Cells Chapter 2 Page 48

Cell theory: Robert Hooke first looked at and described cells in The word “cell” means “little room” in Latin. Cell theory: Robert Hooke first looked at and described cells in The word “cell” means “little room” in Latin. Anton Leeuwenhoek first described protists, blood cells, and bacteria in the later 1600s. Anton Leeuwenhoek first described protists, blood cells, and bacteria in the later 1600s. We now know all living things are made of cells. Cell theory, written in the 1800s, says three things: 1. All organisms are made of one or more cells. We now know all living things are made of cells. Cell theory, written in the 1800s, says three things: 1. All organisms are made of one or more cells. 2. The cell is the basic unit of life. 3. All cells come from existing cells.

PARTS OF A CELL: Cell membrane -protective layer; acts as barrier; controls what goes in and out Cytoplasm-the fluid and it’s dissolved contents inside the cell Organelles: carry out various processes within the cell; most have their own membranes; some float in cytoplasm Nucleus: Only present in Eukaryotic (cells with nuclei) cells; contains the DNA in eukaryotic organisms (not bacteria)

Eukaryotic Cells p. 56 Include plants and animals Include plants and animals All have a nucleus -large organelle w/ DNA; DNA directs the production of proteins; covered by two membranes; contains the nucleolus (where ribosomes are made) All have a nucleus -large organelle w/ DNA; DNA directs the production of proteins; covered by two membranes; contains the nucleolus (where ribosomes are made)

Plant Cells The main differences in plant and animal cells is that plant cells have a cell wall (provides support) and chloroplasts (where photosynthesis takes place). Plants’ cell walls are made of cellulose, a complex sugar. This is why celery crunches when you bite it. Chloroplasts have their own membranes and DNA. They contain chlorophyll, which makes them green. This is also what traps the energy of sunlight.

All Eukaryotic Cells have these… Cell membrane -contains proteins, lipids, and phospholipids; lipids are fat and do not dissolve in water; protein passageways allow movement of materials in and out. Cell membrane -contains proteins, lipids, and phospholipids; lipids are fat and do not dissolve in water; protein passageways allow movement of materials in and out. Cytoskeleton -keeps the cell’s membranes from collapsing and allows some to move Cytoskeleton -keeps the cell’s membranes from collapsing and allows some to move Ribosomes -make proteins; smallest organelles; more than any other organelle in a cell; some are attached to the rough ER (prokaryotes have ribosomes too!) Ribosomes -make proteins; smallest organelles; more than any other organelle in a cell; some are attached to the rough ER (prokaryotes have ribosomes too!)

Endoplasmic Reticulum (ER): system of folded membranes in which proteins, lipids and other materials are made through chemical reactions. Rough ER makes proteins; smooth ER makes lipids and breaks down toxins. Endoplasmic Reticulum (ER): system of folded membranes in which proteins, lipids and other materials are made through chemical reactions. Rough ER makes proteins; smooth ER makes lipids and breaks down toxins. Mitochondria: “powerhouse” of the cell; sugar is broken down here to make energy (ATP) through cellular respiration; energy is found in ATP (adenosine triphosphate) Mitochondria: “powerhouse” of the cell; sugar is broken down here to make energy (ATP) through cellular respiration; energy is found in ATP (adenosine triphosphate)

Golgi Complex (apparatus) Packages and distributes proteins; looks like smooth ER but is farther from the nucleus; gets lipids and proteins from the ER; modifies them to do different jobs then sends them out of the cell Packages and distributes proteins; looks like smooth ER but is farther from the nucleus; gets lipids and proteins from the ER; modifies them to do different jobs then sends them out of the cellVESICLE Small sac that surrounds material to be moved in or out of a cell. Small sac that surrounds material to be moved in or out of a cell.

REVIEW-write Q and A in Assignments Section 1. Explain how the mitochondria and chloroplast are related in a plant cell: 2. Make a chart showing how a plant and animal cell differ. 3. How do the Golgi complex and endoplasmic reticulum work together? 4. How does smooth ER differ from rough ER?

Review-put in Assignments-write Q and A 1. Why do you think plants need a cell wall? 2. What is the function of the mitochondria? 3. Ribosomes make ____________but ribosomes are made in the __________ 4. The rough ER is covered in ________. 5. The smooth ER makes __________. 6. How are mitochondria and chloroplasts alike? 7. (sect 3) What are the three advantages to being multicellular?

REVIEW-ASSIGNMENTS-WRITE OUT 1. Compare and Contrast mitochondria and chloroplasts. 2. Explain the relationship between the Golgi Complex and the ER. 3. What does the vacuole do? 4. What does the lysosome do? 5. What is the “powerhouse” of the cell? 6. What is the difference in the rough ER and the smooth ER? (p. 59) 7. What are the two main differences in a plant and animal cell? 8. What is a lipid and how is it used in your cells?