THE CELL
TRANSPORT INTO AND OUT OF THE CELL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The molecules are sucked in automatically through the transport proteins.
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The transport proteins change shape to push the molecules through the membrane of the cell.
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The protein pumps have characteristics which attract molecules from the outside of the cell.
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They just naturally occur without any efforts.
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Detailed explanation-1: -Carrier proteins bind specific molecules to be transported on one side of the membrane. They then undergo conformational changes that allow the molecule to pass through the membrane and be released on the other side.
Detailed explanation-2: -The active transport of small molecules or ions across a cell membrane is generally carried out by transport proteins that are found in the membrane. Larger molecules such as starch can also be actively transported across the cell membrane by processes called endocytosis and exocytosis.
Detailed explanation-3: -Special membrane transport proteins are responsible for transferring such solutes across cell membranes. These proteins occur in many forms and in all types of biological membranes.
Detailed explanation-4: -Transport proteins generally perform two types of transport: “facilitated diffusion, ” where a transport protein simply creates an opening for a substance to diffuse down its concentration gradient; and “active transport, ” where the cell expends energy in order to move a substance against its concentration gradient.
Detailed explanation-5: -Active transport uses carrier proteins, not channel proteins. These carrier proteins are different than the ones seen in facilitated diffusion, as they need ATP in order to change conformation.