3.How do cells overcome the energy requirement of active transport?
Active transport uses energy stored in ATP to fuel the transport. Active transport of small molecular-size material uses integral proteins in the cell membrane to move the material—these proteins are analogous to pumps..To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells. In fact, cells spend much of the energy they harvest in metabolism to keep their active transport processes running. For instance, most of a red blood cell’s energy is used to maintain internal sodium and potassium levels that differ from those of the surrounding environment.
Active transport mechanisms can be divided into two categories. Primary active transport directly uses a source of chemical energy (e.g., ATP) to move molecules across a membrane against their gradient. Secondary active transport (cotransport), on the other hand, uses an electrochemical gradient – generated by active transport – as an energy source to move molecules against their gradient, and thus does not directly require a chemical source of energy such as ATP. We’ll look at each type of active transport in greater detail below.
One of the most important pumps in animal cells is the sodium-potassium pump, which moves Na^++start superscript, plus, end superscript out of cells, and K^++start superscript, plus, end superscript into them. Because the transport process uses ATP as an energy source, it is considered an example of primary active transport.
What is the critical difference between passive and active transport? A. passive requires energy but active does not B. passive requires no energy, but active does C. passive and active each require energy, but passive requires less What is an enzyme? A. a protein that facilitates a reaction B. a protein that supplies water for hydrolysis reactions C. a protein that absorbs water during dehydration reactions The First Law of Thermodynamics states: A. energy can be changed from one form...
Secondary active transport relies on coupling of two transporters and requires energy. What form of energy is used by each of the coupled transporters in secondary active transport?
How do bulk, active, and passive transport move drugs through the body and into the brain
which of the following transport mechanisms does not require additional energy expenditure A. active transport b. carrier-mediated diffusion C. simple diffusion
15.Mycoplasma cells don't have cell wall. What is the shape of these cells and how do these reinforce their cell membrane? 16.What are some of the functions of the bacterial plasma membrane? 17.What is meant by active transport of a solute?
47. Active transport of solutes is mediated by and in plant and animal cells, respectively A. H-pump and Ca-pump B. K-pump and Ca-pump C. Na-pump and H'-pump D. H-pump and Na"-pump E. C & D 48. One is NOT TRUE about integral membrane proteins. A. They can move inside the lipid bilayer B. Their hydrophobic amino acid side chains face the lipid bilayer C. Their hydrophilic amino acids form the hydrophilic pore D. They can easily by separated from the...
Why does active transport require an input of energy (needs to include equilibrium and the laws of thermodynamics in the answer) Explain the difference between primary and secondary active transport, provide examples of each.
The energy for __________ transport comes from the gradient of the thing being transported. A) active B) facilitated C) passive D) pumped E) ATP-mediated
how do determine a person’s protein and energy requirement.
1. The orientation of phospholipids in water occurs spontaneously. Why? 2.You board the Magic School Bus and go on a microscopic adventure to visit the plasma membrane of a cell. All of a sudden, the temperature dropsand the cell membrane starts to get too solid!!! Oh no! To combat this decrease in fluidity, the cell starts firing new phospholipids up to the plasma membrane! What would the composition of these lipids look like (i.e. saturated vs unsaturated fatty acids, cholesterol?)...