Cell Structure and Function

- Cell theory:

• Basic unit of life
• Cells arise from preexisting cells
• All organisms made of cells

- Prokaryotic and eukaryotic cells:

• Prokaryotic: no nucleus or membrane-bound organelles
• Eukaryotic: has nucleus and membrane-bound organelles

- Cell membrane:

• Selectively permeable phospholipid bilayer
• Regulates what enters and exits the cell

- Cytoplasm:

• Jelly-like substance that fills the cell
• Contains all cell organelles

- Nucleus:

• Control center of the cell
• Contains cell’s DNA

- Nucleolus:

• Region of the nucleus where ribosomes are synthesized

- Ribosomes:

• Synthesize proteins

- Endoplasmic reticulum:

• Network of membranes for transport
• Involved in lipid and protein synthesis

- Golgi apparatus:

• Modifies, sorts, and packages proteins and lipids

- Lysosomes:

• Contain digestive enzymes to break down waste and cell parts

- Mitochondria:

• Produce energy for the cell

- Chloroplasts:

• Carry out photosynthesis in plant cells

- Vacuoles:

• Membrane-bound sacs that store materials for the cell

Biomolecules

- Carbohydrates:

• Composed of carbon, hydrogen, and oxygen
• Monosaccharides, disaccharides or polysaccharides

- Lipids:

• Composed of carbon, hydrogen, and oxygen
• Fats, oils, waxes, and phospholipids

- Proteins:

• Composed of Carbon, hydrogen, oxygen, nitrogen, and sulfur
• Amino acids, peptides, and proteins

- Nucleic acids:

• Composed of carbon, hydrogen, oxygen, nitrogen, & phosphorus
• DNA and RNA

- Enzymes:

• Catalyze chemical reactions in the cell