Answer:
Channel proteins and Carrier proteins
Explanation:
These are type of membrane proteins that transcend the entire length of phosphoslipid bi- layer in the plasma membrane.They facilitate the movement of ions and molecules across the walls of the plasma membranes.
Generally, substances like glucose, amino acids, are too large to pass through the phopholipid bilayers. Likewise ions of potassium, sodium calcium, because of their polarities can not pass through either. They are ferried across the phospholipid by group of protein structures called channel proteins. Some are also transported across by carrier proteins. The process by which these protein structures aided the diffusion of substances across the phospholipid bilayer is called Facilitated diffusion.
Channel proteins are pores, that are filled with water molecules with the entrance well gated. That is the entrance is controlled by part in the inner structure of the protein which can open or close the pores like a gate to control the movement of ions across it. e.g Sodium channels are gated for movement of sodium ions by voltage or ligands(chemicals) during nervous transmission to elicits action potential. Like wise Potassium channels allow diffusion of potassium ions across the phospholipid bilayers. it gates are shut when sodium channels are open; this regulate ion exchange.
Their structures are well fixed in shape , specific to the substance or ions being transported;and the rate of diffusion depends on the like hood of opening of the gate or closure.
Carrier molecules also in the membranes do not have a fixed shape, and their transport direction is determined by the direction of concentration gradients. Thus they can flip on either sides of the membranes to aid diffusion across. Their movement can be both passive and active, and the rates of diffusion depends on the number of available carrier proteins in the membrane. They are also specific to the ions they transport.And are not gated,
Therefore these two membrane integral proteins facilitate movements of substances across the phospholipild bilayers
Answer: the answer is b
Explanation: cells are able to synthesize their entire complement of
Biomolicules
Well the finches there vary all over the islands there are many different ones who are similar but have a slight varitaion
Answer:
It is a mixture.
Explanation:
Car battery is mixture because it contain sulfuric acid and water. A mixture is a substance that contain two or more substances which are mixed physically or physically combined and are not chemically combined but can also be separated into the different substance.
Claim: No tools to discover the impending Cell Theory.
Reasoning:
Schleiden and Schwann, as well as Virchow, are generally seen as the founders of the cell theory, due to their pioneering scientific work in the 1800s. The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.
Evidence: The cell theory has many complexities and is of importance due to its affect to nearly every aspect of biology, from our comprehension of life & death, managing diseases, cycles and etc. But early scientists had no tools to study cells. They didn't even know about them. It took the invention of the microscope to view them and to begin an understanding of cells.
(Two Dutch spectacle-makers and father-and-son team, Hans and Zacharias Janssen, create the first microscope.) Matthias Schleiden observed that all plants were made of cells from the microscope and Theodor Schwann observed that all animals were also made of cells. Rudolf Virchow observed that cells only come from other cells Virchow saw cells dividing and added that living cells arise only from other living cells. These ideas led to cell theory, which states that all organisms are made of cells, all life functions occur in cells, and all cells come from other cells.
