Phases or components
Your textbook describes two
sequential phases of interaction between organisms and their environments that
have existed since god's creative work began. Organisms interact with their
environments in different ways. Different organisms of a biological community cooperate
and compete for habitats and share the resources in that habitat.
False .......................................
A monosaccharide is the monomer of a carbohydrate. Carbohydrates, such as sugars and starches, store energy. Some monosaccharides are isomers .This means that they have the same chemical formula but a different arrangement of atoms. An example of such a pair of isomers is glucose and fructose.
i think answer is D animal in the rain forest
Answer:
Te correct answer is "Being transported by specific carrier proteins".
Explanation:
Cholesterol is one of the most important lipids in our body. It is useful for membrane formation and for sexual and suprarenal hormone synthesis. The organism obtains cholesterol from food and liver production. It goes to the blood where it is transported by lipoproteins to its final destiny.
In the intestine, cholesterol is absorbed in three phases:
- <em>intraluminal phase</em>: in this phase micellar formation is necessary for cholesterol absorption. Micellar solubilization is a transport way for cholesterol to diffuse through the mucus barrier that covers intestine surface microvilli. Once there cholesterol is available for intestinal cells.
- <em>mucose phase</em>: in this phase cholesterol pass from the lumen to the cytoplasm of the intestinal cells, and when necessary, from the cytoplasm to the intestinal lumen. In the cells´ membrane, there are proteins that transport cholesterol to and from the interior of the cell.
- <em>Intracellular phase</em>: In the intestinal cell cholesterol is sent to the endoplasmic reticulum where it is reesterified to be transported in the blood. As cholesterol is insoluble it is packaged in lipoproteins to be transported.
Each lipoprotein has a union site that is specific for a target membrane receptor. Lipoproteins get in the target cells by endocytosis mediated by the specific receptors. Once in the interior of the cell cholesterol is taken from the lipoprotein by breaking the ester link, and then they reesterify it to include it in the membrane.
