Question

1. State what the function(s) of the following nuclear components and why each is important to the cell. (Provide details, don’t just say “ribosomes are the location of translation.” What is translation) nuclear envelope, lamins and nuclear lamina, ER, ribosomes, nuclear pore, and nucleolus. Remember, this is a study tool, the more detailed you are here, the better understanding you have of the info.

Answer 1

Nuclear envelop---it is very important to the cell to isolate the DNA from rest of the cellular components. DNA needs to be protected from any changes as it has to pass the genetic information from one cell to its daughter cells with out any changes. Any changes in DNA will result in changes in the phenotype. So to protect the DNA , there is nuclear envelop.

Lamins--They are fibrous proteins which help in the trasncriptional regulation in the nucleus. They interact with inner nuclear proteins to form nuclear lamina.

Nuclear lamina---It is present on the interior of nuclear envelope. Nuclear lamina is made of proteinaceous intermediate filaments. It provides support to the nucleoplasm and also gives shape to the nucleus. It also regulates DNA replication and cell division.

ER--Endoplasmic reticulum provides support to the cytoplasm and also gives frame work. They intracellular channels , through which materials are transported with in the cell in isolation from other chemicals. RER helps in protein synthesis, SER helps in formation glycogen , lipids and steroid hormones. SER also is important in detoxification. RER forms nuclear envelope.

Ribosomes--They are protein synthesizing machinery of the cell. They attach to the mRNA and read the message for the synthesis of proteins. Ribosomes have some enzymes like ribozyme, which are important in the process of protein synthesis,. They provide surface for the attachment of mRNA which brings message for protein synthesis and tRNA which brings amino acids to the site of protein synthesis.

Nuclear pore--They are openings present in the nuclear envelope. They allow large molecules to pass through from and in to the nucleus. For example RNAs, proteins need to be exchanged between nucleus and cytoplasm. This can occur only through nuclear pores.

Nucelolus--It helps in the biogenesis of ribosomes. It has DNA which can transcribe rRNA and pass it on to the cytoplasm, where they assemble along with the proteins to form ribosomes.