Answer:
"As a molecule moves through the plasma membrane it passes through <em>a hydrophilic layer of phospholipid heads then a hydrophobic layer of phospholipid tails and then another hydrophilic layer of phospholipid heads".</em>
Explanation:
Biological membranes are formed by two lipidic layers, proteins, and glucans.
Lipids characterize for being amphipathic molecules, which means that they have both a hydrophilic portion and a hydrophobic portion at the same time. These molecules have a lipidic head that corresponds to a negatively charged phosphate group, which is the polar and hydrophilic portion. They also have two lipidic tails that correspond to the hydrocarbon chains -the apolar and hydrophobic portion- of the fatty acids that esterify glycerol.
Membrane lipids are arranged with their hydrophilic polar heads facing the exterior and the interior of the cells, while their hydrophobic tails are against each other, constituting the internal part of the membrane.
Through this lipidic bilayer, some molecules can move from one side of the cell to the other, which happens because of concentration differences. When this occurs, molecules must pass through the hydrophilic layer of phospholipid heads then through the hydrophobic layer of phospholipid tails and then again through another hydrophilic layer of phospholipid heads.
The study of the relationship between structures and functions is at the very heart of biology. This relationship is expressed in living beings by the adaptation of the first to the second and poses a series of absolutely fundamental problems, such as the relationship between causality and finality, analogy and homology, structural improvement and evolutionary level, etc.
For example, the structure of the hand is related to its function, thanks to the fingers and the thumb it is easy to wear and store objects.
The zigzag structure of the intestine is related to its absorption function, as this makes it possible to increase the contact surface between the alimentary bolus and the intestinal wall, and thus to increase the absorption.
Answer: The differences in the assembly and organization of the monomers of these two polymers result in different chemical properties.
Explanation:
Starch and Cellulose flare both polysaccharides which are constructed from the same monomer called glucose. The functions they provide in plants are different which includes the following:
- STARCH is used by plants for energy storage because unlike Cellulose, it's formed from glucose units( oriented in the same direction) connected by alpha linkages which can form compact structures that can easily be broken down.
- Cellulose provides structural support for plant cell wall because unlike Starch, it's formed from glucose units( which rotates 180 degrees around the axis of the polymer backbone chain) connected by beta linkages. This pattern gives Cellulose it's rigid features as is allows for hydrogen bonding between two molecules of Cellulose.
Therefore the statement that best describes why starch and cellulose provide different functions in plants is that (The differences in the assembly and organization of the monomers of these two polymers result in different chemical properties).
Answer:
The correct answer is "both Cdc6 and Cdt1"
Explanation:
The replisome is a complex molecular system that allows for the replication of DNA in yeast. There are multiple genes that participate in the replisome function, however if a researcher finds out that a yeast strain fails to properly form replisomes it is very likely that the genes that might be mutated are both Cdc6 and Cdt1. Cdc6 and ORC are the genes that send the signal to the yeast to start the replisome formation, and Cdt1 is a DNA replication factor that if it is mutated it could cause that yeast is not able to form the replisome.
Answer:
possible genotypes of offsprings are A.
TT Tt and tt
