How we cite our quotes: (Section.Paragraph)
Quote #4
[The] work of the proletarians has lost all individual character, and, consequently, all charm for the workman. He becomes an appendage of the machine, and it is only the most simple, most monotonous, and most easily acquired knack, that is required of him. (Section1.31)
According to Marx, the proletarians are miserable not just because they're economically exploited by the bourgeoisie, but also because their work is boring and repetitive. It doesn't challenge them, and it doesn't give them the opportunity to really shine. The proletarians are alienated from their own work.
Quote #5
Masses of labourers, crowded into the factory, are organised like soldiers. As privates of the industrial army they are placed under the command of a perfect hierarchy of officers and sergeants. Not only are they slaves of the bourgeois class, and of the bourgeois State; they are daily and hourly enslaved by the machine, by the overlooker, and, above all, by the individual bourgeois manufacturer himself. The more openly this despotism proclaims gain to be its end and aim, the more petty, the more hateful and the more embittering it is. (Section1.32)
Marx argues that the workers are constantly under someone's thumb, not just because the value of their labor is being taken away from them or because they have to obey the police, but because every aspect of their work day is organized to force them into taking orders and being a cog in the machine.
Quote #6
Finally, in times when the class struggle nears the decisive hour, the process of dissolution going on within the ruling class, in fact within the whole range of society, assumes such a violent, glaring character, that a small section of the ruling class cuts itself adrift, and joins the revolutionary class, the class that holds the future in its hands. Just as, therefore, at an earlier period, a section of the nobility went over to the bourgeoisie, so now a portion of the bourgeoisie goes over to the proletariat, and in particular, a portion of the bourgeois ideologists, who have raised themselves to the level of comprehending theoretically the historical movement as a whole. (Section1.43)
Here Marx is talking about himself and others like himself who were born into the bourgeoisie but intentionally defected to the proletariat because they believed the future lay in the hands of the workforce revolutionaries.