【单选题】Sugar Power for Cell Phones Using enzymes commonly found in living cells, a new type of fuel cell produces small amounts of electricity from sugar. If the technology is able to succeed in mass product...
A.
When enzymes can be commonly found in living cells.
B.
When the technology of producing a new type of fuel cell appears.
C.
When the technology of a new type of fuel cell is suitable for mass production.
D.
When the technology of mass producing cell phones appears.
【简答题】完形填空: Electricity-Generating Tinted Windows Reveal a Sustainable Future Researchers have developed a new type of tinted "smart window" that generates electricity when darkened. The windows "can be __1...
【多选题】How do actin-binding proteins influence the type of protrusions formed at the leading edge of the cell?
A.
The formation and growth of actin filaments at the leading edge of a cell are assisted by various actin-binding proteins. The actin-related proteins (ARPs) promote the formation of a web of branched actin filaments in lamellipodia.
B.
ARPs form complexes that bind to the sides of existing actin filaments and nucleate the formation of new filaments, which grow out at an angle to produce side branches. With the aid of additional actin-binding proteins, this web undergoes continual assembly at the leading edge and disassembly further back, pushing the lamellipodium forward.
C.
The other kind of cell protrusion, the filopodium, depends on formin, a nucleating protein that attaches to the growing plus ends of actin filaments and promotes the addition of new monomers to form straight, unbranched filaments.
D.
Formins are also used elsewhere to assemble unbranched filaments, such as in the contractile ring that pinches a dividing animal cell in two.