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Allie Gruber Human Bio Field Period 1 August 20, 2008 Chapter 3. Cell Structure.

1. What does the cell theory state? A cell is the basic unit of life.

2. Why are cells so tiny? The small size of cells is explained by considering the surface are-to-volume ratio of cells.

3. What are the three main parts of a eukaryotic cell? Plasma membrane, cytoplasm, organelles

4. Explain how the eukaryotic cell gained mitochondria and chloroplasts. The mitochondrion is an organelle that carries on cellular respiration and the chloroplast is an organelle found only in plant cells that carries on photosynthesis.

5. What are glycoproteins, and what functions do proteins, including glycoproteins, have in the plasma membrane? The plasma membrane marks the boundary between the outside and the inside of the cell. The proteins such as glycoprotein’s help mark it as belonging to particular to individuals.

6. What is endocytosis and exocytosis, and how do they occur? During endocytosis, a portion of the plasma membrane forms a pouch to envelop a substance and fluid. During exocytosis a vesicle fuses with the plasma membrane as secretion occurs.

7. The nucleus, ribosome’s, and rough endoplasmic reticulum make what contribution to protein synthesis? The nucleus stores genetic information and the ribosome’s is where protein synthesis occurs. Ribosomes are often attached to the endoplasmic reticulum, which is a membranous system of saccules and channels.

8. The endoplasmic reticulum and the Golgi apparatus make what contribution to the processing of proteins? The endoplasmic reticulum synthesizes proteins and packages them in vesicles while the Golgi apparatus modifies the lipids and proteins from the ER; sorts and packages them in vesicles.

9. What is the function of smooth endoplasmic reticulum and lysosomes? The smooth endoplasmic reticulum synthesizes lipids and has various other functions while lysosomes contain digestive enzymes that break down cell parts or substances entering by vesicles.

10. What is the function of the mitochondria? The mitochondria is a membrane-enclosed organelle that generates most of the cells supply of energy.