Answer:
the mRNA goes through extensive modifications such as addition of a poly tail and a 5' cap in eukaryotes but not in prokaryotes.
Differences:
- the promoters in prokaryotes have a -35 and -10 box while in eukaryotes they are variable but have a TATA box from
- the transcription initiation site there is a single RNA polymerase in prokaryotes while eukaryotes have multiple RNA polymerases
- the sigma factor associates with the promoter region in prokaryotes but in eukaryotes there are many basal transcription factors
Explanation:
Ribosomal and transfer RNAs are processed both in prokaryotic and eukaryotic organisms. However, mRNA is only processed in eukaryotes. In eukaryotic cells, mRNA processing involves:
1. Capping at the 5' end. This process has several functions including regulation of nuclear export, prevention of eukaryotic mRNA degradation and promotion of translation.
2. Splicing in order to remove introns and conserve coding exons. Splicing helps to increase the diversity of the eukaryotic mRNAs (and therefore eukaryotic proteins)
3. Polyadenylation by the addition of a poly(A) tail at the 3' end. The poly(A) tail makes the eukaryotic mRNA molecule more stable and also prevents its degradation by exonucleases.
its like the human body rectum its there but serves no purpose but when we evolved we eveolved to eat different foods and different foods mean different digestion
Hormones glucagon and insulin are produced in the alpha and beta cells respectively in the Islet of Langerhan in the pancreas. They are involved in the negative feedback system of blood glucose regulation in homeostasis.
GLUCAGON: when there is a low blood glucose concentration, the pancreas detect this and alpha cells produce and release glucagon. Glucagon causes the cells of the body to absorb less glucose from the blood. It also inhibits the process of converting glucose into glycogen (glycogenesis) and cause gluconeogenesis (process of converting amino acids/proteins and lipids/fats into glucose) and glycogenolysis (conversion of glycogen to glucose). Finally, glucagon decreases the rate of respiration so less glucose is required.
INSULIN: when blood glucose is high, insulin is released. Insulin binds with cell surface receptors of cells and activates the enzymes attached to the receptor. The enzymes cause a conformational change in the structural proteins that surround glucose transport protein containing vesicles, causing them to move out of the way so the vesicles migrate up to the cell membrane and glucose transport proteins can fuse with it. Thus, more glucose can be taken in by cells. Insulin also cause glycogenesis (converting glucose into glycogen) and inhibits gluconeogenesis and glycogenolysis.
Basically insulin decreases blood glucose concentration (eg. after eating) and glucagon increases it (eg. skipping breakfast in the morning)
Liver problems. Failing liver. Something with the hippocampus getting smaller, which will cause your memory to leave you.
