNA code via mRNA into proteins. Ribosomes are two types: rough and smooth.
Ribosomes are found in both prokaryotes and eukaryotes. In prokaryotes, ribosome freely float in cytosol due to absence of any membrane organelles. In eukaryotes, smooth ribosomes are found floating in cytosol while rough ribosomes are attached to endoplasmic reticulum.
Ribosomes consist of two subunits where smaller subunit 40-S reads the mRNA and the larger subunit 60-S engages with amino acids to form protein chain. Few thousand ribosomes are present in a cell. Ribosome numbers are variable as per the need of the cell. Prokaryotic ribosomes are made of 50-S and 30-S subunits.
The correct answer to your question is option (D)
Ribosomes are not bounded by a membrane is the statement that is not true about it.
Ribosomes are the site of protein synthesis that is present in every cells bounded by a membrane. They are complex molecular machines and can be found in all living cells. Linking amino acids is the major role of ribosome that too in the order that marked by the Messenger RNA molecules.