Pg:-26 (I have already read till Pg:33 but this is based on my notes.)

#biology #textbook #cytoplasm #cellmembrane #nucleus

Cytoplasm:

• The cytoplasm is about 90% water, with molecules of salt and sugar dissolved in it.

• Enzymes control the rate and type of chemical reactions that take place in cells(This is all in the cytoplasm)

• Some enzymes are attached to the membrane systems of the cell, while others float freely in the liquid part of the cytoplasm.

Cell membrane:

• A cell membrane is a thin layer of cytoplasm around the outside of the cell.

• It stops the cell contents from escaping and controls which substances can enter and leave the cell.

• Oxygen, food, and water are allowed to enter; waste products are allowed to leave; and harmful substances are kept out.

Nucleus:

• Most cells contain one nucleus.

• The function of the nucleus is to control the type and quantity of enzymes produced by the cytoplasm.

• The nucleus controls what cell the cell will be, Like muscle cell or never cell, etc.

• The nucleus also controls cell division.

• Inside the nucleus are thread-like structures called chromosomes, which is seen when the cell is dividing.