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.
<span> the sea floor is youngest near a mid </span>
<span>ridge and farther away.
i think this is the answer</span>
Answer:
<em>D. Molecules are made of atoms of the same element or different elements.
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Explanation:
Molecules are made up of atoms. The atoms forming the molecule can be same or different. The size and function of the molecules vary from each other. The properties and function of atoms change as and when it forms a molecule.
The atoms combine with the help of a bond and it can be a covalent bond or ionic bond or hydrogen bond to form a molecule. The bond between the atoms gives shape to the molecule.
Photosynthesis removes carbon dioxide naturally—and trees are especially good at storing carbon removed from the atmosphere by photosynthesis.
Answer: Food, Water, Shelter and Space
Explanation: In the natural world, limiting factors like the availability of food, water, shelter and space can change animal and plant populations. Other limiting factors, like competition for resources, predation and disease can also impact populations.
