Prokaryote Metabolism and Ecology quiz Flashcards

Auxin, a plant hormone, is responsible for promoting plant growth towards light by causing cells on the shade side to elongate more than those on the light side.

The acid growth hypothesis suggests that proton pumps increase proton concentration in the cell wall, loosening cellulose bonds and allowing water to enter, causing cell elongation.

Auxin moves from the light side to the shade side, causing asymmetric growth that bends the plant towards the light source.

Expansins are proteins that loosen hydrogen bonds in cellulose, allowing water to enter the cell wall and facilitating cell elongation.

The electrochemical gradient, created by proton pumps, brings potassium ions into the cell, followed by water through aquaporins, leading to cell swelling and elongation.

Polar transport is the unidirectional movement of auxin from the shoots to the roots, regardless of gravity.

Auxin influences phyllotaxy, the arrangement of leaves on a stem, to optimize light absorption.

Proteobacteria are a diverse clade of gram-negative bacteria, some of which are involved in nitrogen fixation and were precursors to mitochondria.

Chlamydia bacteria lack peptidoglycan in their cell walls and are obligate intracellular parasites.

Spirochetes are gram-negative heterotrophs with a corkscrew shape, known for causing Lyme disease and syphilis.

Aquaporins are channels that facilitate water movement into plant cells, aiding in cell swelling and elongation.

Auxin maintains apical dominance by promoting the growth of the central stem over lateral stems.

Proton pumps increase proton concentration in the cell wall, leading to loosening of cellulose bonds and water entry.

Auxin regulates leaf shedding, or abscission, by responding to light availability and other environmental factors.

The 3 domains (Bacteria, Archaea, and Eukarya) represent the highest level of classification, distinguishing major evolutionary lineages.