1. What are the various functions of endoplasmic reticulum?
2.DifferentiatebetweenRERandSER.
3.Whatarechromosomes?Writetheircompositionandfunction.
4.Writeshortnoteongolgibodies.
Answers
Answer:
1. It is responsible for the production and secretion of steroid hormones.
It is also responsible for the synthesis of essential lipids such as phospholipids and cholesterol.
It is responsible for the metabolism of carbohydrates.
ER releases calcium ions, which are necessary for the nervous system and muscular system.
2. Smooth ER appears like containing many circular marks which are the interlocking tubular sheets, while Rough ER looks like the arrangement of the double membranes which are spotted with the ...
Smooth ER is found near the cell membrane and Rough ER is found near the cytoplasm of the eukaryotic cells.
Smooth ER originates from rough endoplasmic reticulum by giving off the ribosomes, while Rough ER originates from nuclear membrane.
3. A chromosome is a DNA (deoxyribonucleic acid) molecule with part or all of the genetic material (genome) of an organism. Most eukaryotic chromosomes include packaging proteins which, aided by chaperone proteins, bind to and condense the DNA molecule to prevent it from becoming an unmanageable tangle. This three-dimensional genome structure plays a significant role in transcriptional regulation.
DNA — 40%
RNA — 1.5% (Helps in synthesis of chromosomal fibres)
Histone (Protein) — 50%.
Non-Histone (Protein) — 8.5%;
Some amount of calcium which is attached with DNA. DNA is the chief and most significant part of chromosome)
They control the physiological behavior of an organism with the help of genes present in them.
We know each chromosome is made up of DNA and this DNA by replication gives rise to messenger RNA (mRNA) which carry the genetic information in the form of code.
This mRNA comes out of the nuclear wall into the cytoplasm where it helps to form a particular kind of protein needed by the cell or body.
4.
The Golgi apparatus, also known as the Golgi complex, Golgi body, or simply the Golgi, is an organelle found in most eukaryotic cells. Part of the endomembrane system in the cytoplasm, it packages proteins into membrane-bound vesicles inside the cell before the vesicles are sent to their destination. It resides at the intersection of the secretory, lysosomal, and endocytic pathways. It is of particular importance in processing proteins for secretion, containing a set of glycosylation enzymes that attach various sugar monomers to proteins as the proteins move through the apparatus.
1. Rough endoplasmic reticulum functions as;
-protein translocation, folding and transport of protein;
-glycosylation (this is the relation of a saccharides group with a hydroxyl or amino functional group to form a glucoside);
-disulfide bond formation (disulfide bonds stabilize the tertiary and quaternary structures of many proteins);
-membrane synthesis.
Smooth Endoplasmic Reticulum functions as;
-synthesis of lipid
-metabolism of carbohydrates;
-detoxification function;
-major storage and released site of inter cellular calcium ions.
2. RER-Consist of mainly cisternae-Bears ribosomes on its cytoplasmic surface-Usually lies deep in the cytoplasm-Takes part in tje synthesis of proteins-Gives rise to SER-Contains ribophorins for binding ribsomesRER-Consists mainly of tubules and vesicles.-Is free of ribosomes-Usually lies near the cell membrane-Takes part in the synthesis of lipids, steroids and glycogen-Gives rise to Golgi Apparatus, lysosomes and vacuoles.-Ribophorins are lacking.
3. A threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
Function of a Chromosome The chromosome holds not only the genetic code, but many of the proteins responsible for helping express it. Its complex form and structure dictate how often genes can be translated into proteins, and which genes are translated. This process is known as gene expression and is responsible for creating organisms.
4.Golgi apparatus. Golgi apparatus, also called Golgi complex or Golgi body, membrane-bound organelle of eukaryotic cells (cells with clearly defined nuclei) that is made up of a series of flattened, stacked pouches called cisternae