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)
Answer:
The eukaryotic plant animal cells are differ having some cell organelles in it.
Explanation:
The first difference is the cell wall, which is present in all eukaryotic plants. It gives shape and rigidity to the plants. But all the animal cell the outer covering is cell membrane. They lack cell wall.
All the plant cell have chlorophyll pigment. It helps them to photosynthesis. In animal cell, chlorophyll molecule are absent. So they depend on plants for their food.
The eukaryotic plant cell more space is occupied by the vacuoles. It stores food and water for the plants. However, animal cells have no vacuole or if present, it is very small in size.
All animal cells have lysosomes, which help in digestion of various materials in the cell. Plants does not contain lysosomes.
Besides this organelles all other structure of plant and animals are similar. They both have nucleus, DNA, cytoplasm, mitochondria, etc.
Answer: The correct options are statement first and fourth that is -
It is synthesized toward the replication fork and it is synthesized in the 5′ to 3′ direction.
Leading strand in DNA is the strand of new DNA being synthesized in the same direction where the replication fork is moving. The movement of replication fork allows the access of template for the new DNA.
The DNA synthesis is continuous in the leading strand. It is synthesized in the 5' to 3' as DNA synthesis always takes place in this direction. This is because dNTP ( deoxyribonucleoside triphosphate) provides free 3' OH group where new dNTP can be added by the enzyme DNA polymerase.
A magnifying glass is an example of a simple microscope. The correct answer is will be D, simple microscope.
