Answer:
In order to be useful in treating human infections, antibiotics must selectively target bacteria for eradication and not the cells of its human host. Indeed, modern antibiotics act either on processes that are unique to bacteria--such as the synthesis of cell walls or folic acid--or on bacterium-specific targets within processes that are common to both bacterium and human cells, including protein or DNA replication. Following are some examples.
Most bacteria produce a cell wall that is composed partly of a macromolecule called peptidoglycan, itself made up of amino sugars and short peptides. Human cells do not make or need peptidoglycan. Penicillin, one of the first antibiotics to be used widely, prevents the final cross-linking step, or transpeptidation, in assembly of this macromolecule. The result is a very fragile cell wall that bursts, killing the bacterium. No harm comes to the human host because penicillin does not inhibit any biochemical process that goes on within us.
hope this helps :) can i get brainliest?
Explanation:
Answer:
mitochondrion / mitochondria coming from the apex.
18. <em>Penny</em>: Used to measure mineral toughness; <em>Cuprum</em> penny's toughness is 3.
<em>Hand Lens</em>: Could be used to measure the hardness of the mineral; the glass can be used as a scratch platform; it can also be used to test the luster of the mineral tile; the mineral is rubbed in the glass portion of the tile and a powdery strike of the stone is given to distinguish the colour of the rock.
<em>Geological hammer</em>: Used to break down the mineral to assess whether or not it has cleavage, and to detect fractures
<em>Pocketknife</em>: Used to define mineral tenacity; the tenacity of the mineral can be silky, malleable, sectile, elastic, or flexible.
17. Volcanoes are holes or cracks in the lava-flowing crust of the earth. They are normally placed on the borders of tectonic plates as they are created as the plates clash and create gaps. In other words, volcanoes located at convergent-plate boundaries.
I am joyous to assist you anytime.
