2.

One of the grand challenges in biology is understanding how the first cells formed on Earth. Since all cells are bound by a cell

coldgirl [10]

<h2>Answer is option "A"</h2>

Explanation:

Oils and fats, which in science are called lipids, are known as amphipathic molecules. These molecules have two distinct ends to them: a water-loving (hydrophilic) side and a water-fearing (hydrophobic) side. While the hydrophilic sides of a lipid will associate with the water in a solution, the hydrophobic sides of the lipid all cluster together to 'hide' from the water. Lipids therefore cluster together and form spheres where the hydrophobic sides are in the center away from the water while the hydrophilic sides are on the outside, associating with the water.
The ability of the atoms within a group to form hydrogen bonds with the water molecules around them makes them hydrophilic. Oxygen and nitrogen atoms readily form hydrogen bonds with water molecules, so any organic molecules that have oxygen or nitrogen atoms bound to their carbon skeletons will be hydrophilic.
For example, if we take the molecule for cholesterol, we see the OH group on the left is hydrophilic and will form hydrogen bonds with water, while the ring structures, which only consist of hydrogen and carbon atoms, are hydrophobic and will not associate with the water.
There are many different kinds of lipids with different functions. Lets start by examining phospholipids, which compose the cell membranes of animals. They form lipid bilayers, with one set of hydrophilic heads facing the exterior of the cell membrane and the other set facing the interior (as you can see on the diagram on screen). The hydrophobic portions of the lipid bilayer - the lipid tails - face towards one another, which allows them to hide away from the water inside and outside of the cell.
So,the right answer is option A "amphipathic molecules".

5 0

4 years ago

The role of rRNA in gene expression is to?

Verizon [17]

Answer:

The correct answer is rRNA plays an important role during translation (protein synthesis) of mRNA.

Explanation:

Ribosomal RNA or rRNA are the RNA molecules which build up the site for protein synthesis known as ribosomes.

Ribosome synthesis takes place in nucleolus where two types of rRNA molecules associates with proteins, one in large subunit and one in the small subunit to form ribosomes.

These ribosomes physically moves along an mRNA molecule and catalyze the assembly of amino acids where rRNA molecules performs the catalytic steps of protein synthesis that is stitches amino acids together and makes up proteins.

Thus, rRNA plays an important role during translation (protein synthesis) of mRNA.

4 0

3 years ago

What is biodiversity an indicator of? A. ecosystem health B. ecosystem growth C. ecosystem decline D. ecosystem location

sattari [20]

Your answer is A, hope it helps!

4 0

3 years ago

Learning Task No. 2: Copy and complete each statement. Choose from the

Lunna [17]

Answer:

1. Aorta

2. Left atrium

3. Right ventricle

4. The pulmonary artery

5. Left ventricle.

Explanation:

The aorta is the main artery of the body that carries the oxygen-rich blood to all the body parts except the lungs from the left ventricle. It is divided into main coronary arteries or blood vessels.

The left atrium is one of the heart chambers, it is located in the upper part of the heart on the right side that receives the oxygenated blood from the lungs through the pulmonary vein.

The right ventricle is the chamber of the heart that pumps the deoxygenated blood to the pulmonary valve to MPA to the lungs to get oxygenated.

The pulmonary artery or the main PA (MPA) carries the oxygen-depleted blood from the right ventricle into the lungs, where blood becomes oxygenated.

The Left ventricle is the thickest muscle chamber of the heart responsible for the pumping oxygen-rich blood to the circulatory system and to the body through the aorta.

8 0

3 years ago

5 points for a easy question

kompoz [17]

Globalized evolution...... but I might be wrong

6 0

3 years ago

Read 2 more answers